Boosted photocatalytic elimination toward Cr(VI) and organic pollutants over BUC-21/Cd0.5Zn0.5S under LED visible Light

Series BUC-21/Cd0.5Zn0.5S (B100CX, X = 20, 60, 100) were prepared by simply ball-milling the mixture of BUC-21/Cd0.5Zn0.5S at 30 HZ for 20 min. The photocatalytic activities of B100CX under the illuminance of low power LED visible light were estimated. According to influencing factor experiments, it was revealed that B100CX composites displayed better Cr(VI) sequestration performances than pristine BUC-21 and individual Cd0.5Zn0.5S, resulting from the effective separation of photo-induced electron-hole pairs and the inhibited aggregation of the Cd0.5Zn0.5S nano-particles. The photoluminescence, electrochemical analysis, active species trapping experiments and electron spin resonance (ESR) provided further evidence for improved photocatalytic activity. After three cycles, the photocatalytic Cr(VI) sequestration efficiency over B100C100 was still more than 90%, implying that B100C100 displayed remarkable recyclability and stability. At last, the corresponding photocatalytic mechanism over B100CX was proposed and verified by some techniques.