Abstract
Nanostructured spinel ferrites have gained a great deal of attention. It comes from the possibility of tuning their magnetic properties by careful manipulation of the synthetic conditions. At the same time, since the nanoparticle (NP) surface is reactive toward many chemical groups, it provides great versatility for further functionalization of the nanosystems. Such characteristics make ferrite nanoparticles excellent candidates for environmental applications. First, the chapter deals with the basics of the synthetic methodologies, functionalization strategies and magnetic properties of nanoparticles, with emphasis on how surface manipulation is reflected in the properties of the materials. Next, we review some of the applications of ferrites as magnetic sorbents for several hazardous substances in aqueous medium and try to systematize the adsorption mechanism as a function of the coating material. Finally, a short summary concerning the main uses of ferrites as magnetic catalysts in oxidation technologies is included.
Keywords
- spinel ferrites
- superparamagnetism
- surface complexes
- heavy metals
- dyes
1. Introduction
Magnetic nanoparticles (NPs) have been the focus of intense studies, both at the fundamental and at the technological level. Among many promising materials, nanostructured spinel ferrites occupy a special place. These iron oxide‐based materials are easy and cheap to synthesize, are stable under a wide range of conditions and some family members present low toxicity for living organisms. Besides, due to their high reactivity toward several organic groups, ferrite surface offers a great versatility for ligand functionalization, which in many cases defines the ultimate application. In addition, one of the most prominent properties of spinel ferrite NPs is the onset of superparamagnetism. This phenomenon is a crucial feature for several biomedical applications [1], catalytic processes [2, 3] and environmental remediation strategies [1, 4–7]. Currently, there are available in the literature several extensive reviews covering these issues in detail [8, 9]. In this chapter, we focus primarily on adsorption and oxidation technologies for water decontamination using nanostructured spinel ferrites where particle functionalization plays a major role. In particular, we focus on basic topics concerning spinel ferrite NPs with an emphasis on the surface manipulation by chemical methods and how it is reflected in the properties and performances of the ultimate nanomaterial. Also, attention is paid to the machinery that governs the adsorption process in order to try to systematize the available data. Every step in this direction is aimed to improve and design newer and better solutions for the great challenge of water remediation.
2. Structural and magnetic properties
Spinel ferrites are mixed valence oxides where oxygen anions form a close‐packed cubic array, while metallic cations occupy randomly one‐eighth of the tetrahedral (
In the spinel structure (left panel of Figure 1), magnetic moments of sublattice
2.1. Nanomagnetism
Magnetic NPs differ from bulk magnetic materials mainly due to the finite size and surface effects. The reduction of size leads to a single magnetic domain at a particular size and the onset of superparamagnetism, while surface effects result in symmetry breaking of the crystal structure, which could also alter the magnetic properties. These new features are treated briefly below.
2.1.1. Single‐domain limit
Large magnetic particles usually have a multidomain structure, each domain separated from its neighbors by domain walls. As the particle diameter
Here,
Here,
2.1.2. Superparamagnetism
The product
Here, τ0 is a characteristic time of the system and the actual magnetic state at a given
One of the main advantages of ferrites is the possibility for tuning the magnetic properties by varying simply either the divalent cation or the arrangement of the metals into the spinel structure. For instance, in a series of nanoparticle ferrites MFe2O4 (M = Mn2+, Fe2+, Co2+, Ni2+, Zn2+), Mohapatra
2.1.3. Surface effects
Progressive decrease in NPs’ size makes the number of atoms on the surface comparable with the number of atoms in the bulk. For magnetic NPs, this trend lowers
The effect of surface coating in order to tune the magnetic properties of NPs is another area of active investigations. The adsorption of organic ligands could alter the particle size distribution, the interparticle interactions and the spin canting at the surface [21]. The overall effect seems to be the result of a complex interplay between the coordination mode, the capping density and the surface disorder in the synthesized sample [22]. In a careful study of adsorption of stilbene carboxylates and phosphonates as capping agents of 39 nm Fe3O4 NPs, Daou
In an interesting paper, Vestal and Zhang [28] performed a systematic study of the correlation between the nature of the capping ligand (substituted benzenes) and the magnetic properties of MnFe2O4 ferrites with different particles’ diameter. They found that for very small NPs (4 nm),
2.1.4. Magnetic interparticle interactions
The presence of magnetic interactions between particles has a great influence on superparamagnetism [31–33]. This effect alters the energy barrier for coherent rotation, which is no longer governed by only anisotropic contributions. The system becomes very complex and results in the difficulty to separate the contributions of different factors [34]. For ferrite NPs, the ordinary kinds of magnetic interactions are dipolar‐dipolar and direct exchange interactions between spins at the interface of particles in close contact [35]. The first contribution is almost ubiquitous in any system, given its anisotropic and long‐range nature, which could favor either ferro or antiferromagnetic alignment of the spins. The minimization of such an effect can only be achieved in samples where individual particles are well separated from each other, either by steric or by coulombic repulsions [25, 36]. The dipolar magnetic field generated by a single spherical particle is proportional to its volume; hence, the effect is more pronounced for large particles. In that case, the magnetic energy between two spheres decays with
In the presence of interparticle interactions (IPI), Eq. (4) for
Here,
In Eq. (6),
3. Synthesis
Synthesis of spinel ferrite NPs is a challenging task owing to their colloidal nature. A good methodology must yield well‐dispersed particles with uniform size and good crystallinity; besides, it is desirable that the synthetic setup allows for the tuning of structure and properties of the materials by simple modification of the conditions. Other important features entail the use of nontoxic reagents, low‐temperature processes and the requirement of simple scalable operations. The procedures for the synthesis of ferrite NPs are given in several reviews [2, 8]. Here, we outline some of the most common examples.
3.1. Co‐precipitation
Co‐precipitation is straightforward and efficient and can be extended for a wide variety of simple and mixed ferrites [12, 43, 44]. This method, developed by Massart, consists of the joint precipitation of an aqueous solution containing inorganic salts in the proper stoichiometry by increasing the solution pH. Ageing of the resulting particles can be assessed at room or higher temperatures. By changing experimental conditions (e.g., concentration of metal precursors, pH of the final solution, anion of initial salts, reaction time, reaction temperature and ionic strength), it is possible to obtain a wide variety of particle sizes and shapes [45, 46]. The main drawback relies on the difficulties for a proper separation of nucleation and growth stages, which leads to relative broad size distribution [45]. Besides, in some instances, the resulting powder is subjected to thermal annealing to enhance crystallinity [12, 43].
