Heterostructured transition metal chalcogenides photocatalysts for organic contaminants degradation

Pharmaceuticals, pesticides, herbicides, fertilizers, phenols, detergents, surfactants, and dyes form a large group of organic contaminants that are emitted from various sources and pose severe ecological problems. These contaminants are generally released from industrial processes. Recently the COVID-19 pandemic compelled people the intake antibiotics, which eventually elevate the accumulation of pharmaceutical waste in the environment matrix. Therefore, several heterogeneous photocatalysts have been developed for the efficient degradation of pharmaceuticals in water. Among these high-performance heterostructure metals, chalcogenides have been extensively used these days due to their promising properties such as direct to indirect bandgap transition and elemental composition, catalytic stability, activity in visible light, and optoelectrical properties. In this chapter, we have discussed the different synthesis techniques, their physicochemical characterization, and their application for the photocatalytic degradation of organic contaminants. In heterostructure metal chalcogenides, we have covered transition metals (Ti, W, Nb, V, and Mn), nontransition metals (Zn, Cd, Bi, and Sb), semiconductors (Mo, Ti, and W), and chalcogenides include oxides, sulfides, selenides, and tellurides. The synthesis of heterostructure metal chalcogenide photocatalysts involves hot plate, single pot, solvothermal, hydrothermal, and electrospinning techniques. More importantly, their electronic and optoelectronic properties can be flexibly regulated via the layer stacking order, composition, and layer number/thickness without requiring stringent lattice matching.