Chapters authored
Photocatalytic Applications of Titanium Dioxide (TiO2)
Water pollution is one the fundamental problems that have got the serious concerns of the researchers. Water poluution arises due to a number of reasons including domestic, industrial, agricultural, scinec and technology. The textile industry is the main industry that releases the dyes contaminated wastewater to the environment. A varities of protocols have been attempeted for the removal of dyes from aqueous body. Photocatalysis is one of the effective techniques which offer opportunities to overcome the aqueous pollution caused by rapid industrialization and urbanization. The semiconductor metal oxides used as photocatalysts are capable to provide a sustainable and clean ecosystem due to the tunable physiochemical characteristics of semiconductor metal oxides. Titanium dioxide (TiO2) is one of the metal oxides that can be effectively employed as a photocatalyst in the abatement of aqueous pollution due to organic compounds. The catalytic performance of titanium dioxide depends on several parameters like its crystallinity, surface area, and morphology. Titanium dioxide has shown good performance in the different photocatalytic systems, however, the characteristics like wide band gap and low conductivity limit the photocatalytic performance of titanium dioxide. Various attempts have been made to improve the photocatalytic performance of titanium dioxide. Herein, we summarize the various attempts to improve the photocatalytic performance of titanium dioxide in the abatement of aqueous pollution. The attempts made for the improvement of photocatalytic performance of titanium dioxide include modifications in composition, doping of other metal, and formation of heterojunctions with other metal oxides.
Part of the book: Titanium Dioxide
Chemistry and Modern Techniques of Characterization of Co-Crystals
Co-crystals are multicomponent molecular materials held together through non-covalent interactions that have recently attracted the attention of supramolecular scientists. They are the monophasic homogeneous materials where a naturally occurring pharmaceutical active ingredient (API) and a pharmaceutically acceptable co-crystal former are bonded together in a 1:1 via non-covalent forces such as H-bonds, π–π, and van der Waals forces. Co-crystallization is a promising research field, especially for the pharmaceutical industry, due to the enormous potential of improved solubility and bioavailability. Co-crystals are not the only multicomponent molecular materials, as there are many other forms of multicomponent molecular solids such as salts, hydrates, solvates, and eutectics. The formation of co-crystals can roughly be predicted by the value of ∆pKa, that is, if the ∆pKa is more than 3, then this monophasic homogeneous material usually falls in the category of salts, whereas if the ∆pKa is less than 2, then co-crystals are usually observed. A number of methods are available for the co-crystal formation, broadly classified into two classes established on state of formation, that is, solution-based and solid-based co-crystal formation. Similarly, a number of techniques are available for the characterization of co-crystals such as Fourier transforms-infrared spectroscopy, single-crystal and powder X-ray diffraction, etc. In this chapter, we will discuss the available methods for co-crystallization and its characterization.
Part of the book: Drug Formulation Design