Fabrication of g-C3N4/CuS heterojunction: A potential Z scheme photocatalyst for dye degradation in aqueous media under direct sunlight illumination

Abstract

An eco-friendly method of treating contaminated water is the photocatalytic elimination of organic contaminants. The g-C3N4/CuS (CS) binary hetero-structured composites were successfully synthesized in this study using an easy in-situ hydrothermal technique. The synthesis of CS heterojunction catalysts is successfully confirmed by the FT-IR, powder XRD, FE-SEM, EDX, TEM, HR-TEM, UV-Vis DRS, high-resolution XPS, BET, and PL spectrum analysis. In comparison to pure g-C3N4 and CuS, the CS heterojunction composite materials exhibit boosted photocatalytic performance under direct sunlight for the breakdown of different organic dyes. The CS-10 (g-C3N4/10 %CuS) composite eliminated 97.9 % MO and 96 % MB dye after 70 min and 80 min of direct sunlight irradiation, respectively. After the five successive recycle tests, there was no discernible decrease in photoactivity. Increased photocatalytic action may be credited to the effective separation of photo-produced electron-hole (e--h+) pairs as a consequence of the e--h+ migration between g-C3N4 and CuS via the Z-scheme heterojunction mechanism; as a result, there is more e--h+ accessible for the photocatalytic process. The findings of the experiments reveal that photo-produced holes (h+) and superoxide radicals (•O2–) are the major species actively involved in dye elimination, whereas hydroxyl radicals (•OH) are just a minor contributor to photocatalytic activity.