Application of Nanocomposites for Photocatalytic Removal of Dye Contaminants

The application of semiconductor nanocomposites for photocatalytic dye degradation experiments are described in this chapter. Using nanocomposites is one of the principal methods to tune the physicochemical properties of a photocatalyst. Sol-gel, hydrothermal, and precipitation techniques are commonly applied to fabricate the nanocomposites. Most of the research work for the degradation of various organic dyes has been performed with titania (TiO₂), zinc oxide (ZnO), and graphitic carbon nitride (g-C₃N₄). The active surface area for dye degradation is higher in nanocomposites when compared to the single-phase nanomaterials. The lifetime of charge carriers is extended and the electron-hole separation is highly enhanced by adding a narrow band gap semiconductor or suitable support (carbon, polymer, zeolite, clay, etc.). The mineralization of dye molecules has been studied by chemical oxygen demand (COD) and total organic carbon (TOC) analysis. The mechanisms and the important key findings about nanocomposites reported in the last five years are also discussed in this chapter.