Nucleation and growth of NPs can be affected by the addition of surfactant molecules like sodium dodecyl sulfate [47], poly(acrylic) acid (PAA) chains [48] and hexadecyl trimethylammonium bromide (CTAB) [49]. Variations in the surfactant content give rise to different particle sizes and morphologies of the as‐synthesized material. Other employed additives aiming to decrease the particle size dispersion are polymeric matrices like cellulose [50] and chitosan [51, 52]. A similar approach entailed the use of graphene oxide (GO) during the co‐precipitation step. After the formation of the ferrite/GO composite, GO is reduced to yield porous nanocomposites containing superparamagnetic ferrite NPs and reduced GO (rGO) is used as a functional material. The resulting material possesses high surface area since rGO avoids ferrite particle agglomeration. Ni, Co and Mn ferrites/rGO nanocomposites have been synthesized with this strategy [53–55]. Alternatively, some investigations have reported the use of organic amines, which can act as precipitating and stabilizing agents [17, 56, 57]. Alkanolamines limit and control the particle growth by forming surface complexes with M2+ cations resulting in a marked reduction in Co ferrite size as compared when using NaOH [56].
3.2. Thermal decomposition
This method utilizes thermal decomposition of organic metal complexes in a high boiling point solvent and in the presence of a surfactant. This approach yields monodisperse highly crystalline NPs and allows for the fine‐tuning of NP size and morphology by controlling several parameters like the solvent nature, kind and concentration of surfactant, aging temperature and reaction time. The typical setup with oleic acid (OA)/oleylamine (OAm) as surfactants can be used to obtain (Zn
In an important report on the synthesis of Fe3O4 and other ferrite NPs, Hyeon
One drawback of the thermal decomposition method is that the as‐synthesized ferrite NPs do not disperse in water due to the hydrophobic surfactant adsorbed onto the surface, which leads to further phase transfer steps. To obtain directly water‐soluble NPs, the groups of Li [29] and Verma [58] introduced a variation in which 4–5 nm Fe and Co ferrites are obtained through the decomposition of metal acetylacetonates in the presence of pyrrolidones that act either as solvents or as hydrophilic stabilizing agents.
3.3. Polyol method
This is a variation of the thermal decomposition in which a given polyol acts as a high‐boiling solvent, reducing and stabilizer agent. Metal precursors are generally organic complexes like acetylacetonates and other carboxylate complexes [65]. Given that the reaction mixture is refluxed at the boiling point of the polyol, changing either the kind or concentration of the polyol leads to different particle
3.4. Hydrothermal and solvothermal synthesis
Hydrothermal methodology consists of the formation of an aqueous (or aqueous‐alcoholic) solution of the metal salts followed by the addition of a base until basic pH is reached. The resulting mixture is then transferred to a pressurized autoclave and subjected to
Solvothermal synthesis can be understood as a modified hydrothermal process where water is replaced by an organic solvent. For instance, n‐octanol along with sodium dodecylbenzenesulfonate has been employed for the preparation of mixed ferrite NPs of Ni and Co with several compositions and varying sizes (7–16 nm), which was tuned as a function of the reaction time [26]. OA can also be used as a steric stabilizer in the reaction mixture using n‐pentanol as a solvent [22]; increasing OA content decreases
4. Functionalization
Surface functionalization of nanostructured ferrites is a crucial step in the design of nanodevices for many applications since proper functionalization determines the final use and allows control over the physico‐chemical processes at the surface, thus tuning several magnetic, optical and electrical properties in the desired direction. Although several synthetic methods allow in situ functionalization of obtained ferrite NPs, this approach is not always enough, and postsynthetic surface functionalization becomes necessary. For example, biomedical and environmental applications require hydrophilic NPs with definite chemical groups. The crucial feature that allows for surface functionalization is the availability of superficial transition metal
There are mainly three approaches to make hydrophilic functional NPs: (i) ligand exchange reaction, (ii) silica coating and (iii) polymer coating. Ligand exchange reactions effectively transfer hydrophobic particles to aqueous medium by the replacement of hydrophobic ligands with hydrophilic ones, without affecting the magnetic core considerably. However, for some applications, magnetic NPs can also be transferred from polar to nonpolar mediums [98, 99]. Small ligands stabilize the NPs mainly by coulombic repulsion of ionized groups, like quaternary ammonium cations and carboxylates [100]; charged groups not only stabilize the magnetic suspension but also reinforce water affinity by facile solvation. Conversely, macromolecular ligands stabilize NPs by interparticle steric repulsions due to extended conformations that they can adopt in contact with good solvents [101]. In cases when the polymer carries ionisable groups, as PAA [34, 93, 101], coulombic repulsions enhance their capabilities as a stabilizer.
Silica coating has the advantage that provides excellent chemical stability to the magnetic core while preventing magnetic interactions, which is traduced into colloidal stability. Following the hydrolysis‐condensation method established by Stöber [102], it is possible to achieve silica shells with controlled thickness by careful addition of tetraethyl orthosilicate (TEOS) to the NP dispersion without the appearance of individual silica particles, which in turn allows for a fine‐tuning of magnetic interactions [103]. Furthermore, silica coating can be functionalized with several organosilanes containing suitable groups like ‐SH [104–106] and ‐NH [105], as depicted in Figure 2.
Two main routes for polymer coating of NPs [107, 108] are: (i) functionalization of the NP surface with a molecule that acts as an initiator for further interfacial‐controlled polymerization [109, 110] and (ii) synthesis of the polymer as the first step followed by surface anchoring [111–114]. The latter is simpler and allows for a wide variety of macromolecules, provided they bear suitable functional groups for surface binding. The former, although more laborious, has the advantage that it is possible to control the surface density of the grafted polymer and the length of the growing chains [115]. A shortcoming concerning macromolecular coating of magnetic NPs emerges when high mass magnetizations are required. Since polymers do not contribute to magnetization, mass magnetization of highly functionalized NPs drops noticeably, and so they might disable the whole system.
Conjugation after primary NP synthesis and water stabilization constitutes the final step prior to environmental and biomedical applications. It affords the ultimate precise chemical functions. Several strategies have been reported to achieve this goal entailing many known organic reactions [107]. For example, Zhao
Coordination reactions like MOF construction have also been developed at ferrite surface. Fe3O4 NPs decorated with carboxyl groups were conjugated with a zeolitic imidazolate framework (ZIF‐8) for the adsorption of contaminants [123, 124]. Such MOF was grown in a step‐by‐step assembly, initiated by the Zn2+ chelation to the oxide surface through carboxyl groups, resulting in a magnetic core surrounded by the ZIF shell. By varying the number of growth cycles, it is possible to tune the thickness of the MOF shell and hence, the interparticle distance between the magnetic cores. Another inorganic reaction at the interface of magnetic NPs reported recently [125] consists of the deposition of hydrous lanthanum oxide over Fe3O4@SiO2 core‐shell NPs simply by adding LaCl3 at basic pH in the presence of the magnetic material. Nanostructures composed of ferrites and noble metals have interesting and promising optical and magnetic properties; the synthesis of such materials can be easily performed by reduction of the corresponding metal salt in the presence of ferrite NPs [126].
