This chapter elaborates a review of sol-gel–prepared TiO2 photocatalyst for different photocatalytic applications. Among the semiconductors employed, TiO2 is known as an attractive photocatalyst owing to its high photosensitivity, nontoxicity, easy availability, strong oxidizing power and long-term stability. Some research works related to the effect of sol-gel preparation parameters on physicochemical properties and different photocatalytic applications of prepared TiO2 photocatalysts are reported. Furthermore, various sol-gel and related systems for modification of TiO2 photocatalytic performance, including transition metals and co-doing of TiO2, were considered. The results illustrated that doping TiO2 with metal ions through sol-gel method usually resulted in an improved efficiency of TiO2 photocatalyst. This method has all the advantages over other preparation techniques in terms of purity, homogeneity, felicity and flexibility in introducing dopants in a large concentration, stoichiometry control, ease of processing and composition control.
Part of the book: Recent Applications in Sol-Gel Synthesis
One-dimensional (1D) TiO2 nanostructures (e.g., nanotubes, nanobelts, nanowires, and nanorods) have been considered to be very attractive candidates for various applications including photocatalytic degradation of pollutants, photocatalytic CO2 reduction into energy fuels, water splitting, solar cells, supercapacitors, and lithium-ion batteries. More importantly, the dimensionality associated with zero-dimensional TiO2 nanostructures gives unique physical properties, including a high aspect ratio structure, chemical stability, excellent electronic or ionic charge transfer, and a specific interface effect. This chapter elaborates on crystal structure and properties, preparation techniques, strategies for improving photocatalytic activity of 1D-TiO2 nanostructure and its applications. Amongst all preparation techniques, the influence of experimental parameters on morphologies of 1D-TiO2 nanostructure using hydro/solvothermal method is extensively explained. Furthermore, some critical engineering strategies to enhance the properties of 1D-TiO2 nanostructures like increasing the surface area, extending the light absorption, and efficient separation of electrons/holes that advantage their potential applications are described. Moreover, a brief summary of their environmental and energy applications is provided.
Part of the book: Titanium Dioxide