High-efficient Photoelectrochemical Reduction of Cr(VI) to Produce Chromium Formate over Pure Bi 2 S 3 Thin Films

• Published in: Journal of the Electrochemical Society Vol. 169; no. 11; p. 116503
• Main Authors: Hou, Yueru, Wang, Hongbin, Wang, Jun, Liu, Fangyaang, Zhang, Zongliang, Jia, Ming, Jiang, Liangxing
• Format: Journal Article
• Language: English
• Published: 01.11.2022
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1945-7111/ac9e23

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 (Bi 2 S 3 ) 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 Bi 2 S 3 thin films exhibit the photocurrent of 5.37 mA·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 × 10 −3 μ mol·min −1 ·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. Highlights Bi 2 S 3 exhibits the photocurrent of 5.37 mA·cm −2 at 1.22 V vs. RHE. Bi 2 S 3 can achieve 100% reduction efficiency of 70 ppm Cr(VI) solution in 1 hour. The reduced rate of Cr(VI) by Bi 2 S 3 is 159.47 × 10 −3 μ mol·min −1 ·cm −2 . We explored the mechanism of photoelectrochemical reduction of Cr(VI). Chromium formate is prepared by changing the pH of the reduced solution.