In the case of surface thiol‐decorated nanostructures, special care must be taken, since free thiol groups are prone to be oxidized during the synthetic procedures. For example, several papers have reported the oxidation of DMSA and cysteine to disulfide and sulfoxide compounds in the presence of Fe3O4 NPs [24, 127–129]; these undesirable processes not only reduce the effective amount of –SH groups but also could alter magnetite phase. To overcome this drawback, Maurizi
5. Coordination chemistry at the surface
Since the nature of the metal‐ligand interactions at the interface of the ferrites plays a key role in the properties of NPs, efforts have been devoted to unravel the structure and implications of the surface complexes occurring for different types of ligands. For this purpose, spectroscopic techniques like FTIR, XPS, EXAF and XANES are usually employed [22, 24, 58, 122, 131–133]. Mössbauer spectroscopy has also been used since iron spectra are sensitive to spin reorganization after ligand binding and to the kind of iron site that participates in the surface complexes [23, 58, 131].
Specifically, Daou
6. Environmental applications
In this section, we focus on two applications of nanostructured spinel ferrites for environmental remediation technologies in connection with water decontamination: adsorption and oxidation technologies.
6.1. Adsorption technologies for removal of inorganic and organic contaminants
Adsorption is often the most suitable choice for removal of toxic substances in drinking or waste waters, mainly due to its simplicity and high efficiency; the main disadvantage is the sorbent separation after the adsorption process, which can become tedious and energy consuming. However, the use of magnetic materials for adsorption makes the task of sorbent separation easier by allowing magnetic decantation with a permanent magnet. The high surface area of ferrite NPs along with their room temperature superparamagnetism and the great versatility for binding specific functional groups on their surfaces for specific contaminants makes them ideal candidates for the design and development of innovative adsorption strategies. Although several recent reviews covering this subject are available [6, 7, 139, 140], these have generally focused on the thermodynamics and kinetics of the adsorption process and relatively less attention has been paid to unravel the atomic and molecular nature of the interactions occurring at the interface. Although this is a difficult task, this information is crucial for the improvement and optimization of the nanoadsorbent.
6.1.1. Heavy metal cations
Heavy metal cations, found in natural and waste waters resulting from industrial activities, comprise a wide family of hazardous substances with a high impact on human health [141]. Here, we concentrate on those reported studies with a focus on two directions: (i) improving the adsorption capacity and/or selectivity toward a given contaminant by surface functionalization of ferrite NPs and (ii) shedding light on the adsorption mechanism at a molecular and atomic level.
6.1.1.1. Amine‐functionalized nanosystems
Fe3O4 NPs functionalized with several amino‐containing polymers were tested as Cr(VI) and Cu(II) sorbents in aqueous medium [142], showing the increase of adsorption capacity for both cations with the number of –NH moieties in the ligand incorporated to the magnetic nanoplatform. Adsorption and spectroscopic data suggested that metal removal involves coulombic interactions, ion exchange processes and formation of complexes between amine groups and metal ions, although the structure of such complexes was not revealed. Similar results were reported by Huang and Chen [113], in which Fe3O4@PAA NPs decorated with amine groups were proved as a good adsorbent for several heavy metals with positive and negative charges; based on pH studies, authors suggested that cations are adsorbed through chelate complexes while anions are incorporated after ion exchange mechanisms. New insights about Cr(VI) adsorption with an amino‐decorated magnetic sorbent were reported by Zhao
Amino‐functionalized Fe3O4 NPs were tested as a sorbent for Cu(II), Cd(II) and Pb(II) [144]. Adsorption decreased at acid pH values and adsorption capacity for Cu(II) was higher than that for softer Lewis acids Cd(II) and Pb(II). Both results, along with thermodynamic and kinetic data, could indicate the prevalence of coulombic and complexing reactions between surface –NH moieties and the cations. Similar results were presented in other reports [52, 145]. Co‐ferrite NPs coated with a polystyrene shell modified with amino and thioether groups were tested for Hg(II) adsorption [146]. Authors proposed the Hg(II) complexation by these functional groups, followed by partial reduction of Hg(II) to Hg(I), although no proof for this mechanism was presented.
6.1.1.2. Carboxyl‐functionalized nanosystems
Several reports have focused on the adsorption of heavy metal cations by EDTA‐modified magnetic nanosystems in order to take advantage of the high chelating ability of this multifunctional ligand. The key role of EDTA has been confirmed since the adsorption capacity decreases when no EDTA was used in the preparation of the sorbents. Indeed, Ren
6.1.1.3. Thiol and other sulfur‐containing compounds functionalized nanosystems
Fe3O4 NPs functionalized with a polythiolated ligand was probed as Hg(II) adsorbent [118]. XPS studies supported the occurrence of Hg(II)‐S interactions and the simultaneous reduction of Hg(II) to Hg(I) likely at the expense of Fe(II) cations at the surface of the magnetic core. Curiously, no sign of thiol oxidation was encountered. Recently, Wang
Zhu
Fe3O4 NPs functionalized with a copolymer obtained by the partial modification of PAA with thio‐salicyl‐hydrazide were tested for several divalent cations [153]. This system contains both soft (thiol) and hard (carboxyl and amine) moieties, which might explain the good adsorption properties toward soft Cd(II) and hard Co(II) cations. Regarding Pb(II) uptake, XPS studies confirmed the presence of Pb‐S interactions; it is interesting that only one contribution was proposed for the deconvolution of the Pb 4f spectrum, which implies that there is only one coordination environment for Pb(II) cations. The prevalence of Pb‐S interactions is coherent with the small interference effect produced by alkaline/earth metals, since these hard cations largely prefer hard ligands.
Surface ion imprinting techniques can also be used for efficient and selective sequestration of heavy metal cations. Guo
Yantasee
6.1.1.4. Other functional groups and particles with a bare surface
Fe3O4/PAM nanocomposites functionalized with hydroxamic acid moieties were shown to adsorb Pb(II), Cd(II), Co(II) and Ni(II) ions by forming bidentate chelating complexes [116]. The key role of hydroxamic groups was demonstrated, which agrees with the fact that the stability constant of metal‐hydroxamic complexes follows the same order as the maximum adsorption capacity. The structure of these surface complexes was determined from IR and DFT studies and the system was selective toward Pb(II) uptake.
Rutledge
Given that surface magnetite NPs biosynthesized by microorganisms are richer in Fe(II) content with respect to stoichiometric Fe3O4, this biomaterial has been tested for the adsorption and reduction of toxic oxyanions containing Cr(VI) and m99Tc(VII) [85]. Results confirm that bio‐magnetite is a better absorber compared to a commercial magnetite of similar size, and the removal capacity changes with the particular iron substrate that was used for bacteria culture. The adsorption‐reduction mechanism of chromate anions was studied by means of XPS and X‐ray magnetic circular dichroism (XMCD). Authors suggested that after the fast electron transfer reactions between Cr(VI) and surface Fe(II), Cr(III) ions are incorporated into the spinel structure and occupy octahedral interstices, thus forming a layer of ferrimagnetic CrFe2O4 spinel.
