In Situ Electrochemical Synthesis of Squamous-like Cu₂S Induced by Sulfate-Reducing Bacteria as a Fenton-like Catalyst in Wastewater Treatment: Catalytic Performance and Mechanism.

Abstract

In this paper, a novel method was proposed for the synthesis of Cu₂S on copper mesh via electrolysis in SRB culture medium. It was found that following electrolysis in SRB medium, squamous-like Cu₂S arrays were obtained on the copper mesh, and the Cu₂S loading contents varied with the electrolyzing parameters. The resultant Cu₂S on copper mesh in SRB (CSCM-SRB) with the highest catalytic MB degradation properties was produced by electrolysis at 3.75 mA/cm² for 900 s. The optimized MB-degrading conditions were determined to be 1.2 cm²/mL CSCM-SRB with 0.05 M H₂O₂ at 35 °C when pH = 6, under which the degradation of MB reached over 99% after 120 min of reaction. Disinfecting properties was also proven by antibacterial tests, revealing that an almost 100% antibacterial rate against <i>E. coli</i> was obtained after 8 min. The organic compounds produced by SRB adsorbed on CSCM-SRB strongly promoted the degradation of MB. Furthermore, possible Fenton-like mechanisms of CSCM-SRB were proposed, illustrating that ·O₂^-, ·OH, and ¹O₂ acted as the main functional species during Fenton-like reactions, leading to effective MB degradation and high antibacterial properties. Finally, a simple device for wastewater treatment was designed, providing possible applications in real environments.