ZnS:Cu powders with strong visible-light photocatalysis and pyro-catalysis for room-temperature dye decomposition

In this work, strong visible-light photocatalysis and pyro-catalysis for dye decomposition was observed in hexagonal wurtzite phase ZnS:Cu. As described herein, ZnS:Cu ceramic is shown to be a visible-light-responsive material with a band gap of ~2.77 eV. Under visible-light irradiation, the photocatalytic decomposition ratios of ZnS:Cu on 5 mg/L Rhodamine B, methylene blue, and acid orange 7 solutions reach 99.2%, 95.9%, and 78.8%, respectively. With respect to pyro-catalysis results, the decomposition ratio for acid orange 7 in the same concentration is 82.2%. For photo-/pyro-bi-catalysis, the decomposition ratio can reach ~95%. In summary, the ZnS:Cu ceramics exhibit strong visible-light photocatalysis and pyro-catalysis, making it a viable solution for decomposing synthetic dyes wastewater through utilizing the visible-light energy and cold-hot cycling.