6.1.2. Arsenic, phosphorous and fluoride
In a careful spectroscopic study, Liu
Zhang
Another recent report uses Fe3O4@ZIF‐8 as a sorbent [123]. In this case, arsenic adsorption is entirely caused by the ZIF‐8 shell, while magnetite core only acts as a magnetic device to remove the contaminant in a facile and efficient way. Alternatively, magnetite particles encapsulated with calcium alginate were tested as an adsorbent for inorganic and organic As(V) species [159]. The authors found that inorganic species are better adsorbed than monomethyl arsenate. Based on IR and XPS measurements, they suggested that arsenic incorporation likely occurs through the partial reduction of As(V) to As(III) species and the oxidation of both alginate and magnetite. However, spectroscopic studies were not conclusive.
A recent report from Penke
The use of metal hydroxides can be extended to other elements of group V like phosphorus. Thus, Lai
6.1.3. Dyes
Extensive use of organic dyes has become a serious environmental problem since this family of organic compounds is difficult to decompose and transforms to carcinogenic amines. A series of ferrite MFe2O4/rGO (M = Mn2+, Ni2+, Zn2+, Co2+) nanocomposites were tested as combined magnetic materials for adsorption and photocatalytic degradation of Methylene Blue (MB) and Rhodamine B (RhB) under visible light [81] (see Section 6.2). Authors devoted the high adsorption capacity and fast removal rate to the large surface area of the material. For this system, though electrostatic interactions cannot be ruled out, dye retention is mainly caused by the rGO sheets, comprising π‐π stacking interactions between the aromatic moieties of the dyes and the extended π‐conjugated regions in the graphene structure. The same mechanism was claimed earlier using Fe3O4/rGO nanocomposites for MB adsorption [164]; this report also tested other materials like activated carbon and multi‐walled carbon nanotubes (MWCN).
Cobalt ferrites covered by PEG chains were shown to be good adsorbents for several dyes such as methyl orange (MO), MB and Congo red (CR) [75]. Adsorption data indicate that electrostatic interactions are not the prominent cause for adsorption; instead, H‐bonding interactions between –OH groups of PEG and functional groups in the dyes seem to be the responsible cause. The interactions are depicted in Figure 9. H‐bonding has also been claimed as the main interaction of several dyes with naked MnFe2O4 NPs [43].
In a recent work, Dolatkhah and Wilson [114] functionalized Fe3O4 NPs with chitosan grafted with PAA and poly(itaconic) acid (PIA) chains. This polymeric material displays reversible pH‐responsive behavior, which was tested for MB adsorption. As the pH increases, the ionization of the chitosan‐grafted acid groups also increases, favoring the expansion of the grafted chains and the ionic interactions with MB, since this dye is cationic. Hence, adsorption is favored. Afterward, the desorption of MB is accomplished simply by acidification until dye‐sorbent interactions become very weak and the polymeric chains no longer stabilize the colloid, leading to the collapse of the dye‐free NPs. The process is represented in Figure 10.
6.1.4. Aromatic compounds and other organic pollutants
Rodovalho
6.2. Advanced oxidation technology
Advanced oxidation technologies consist of the assisted degradation of a given pollutant by using a source of highly oxidizing transient species. Such species are generally activated by the action of another substance that acts as a catalyst. Since the removal, reuse and toxicity of catalysts are major concerns, investigations have focused on the development of heterogeneous magnetic materials that can activate efficiently the oxidative degradation of the pollutants and at the same time minimize secondary contamination events. Taking into account these requirements, it is not surprising that the growing interest in ferrite NPs is due to the following reasons: (i) large surface area enhances the catalytic activity; (ii) the onset of superparamagnetism enables facile removal of the catalyst; (iii) versatility of ferrite compositions makes feasible the tuning of the optical band gap of the material enabling photo‐degradation approaches and (iv) chemical stability of the ferrite structure avoids metal leaking to the environment.
Nanostructured CoFe2O4 is shown to be a promising material for heterogeneous peroximonosulfate (HSO5−) activation in order to generate sulfate radicals (SO4−
An improvement in the catalytic properties of ferrites can be assessed by using composites with rGO [53, 54, 81] and MWCNs [83]. Such a synergic effect is attributed to the large surface area of the composites and to the electronic properties of these carbon‐based functional materials. The proposed mechanism is outlined below [171]. It comprises the initial formation of the electron‐hole pair in the ferrite phase by photon absorption (I), followed by the rapid electron transfer reaction from the ferrite conduction band to the rGO sheets (II). H2O2 is then decomposed in the vicinity of the rGO producing highly oxidative •OH radicals (III), which are also formed from the remaining holes in the ferrite (IV). As can be seen, step (II) is crucial for the efficient separation of photo‐generated carriers, which is facilitated by the high electron conductivity of the conjugated π structure of the rGO sheets, which inhibits electron‐hole recombination [172]. Moreover, •OH radicals are generated close to the rGO‐adsorbed target organic pollutants, thus enhancing the decomposition rate.
MFe2O4 +
MFe2O4 (
rGO (
MFe2O4 (
Along the same lines, Fu
7. Concluding remarks and perspectives
Synthesis techniques for nanostructured spinel ferrites are available to tune their magnetic properties.
The nanoparticle surface is able to bind a wide variety of molecules with distinct functional groups that not only contribute to colloidal stabilization but also serve as the starting point for further conjugation steps. Many organic and inorganic reactions can be driven at the surface of ferrites, which allow for the tailoring of specific ligands with the desired binding affinity.
The combination of these two advantages—tuning of magnetic properties and surface versatility—makes ferrites useful and promising materials for applications where superparamagnetic behavior is required.
Functionalized ferrite NPs, especially Fe3O4, are useful for removing a wide variety of heavy metals. In the case of cations, amino, carboxyl and thiol functional groups prevail as preferred candidates for metal uptake, although phosphonic and hydroxamic acids constitute promising ligands. Multifunctional ligands (synthetic and natural polymers) contribute to increase the stability and the adsorption capacity of the sorbent. At intermediate pH values, the tendency between metal‐ligand affinities shows that for carboxyl and amino groups, the NPs are more selective toward hard Lewis acids, while for softer ligands like sulfur groups, the tendency is inverted.
For removing arsenic, additional studies are warranted since controversy exists about the structure of the inner‐sphere complexes and the nature of redox reactions at the interface. Also, the use of organic ligands to drive arsenic removal has not been exhausted yet.
