High-efficient Photoelectrochemical Reduction of Cr(VI) to Produce Chromium Formate over Pure Bi2S3 Thin Films

As a typical heavy metal ion pollutant in water and soil, Cr(VI) exhibits significant toxicity and carcinogenicity, which urges the development of an effective and environment-friendly technique for Cr(VI) treatment. Herein, bismuth sulfide (Bi2S3) photoanode is fabricated through a chemical bath deposition followed by sulfurization treatments. The structure and physicochemical characteristics of the thin films were analyzed and optimized. The obtained Bi2S3 thin films exhibit the photocurrent of 5.37 mA center dot cm(-2) at 1.22 V vs RHE. It can achieve 100% reduction efficiency of 70 ppm Cr(VI) solution in 1 h, and the reduction rate is 159.47 x 10(-3) mu mol center dot min(-1)center dot cm(-2). Further, the mechanism of the photoelectrochemical reaction was explored, and the reduced Cr(III) was converted into industrial raw material chromium formate, which realized the harmless recycling of Cr(VI)-contaminated wastewater.

Automated summary

In this study, a Bi2S3 photoanode was fabricated for the efficient treatment of Cr(VI) pollutants, achieving 100% reduction efficiency and enabling the recycling of Cr(III).