Efficient photocatalytic reduction of Cr(VI) in aqueous solution over CoS2/g-C3N4-rGO nanocomposites under visible light

There is an increasingly significant issue on Cr(VI) pollution in chemical industry and environmental protection. In this study, we have successfully synthesized CoS2/g-C3N4-rGO hybrid nanocomposites via a simple one-pot solvothermal method as an effective photocatalyst. The CoS2/g-C(3)N(4 )heterostructure on rGO showed improved photocatalytic performance for Cr(VI) reduction during visible light irradiation. The optimized photocatalyst shows the 99.8% reduction efficiency for Cr(VI) within 120 min at pH = 2 and still exhibits more than 98% removal efficiency after 5 cycles at the same condition. The enhanced photocatalytic performance of the hybrid nanocomposites can be assigned to the enhanced utilization of visible light arising from the coupling effect in the hybrid nanocomposites and more effective electron-hole pairs separation in heterostructure junction, and large specific surface area and more exposing active sites of CoS2 dispersed on rGO. This study provides a new method to develop high-efficiency photocatalysts for Cr(VI) removal.