Most adsorption studies are limited to thermodynamic and kinetic analysis and the investigations of metal‐binding interactions are supported by phenomenological models. But the mode of coordination and the geometry of the surface complexes are not clear and so detailed spectroscopic studies are still needed. Since this is a tough task due to the inherent difficulties for the achievement of a rigorous surface picture, the use of theoretical calculations could help in this regard.
Organic dyes are preferentially adsorbed by ligand‐decorated magnetic NPs. Composites with functional carbonaceous materials and grafting of smart polymers are promising lines of development.
Spinel ferrites are useful materials for different advanced oxidation technologies, especially as composites with graphene‐based materials due to the electronic and adsorptive properties of these carbon‐based functional materials, which enhance the overall efficiency of the process.
Acknowledgments
The preparation of this chapter was partially supported by the CONACyT (Mexico) Projects 2013‐05‐231461, CB‐2014‐01‐235840 and 2015‐270810.
References
- 1.
Kalia S, Kango S, Kumar A, Haldorai Y, Kumari B, Kumar R. Colloid Polym. Sci. 2014;292(9):2025–2052. - 2.
Wu L, Mendoza‐Garcia A, Li Q, Sun S. Chem. Rev. 2016;116(18):10473–10512. - 3.
Kharisov BI, Dias HVR, Kharissova OV. Arab. J. Chem. 2014. DOI: 10.1016/j.arabjc.2014.10.049. - 4.
Su C. J. Hazard. Journal of hazardous materials. 2017;322(Pt A):48–84. - 5.
Reddy DH, Lee SM. Adv. Colloid Interface Sci. 2013;201–202:68–93. - 6.
Reddy DHK, Yun Y‐S. Coordin. Chem. Rev. 2016;315:90–111. - 7.
Mehta D, Mazumdar S, Singh SK. J. Water Process Eng. 2015;7:244–265. - 8.
Laurent S, Forge D, Port M, Roch A, Robic C, Vander Elst L, Muller RN. Chem. Rev. 2008;108(6):2064–2110. - 9.
Lu AH, Salabas EL, Schüth F. Angew. Chem. Int. Ed. 2007;46(8):1222–1244. - 10.
Mathew DS, Juang R‐S. Chem. Eng. J. 2007;129(1–3):51–65. - 11.
Jang JT, Nah H, Lee JH, Moon SH, Kim MG, Cheon J. Angew. Chem. 2009;48(7):1234–1238. - 12.
Albuquerque AS, Tolentino MVC, Ardisson JD, Moura FCC, De Mendona R, MacEdo WAA. Ceram. Int. 2012;38:2225–2231. - 13.
Tahar LB, Basti H, Herbst F, Smiri LS, Quisefit JP, Yaacoub N, Grenèche JM, Ammar S. Mater. Res. Bull. 2012;47(9):2590–2598. - 14.
Sorensen CM. Magnetism. In: Klabunde KJ, editor. Nanoscale Materials in Chemistry. New York: John Wiley & Sons; 2001. p. 169–221. - 15.
Néel L. Ann. Geophys. 1949;5:99–136. - 16.
Mohapatra J, Mitra A, Bahadur D, Aslam M. Cryst. Eng. Comm. 2013;15(3):524–532. - 17.
Fernandes C, Pereira C, Fernández‐García MP, Pereira AM, Guedes A, Fernández‐Pacheco R, Ibarra A, Ibarra MR, Araújo JP, Freire C. J. Mater. Chem. C. 2014;2(29):5818. - 18.
Artus M, Tahar LB, Herbst F, Smiri L, Villain F, Yaacoub N, Grenèche J‐M, Ammar S, Fiévet F. J. Phys. Condens. Mat. 2011;23:506001. - 19.
Dutta P, Pal S, Seehra MS, Shah N, Huffman GP. J. Appl. Phys. 2009;105:07B501. - 20.
Yuan Y, Rende D, Altan CL, Bucak S, Ozisik R, Borca‐Tasciuc D‐A. Langmuir. 2012;28:13051–13059. - 21.
Costo R, Morales MP, Veintemillas‐Verdaguer S. J. Appl. Phys. 2015;117(6):064311. - 22.
Jovanović S, Spreitzer M, Tramšek M, Trontelj Z, Suvorov D. J. Phys. Chem. C. 2014;118(25):13844–13856. - 23.
Daou TJ, Grenèche JM, Pourroy G, Buathong S, Derory A, Ulhaq‐Bouillet C, Donnio B, Guillon D, Begin‐Colin S. Chem. Mater. 2008;20(18):5869–5875. - 24.
Odio OF, Lartundo‐Rojas L, Santiago‐Jacinto P, Martínez R, Reguera E. J. Phys. Chem. C. 2014;118:2776–2791. - 25.
Aslibeiki B, Kameli P, Ehsani MH, Salamati H, Muscas G, Agostinelli E, Foglietti V, Casciardi S, Peddis D. J. Magn. Magn. Mater. 2016;399:236–244. - 26.
Jia X, Chen D, Jiao X, He T, Wang H, Jiang W. J. Phys. Chem. C. 2008;112(4):911–917. - 27.
Topkaya R, Kurtan U, Baykal A, Toprak MS. Ceram. Int. 2013;39(5):5651–5658. - 28.
Vestal CR, Zhang ZJ. J. Am. Chem. Soc. 2003;125:9828–9833. - 29.
Li Z, Chen H, Bao H, Gao M. Chem. Mater. 2004;16(8):1391–1393. - 30.
Vestal CR, Zhang ZJ. Nano Lett. 2003;3:1739–1743. - 31.
Batlle X, Pérez N, Guardia P, Iglesias O, Labarta A, Bartolomé F, García L, Bartolomé J, Roca A, Morales M. J. Appl. Phys. 2011;109(7):07B524-1–07B524-6. - 32.
Pereira AM, Pereira C, Silva AS, Schmool DS, Freire C, Grenèche J‐M, Araújo JP. J. Appl. Phys. 2011;109(11):114319–114324. - 33.
Yang H, Hasegawa D, Takahashi M, Ogawa T. Appl. Phys. Lett. 2009;94(1):013103-1–013103-3. - 34.
Odio OF, Lartundo‐Rojas L, Palacios EG, Martínez R, Reguera E. Appl. Surf. Sci. 2016;386:160–177. - 35.
Bishop KJ, Wilmer CE, Soh S, Grzybowski BA. Small. 2009;5(14):1600–1630. - 36.
Peddis D, Cannas C, Musinu A, Ardu A, Orrù F, Fiorani D, Laureti S, Rinaldi D, Muscas G, Concas G, Piccaluga G. Chem. Mater. 2013;25:2–10. - 37.
Dormann JL, Fiorani D, Tronc E. J. Magn. Magn. Mater. 1999;202:251–267. - 38.
