Design and Development of g-C3N4/ZnO/CdS Ternary Photocatalyst for the Removal of Environmentally Hazardous Organic Dyes under Visible Light

The processing of wastewater has emerged as a primary focus of research owing to the unavailability of clean water to satisfy the current population’s needs. In this work, a ternary nano-photocatalyst, g-C3N4/ZnO/CdS exhibiting visible light activity has been fabricated via a dual-step process that involved a pyrolytic transformation of urea to g-C3N4 subsequently followed by the solid state mechanochemical method to fabricate g-C3N4/ZnO/CdS. The synthesized nanomaterial underwent characterization using advanced techniques such as XRD, FTIR, FE-SEM/EDAX and UV-DRS techniques. The decomposition of Indigo Carmine dye was performed under the illumination of visible light, resulting in 99.6% degradation using a 50-mg photocatalytic dosage. Kinetic studies indicate that the photodegradation process followed pseudo-first-order where the phenomenon of adsorption adhered to the Langmuir–Hinshelwood model. This work attempted the generation of a multi pathway of electron migration by combining more than one Type-II heterojunction, which can effectively delay the electron-carrier recombination.