Highly enhanced photocatalytic Cr(vi) reduction using In-doped Zn(O,S) nanoparticles

Efficient photocatalytic reduction of highly toxic hexavalent chromium pollutants obtained from wastewater has become the focus of research these days due to their ecological and environmental influence. Here, indium doped zinc oxysulfide nanoparticles with different indium precursor contents were prepared using a facile low-temperature method to reduce highly toxic Cr(vi). The as-prepared photocatalysts were characterized by using different techniques. The photocatalytic activities of the as-prepared nanoparticles were evaluated by the photocatalytic reduction of Cr(vi). ZnInOS-5 with 5 molar percentage indium precursor exhibited a 99.9% reduction of Cr(vi) within 3 minutes of light irradiation. The rate of Cr(vi) reduction by ZnInOS-5 was 46 times faster than that of In-free ZnInOS-0. The enhanced photocatalytic activities of In-doped Zn(O,S) were attributed to its small particle size, low charge-transfer resistance, and low recombination rate of photo-generated holes and electrons. Due to its excellent performance, ZnInOS-5 is an ideal candidate for photocatalytic Cr(vi) detoxification.