Tholence JL, Solid St. Commun. 1980;35(2):113–117. - 39.
Shtrikman S, Wohlfarth EP, Phys. Lett. 1981;85(8–9):467–470. - 40.
Singh V, Seehra MS, Bonevich J, J. Appl. Phys. 2009;105(7): 07B518. - 41.
Dormann JL, Bessais L, Fiorani D, J. Phys. C. 1998;21(10):2015–2034. - 42.
Seehra MS, Pisane KL, J. Phys. Chem. Solids. 2016;93:79–81. - 43.
Yang L, Zhang Y, Liu X, Jiang X, Zhang Z, Zhang T, Zhang L. Chem. Eng. J. 2014;246:88–96. - 44.
Roonasi P, Nezhad AY. Mater. Chem. Phys. 2015;172:143–149. - 45.
Massart R, Cabuil V. J. Chim. Phys. PCB. 1987;84(7–8):967–973. - 46.
Mascolo M, Pei Y, Ring T. Materials. 2013;6(12):5549–5567. - 47.
Vadivel M, Babu RR, Arivanandhan M, Ramamurthi K, Hayakawa Y. RSC Adv. 2015;5(34):27060–27068. - 48.
Krishna Surendra M, Annapoorani S, Ansar EB, Harikrishna Varma PR, Ramachandra Rao MS. J. Nanopart. Res. 2014;16(12):2773. - 49.
Zhang Y, Nan Z. Mater. Lett. 2015;149:22–24. - 50.
Anirudhan T, Shainy F. J. Ind. Eng. Chem. 2015;32:157–166. - 51.
Garza‐Navarro MA, Torres‐Castro A, García‐Gutiérrez DI, Ortiz‐Rivera L, Wang YC, González‐González VA. J. Phys. Chem. C. 2010;114(41):17574–17579. - 52.
Tran HV, Tran LD, Nguyen TN. Mater. Sci. Eng.: C. 2010;30(2):304–310. - 53.
Yao Y, Yang Z, Zhang D, Peng W, Sun H, Wang S. Ind. Eng. Chem. Res. 2012;51:6044–6051. - 54.
Yao Y, Cai Y, Lu F, Wei F, Wang X, Wang S. J. Hazard. Mater. 2014;270:61–70. - 55.
Lingamdinne LP, Choi Y‐L, Kim I‐S, Chang Y‐Y, Koduru JR, Yang J‐K. RSC Adv. 2016;6:73776–73789. - 56.
Pereira C, Pereira AM, Fernandes C, Rocha M, Mendes R, Fernández‐García MP, Guedes A, Tavares PB, Grenèche J‐M, Araújo JP, Freire C. Chem. Mater. 2012;24(8):1496–1504. - 57.
Zhang Y, Shi Q, Schliesser J, Woodfield BF, Nan Z. Inorg. Chem. 2014;53(19):10463–10470. - 58.
Verma S, Pravarthana D. Langmuir. 2011;27(21):13189–13197. - 59.
Park J, An K, Hwang Y, Park JG, Noh HJ, Kim JY, Park JH, Hwang NM, Hyeon T. Nat. Mater. 2004;3(12):891–895. - 60.
Park J, Lee E, Hwang NM, Kang M, Kim SC, Hwang Y, Park JG, Noh HJ, Kim JY, Park JH. Angew. Chem. 2005;117(19):2932–2937. - 61.
Sun S, Zeng H, Robinson DB, Raoux S, Rice PM, Wang SX, Li G. J. Am. Chem. Soc. 2004;126(1):273–279. - 62.
Yang C, Wu J, Hou Y. Chem. Comm. 2011;47(18):5130–5141. - 63.
Silvestri A, Mondini S, Marelli M, Pifferi V, Falciola L, Ponti A, Ferretti AM, Polito L. Langmuir. 2016;32(28):7117–7126. - 64.
Moriya M, Ito M, Sakamoto W, Yogo T. Cryst. Growth Des. 2009;9(4):1889–1893. - 65.
Mondini S, Cenedese S, Marinoni G, Molteni G, Santo N, Bianchi CL, Ponti A. J. Colloid Interface Sci. 2008;322(1):173–179. - 66.
Cai W, Wan J. J. Colloid Interface Sci. 2007;305(2):366–370. - 67.
Zhang B, Tu Z, Zhao F, Wang J. Appl. Surf. Sci. 2013;266:375–379. - 68.
Maity D, Chandrasekharan P, Si‐Shen F, Xue J‐M, Ding J. J. Appl. Phys. 2010;107(9):09B310. - 69.
Maity D, Kale SN, Kaul‐Ghanekar R, Xue J‐M, Ding J. J. Magn. Magn. Mater. 2009;321(19):3093–3098. - 70.
Deligöz H, Baykal A, Tanrıverdi EE, Durmus Z, Toprak MS. Mater. Res. Bull. 2012;47(3):537–543. - 71.
Gonçalves RH, Cardoso CA, Leite ER. J Mater Chem. 2010;20(6):1167–1172. - 72.
Zhang C, Sui J, Li J, Tang Y, Cai W. Chem. Eng. J. 2012;210:45–52. - 73.
Baldi G, Bonacchi D, Franchini MC, Gentili D, Lorenzi G, Ricci A, Ravagli C. Langmuir. 2007;23(7):4026–4028. - 74.
Ji GB, Tang SL, Ren SK, Zhang FM, Gu BX, Du YW. J. Cryst. Growth. 2004;270(1–2):156–161. - 75.
Wu X, Wang W, Li F, Khaimanov S, Tsidaeva N, Lahoubi M. Appl. Surf. Sci. 2016;389:1003–1011. - 76.
Zong M, Huang Y, Ding X, Zhang N, Qu C, Wang Y. Ceram. Int. 2014;40(5):6821–6828. - 77.
Meidanchi A, Akhavan O. Carbon. 2014;69:230–238. - 78.
Rahman MM, Khan SB, Faisal M, Asiri AM, Alamry KA. Sensors Actuators B. 2012;171–172:932–937. - 79.
Komarneni S, D'Arrigo MC, Leonelli C, Pellacani GC, Katsuki H. J. Am. Ceram. Soc. 1998;81(11):3041–3043. - 80.
Bastami TR, Entezari MH, Kwong C, Qiao S. Front. Chem. Sci. Eng. 2014;8(3):378–385. - 81.
Bai S, Shen X, Zhong X, Liu Y, Zhu G, Xu X, Chen K. Carbon. 2012;50:2337–2346. - 82.
Ding Y, Zhu L, Wang N, Tang H. Appl. Catal. B. 2013;129:153–162. - 83.
Zhang X, Feng M, Qu R, Liu H, Wang L, Wang Z. Chem. Eng. J. 2016;301:1–11. - 84.
