Facile photocatalytic reduction of carcinogenic Cr(<scp>vi</scp>) on Fe-doped copper sulfide nanostructures

Abstract

In this study, Fe-doped copper sulfide nanoparticles (NPs) were investigated for the solar-assisted reduction of Cr^VI ions in raw water. The Fe-doped NPs were synthesized by decomposing copper(ii) <i>N</i>,<i>N</i>-diphenylmethylpiperazinecarbamodithioate <i>via</i> a facile single-step, one-pot solvothermal method in the presence of iron salt. The Cr^VI photoreduction data were fit to a pseudo-first-order kinetic model and a Langmuir model. The CuS/Cu₂S NP reduction ability for Cr^VI increases with an increase in dopant percentage. The best catalyst (9% Fe-doped) was able to reduce Cr^VI (10^-4 M K₂Cr₂O₇) to Cr^III in raw water using an initial amount of 10 mg in 6 min with a reduction efficiency of up to 100%. The photocatalytic activity was examined while varying five different parameters: sunlight, diffused light, change in pH, and changes in the concentration of the catalyst and the temperature. This new approach presents an active, simple, and cost-effective means for wastewater treatment.