Constructing CoWO 4 /Cd 0.5 Zn 0.5 S Heterojunction for Enhanced Visible Light Driven Photocatalytic Degradation of Organic Pollutants

Abstract The ecosystems and human health have been gravely impacted by growing organic pollutants and photocatalysis and is regarded as one of the most valid and green governance approaches. Herein, a novel type II CoWO 4 /Cd 0.5 Zn 0.5 S (CWO/CZS) heterojunction photocatalyst was constructed by a secondary hydrothermal method and applied to the photodegradation of rhodamine B (RhB) and methyl orange (MO). The experimental results show that the CWO/CZS heterojunction photocatalyst exhibits excellent photodegradation activity toward RhB and MO under visible light irradiation. CWO/CZS (0.10:1) achieved a degradation efficiency of 96.7% for RhB within 15 min and the apparent rate constants were 135 and 5 times of CWO and CZS, respectively. The high photodegradation rate of MO also demonstrates its excellent photocatalytic activity. The significant improvement in the photocatalytic degradation rate originated from the expansion of visible light absorption and dense interfacial contact between the nanoparticles, which could effectively accelerate the transfer of photogenerated charges. This work demonstrates a novel type II heterojunction photocatalyst for the effective removal of organic dyes, providing fresh ideas for wastewater purification.