Aubery C, Solans C, Sanchez‐Dominguez M. Langmuir. 2011;27(23):14005–14013. - 85.
Cutting RS, Coker VS, Telling ND, Kimber RL, Pearce CI, Ellis BL, Lawson RS, van der Laan G, Pattrick RAD, Vaughan DJ, Arenholz E, Lloyd JR. Environ. Sci. Technol. 2010;44(7):2577–2584. - 86.
McCormick ML, Adriaens P. Environ. Sci. Technol. 2004;38(4):1045–1053. - 87.
Kikukawa N, Takemori M, Nagano Y, Sugasawa M, Kobayashi S. J. Magn. Magn. Mater. 2004;284:206–214. - 88.
Choodamani C, Nagabhushana GP, Ashoka S, Daruka Prasad B, Rudraswamy B, Chandrappa GT. J. Alloys Compd. 2013;578:103–109. - 89.
Liu B, Li Q, Zhang B, Cui Y, Chen H, Chen G, Tang D. Nanoscale. 2011;3(5):2220–2226. - 90.
Marin T, Montoya P, Arnache O, Calderon J. J. Phys. Chem. B. 2016;120(27):6634–6645. - 91.
Bellusci M, Aliotta C, Fiorani D, La Barbera A, Padella F, Peddis D, Pilloni M, Secci D. J. Nanopart. Res. 2012;14(6):904. - 92.
Duan H, Kuang M, Wang X, Wang YA, Mao H, Nie S. J. Phys. Chem. C. 2008;112(22):8127–8131. - 93.
Dai Q, Lam M, Swanson S, Yu RH, Milliron DJ, Topuria T, Jubert PO, Nelson A. Langmuir. 2010;26(22):17546–17551. - 94.
Marcelo G, Pérez E, Corrales T, Peinado C. J. Phys. Chem. C. 2011;115(51):25247–25256. - 95.
Tombácz E, Tóth IY, Nesztor D, Illés E, Hajdú A, Szekeres M, Vékás L. Colloids Surf. A. 2013;435:91–96. - 96.
Cheng K, Peng S, Xu C, Sun S. J. Am. Chem. Soc. 2009;131(30):10637–10644. - 97.
Das M, Mishra D, Maiti TK, Basak A, Pramanik P. Nanotechnology. 2008;19(41):415101. - 98.
Rodovalho FL, Capistrano G, Gomes JA, Sodré FF, Chaker JA, Campos AFC, Bakuzis AF, Sousa MH. Chem. Eng. J. 2016;302:725–732. - 99.
Dong A, Ye X, Chen J, Kang Y, Gordon T, Kikkawa JM, Murray CB. J. Am. Chem. Soc. 2010;133(4):998–1006. - 100.
Wu Y, Guo J, Yang W, Wang C, Fu S. Polymer. 2006;47(15):5287–5294. - 101.
Ge J, Hu Y, Biasini M, Dong C, Guo J, Beyermann WP, Yin Y. Chemistry. 2007;13(25):7153–7161. - 102.
Stöber W, Fink A, Bohn E. J. Colloid Interface Sci. 1968;26(1):62–69. - 103.
Graf C, Vossen DLJ, Imhof A, van Blaaderen A. Langmuir. 2003;19(17):6693–6700. - 104.
Gill CS, Price BA, Jones CW. J. Catal. 2007;251:145–152. - 105.
Rocha M, Fernandes C, Pereira C, Rebelo SLH, Pereira MFR, Freire C. RSC Adv. 2015;5:5131–5141. - 106.
Li G, Zhao Z, Liu J, Jiang G. J. Hazard. Mater. 2011;192(1):277–283. - 107.
Lattuada M, Hatton TA. Langmuir. 2007; 23(4):2158–2168. - 108.
Hood M, Mari M, Muñoz‐Espí R. Materials. 2014;7(5):4057–4087. - 109.
Gelbrich T, Feyen M, Schmidt AM. Macromolecules. 2006;39(9):3469–3472. - 110.
Sun Y, Ding X, Zheng Z, Cheng X, Hu X, Peng Y. Eur. Polym. J. 2007;43(3):762–772. - 111.
Li G‐Y, Huang K‐L, Jiang Y‐R, Ding P, Yang D‐L. Biochem. Eng. J. 2008;40(3):408–414. - 112.
Zhang T, Ge J, Hu Y, Yin Y. Nano Lett. 2007;7(10):3203–3207. - 113.
Huang SH, Chen DH. J. Hazard. Mater. 2009;163(1):174–179. - 114.
Dolatkhah A, Wilson LD. ACS Appl. Mater. Interfaces. 2016;8(8):5595–5607. - 115.
Wu W, He Q, Jiang C. Nanoscale Res. Lett. 2008;3(11):397–415. - 116.
Zhao F, Tang WZ, Zhao D, Meng Y, Yin D, Sillanpää M. J. Water Proc. Eng. 2014;4:47–57. - 117.
Zhao YG, Shen HY, Pan SD, Hu MQ. J. Hazard. Mater. 2010;182(1–3):295–302. - 118.
Pan S, Shen H, Xu Q, Luo J, Hu M. J. Colloid Interface Sci. 2012;365(1):204–212. - 119.
Ren Y, Abbood HA, He F, Peng H, Huang K. Chem. Eng. J. 2013;226:300–311. - 120.
Ge F, Li MM, Ye H, Zhao BX. J. Hazard. Mater. 2012;211–212:366–372. - 121.
Zhu Y, Hu J, Wang J. J. Hazard. Mater. 2012;221–222:155–161. - 122.
Rutledge RD, Warner CL, Pittman JW, Addleman RS, Engelhard M, Chouyyok W, Warner MG. Langmuir. 2010;26(14):12285–12292. - 123.
Zou Z, Wang S, Jia J, Xu F, Long Z, Hou X. Microchem. J. 2016;124:578–583. - 124.
Zheng J, Cheng C, Fang W‐J, Chen C, Yan R‐W, Huai H‐X, Wang C‐C. Cryst. Eng. Comm. 2014;16(19):3960. - 125.
Lai L, Xie Q, Chi L, Gu W, Wu D. J. Colloid Interface Sci. 2016;465:76–82. - 126.
Xu Z, Hou Y, Sun S. J. Am. Chem. Soc. 2007;129(28):8698–8699. - 127.
Dolci S, Ierardi V, Remskar M, Jagličić Z, Pineider F, Boni A, Pampaloni G, Veracini CA, Domenici V. J. Mater. Sci. 2013;48(3):1283–1291. - 128.
Nishio K, Gokon N, Tsubouchi S, Ikeda M, Narimatsu H, Sakamoto S, Izumi Y, Abe M, Handa H. Chem. Lett. 2006;35(8):974–975. - 129.
Soler MA, Lima EC, Nunes ES, Silva FL, Oliveira AC, Azevedo RB, Morais PC. J. Phys. Chem. A. 2011;115(6):1003–1008. - 130.
Maurizi L, Bisht H, Bouyer F, Millot N. Langmuir. 2009;25(16):8857–8859. - 131.
Daou TJ, Begin‐Colin S, Grenèche JM, Thomas F, Derory A, Bernhardt P, Legaré P, Pourroy G. Chem. Mater. 2007;19(18):4494–4505. - 132.
Hatakeyama M, Kishi H, Kita Y, Imai K, Nishio K, Karasawa S, Masaike Y, Sakamoto S, Sandhu A, Tanimoto A, Gomi T, Kohda E, Abe M, Handa H. J. Mater. Chem. 2011;21(16):5959. - 133.
Wilson D, Langell MA. Appl. Surf. Sci. 2014;303:6–13. - 134.
Palchoudhury S, An W, Xu Y, Qin Y, Zhang Z, Chopra N, Holler RA, Turner CH, Bao Y. Nano Lett. 2011;11(3):1141–1146. - 135.
Rath SS, Sinha N, Sahoo H, Das B, Mishra BK. Appl. Surf. Sci. 2014;295:115–122. - 136.
Lin CL, Lee CF, Chiu WY. J. Colloid Interface Sci. 2005;291(2):411–420. - 137.
Aslam M, Schultz EA, Sun T, Meade T, Dravid VP. Cryst. Growth Des. 2007;7(3):471–475. - 138.
Sathish S, Balakumar S. Mater. Chem. Phys. 2016;173:364–371. - 139.
Hua M, Zhang S, Pan B, Zhang W, Lv L, Zhang Q. J. Hazard. Mater. 2012;211–212:317–331. - 140.
Gómez‐Pastora J, Bringas E, Ortiz I. Chem. Eng. J. 2014;256:187–204. - 141.
Järup L. Br. Med. Bull. 2003;68(1):167–182. - 142.
Shen H, Pan S, Zhang Y, Huang X, Gong H. Chem. Eng. J. 2012;183:180–191. - 143.
Zhao D, Gao X, Wu C, Xie R, Feng S, Chen C. Appl. Surf. Sci. 2016;384:1–9. - 144.
Xin X, Wei Q, Yang J, Yan L, Feng R, Chen G, Du B, Li H. Chem. Eng. J. 2012;184:132–140. - 145.
Tan Y, Chen M, Hao Y. Chem. Eng. J. 2012;191:104–111. - 146.
Jainae K, Sukpirom N, Fuangswasdi S, Unob F. J. Ind. Eng. Chem. 2015;23:273–278. - 147.
Zhao F, Repo E, Sillanpää M, Meng Y, Yin D, Tang WZ. Ind. Eng. Chem. Res. 2015;54:1271–1281. - 148.
Liu Y, Fu R, Sun Y, Zhou X, Baig SA, Xu X. Appl. Surf. Sci. 2016;369:267–276. - 149.
Mahdavian AR, Mirrahimi MA‐S. Chem. Eng. J. 2010;159(1–3):264–271. - 150.
Wang H, Chen QW, Chen J, Yu BX, Hu XY. Nanoscale. 2011;3(11):4600–4603. - 151.
Wang Z, Xu J, Hu Y, Zhao H, Zhou J, Liu Y, Lou Z, Xu X. J. Taiwan Inst. Chem. Eng. 2016;60:394–402. - 152.
Viltužnik B, Košak A, Zub YL, Lobnik A. J. Sol‐Gel Sci. Technol. 2013;68(3):365–373. - 153.
Zargoosh K, Abedini H, Abdolmaleki A, Molavian MR. Ind. Eng. Chem. Res. 2013;52:14944–14954. - 154.
Guo B, Deng F, Zhao Y, Luo X, Luo S, Au C. Appl. Surf. Sci. 2014;292:438–446. - 155.
Yantasee W, Warner CL, Sangvanich T, Addleman RS, Carter TG, Wiacek RJ, Fryxell GE, Timchalk C, Warner MG. Environ. Sci. Technol. 2007;41:5114–5119. - 156.
Claudio ES, Godwin HA, Magyar JS. Fundamental Coordination Chemistry, Environmental Chemistry, and Biochemistry of Lead(II). In: Karlin KD, editor. Progress in Inorganic Chemistry, Volume 51. New York: John Wiley & Sons; 2003. p. 1–144. - 157.
Liu C‐H, Chuang Y‐H, Chen T‐Y, Tian Y, Li H, Wang M‐K, Zhang W. Environ. Sci. Technol. 2015;49(13):7726–7734. - 158.
Su C, Puls RW. Water Air Soil Poll. 2008;193(1–4):65–78. - 159.
Lim SF, Zheng YM, Chen JP. Langmuir. 2009;25(9):4973–4978. - 160.
Zhang S, Li XY, Chen JP. J. Colloid Interface Sci. 2010;343(1):232–238. - 161.
Penke YK, Anantharaman G, Ramkumar J, Kar KK. RSC Adv. 2016;6:55608–55617. - 162.
Peng B, Song T, Wang T, Chai L, Yang W, Li X, Li C, Wang H. Chem. Eng. J. 2016;299:15–22. - 163.
Bhaumik M, Leswifi TY, Maity A, Srinivasu VV, Onyango MS. J. Hazard. Mater. 2011;186(1):150–159. - 164.
Ai L, Zhang C, Chen Z. J. Hazard. Mater. 2011;192(3):1515–1524. - 165.
Ou J, Mei M, Xu X. J. Solid State Chem. 2016;238:182–188. - 166.
Zhang S, Dong Y, Yang Z, Yang W, Wu J, Dong C. Chem. Eng. J. 2016;304:325–334. - 167.
Yang Q, Choi H, Al‐Abed SR, Dionysiou DD. Appl. Catal. B. 2009;88:462–469. - 168.
Guan YH, Ma J, Ren YM, Liu YL, Xiao JY, Lin Lq, Zhang C. Water Res. 2013;47:5431–5438. - 169.
Zhang T, Zhu H, Croué J‐P. Environ. Sci. Technol. 2013;47(6):2784–2791. - 170.
Yan J, Lei M, Zhu L, Anjum MN, Zou J, Tang H. J. Hazard. Mater. 2011;186:1398–1404. - 171.
Jumeri FA, Lim HN, Ariffin SN, Huang NM, Teo PS, Fatin SO, Chia CH, Harrison I. Ceram. Int. 2014;40:7057–7065. - 172.
Fu Y, Chen H, Sun X, Wang X. Appl. Catal. B. 2012;111–112:280–287. - 173.
Haw C, Chiu W, Abdul Rahman S, Khiew P, Radiman S, Abdul Shukor R, Hamid MAA, Ghazali N. New J. Chem. 2016;40:1124–1136.