Organic compounds, ammonia, and pathogenic microorganisms are major contaminants in sewage, posing health threats to humans and wildlife and need to be eliminated. Besides, H₂ is a green energy to break free our dependence on fossil fuels. Developing novel techniques to remove above-mentioned contaminants and produce green H₂ is of great importance. In this study, a multifunctional photoelectrochemical (PEC) system have been developed for coupled sewage treatment with H₂ evolution. BiVO₄-based photoanodes were developed for multifunctional PEC system, including BL-BiVO₄, MoS₂@BL-BiVO₄, and r-BiVO₄, presenting improved PEC performance through morphology engineering, heterojunction construction, and chemical reduction, respectively. BL-BiVO₄ can activate the added sulfite in a multifunct...[ Read more ]

Organic compounds, ammonia, and pathogenic microorganisms are major contaminants in sewage, posing health threats to humans and wildlife and need to be eliminated. Besides, H₂ is a green energy to break free our dependence on fossil fuels. Developing novel techniques to remove above-mentioned contaminants and produce green H₂ is of great importance. In this study, a multifunctional photoelectrochemical (PEC) system have been developed for coupled sewage treatment with H₂ evolution. BiVO₄-based photoanodes were developed for multifunctional PEC system, including BL-BiVO₄, MoS₂@BL-BiVO₄, and r-BiVO₄, presenting improved PEC performance through morphology engineering, heterojunction construction, and chemical reduction, respectively. BL-BiVO₄ can activate the added sulfite in a multifunctional PEC system to promote simultaneous pharmaceuticals and personal care products (PPCPs) degradation, H₂ evolution, and E. coli disinfection in synthetic and actual sewage under visible light irradiation. Mechanistic investigations showed that sulfite ions were activated by holes to produce sulfate radicals to boost contaminants removal and can scavenge holes to separate more electrons for increased H₂ generation. In addition, MoS₂@BL-BiVO₄ was used in the PEC system to treat actual sewage, simultaneously achieving complete PPCPs degradation and E. coli inactivation coupled with a large amount of H₂ generation. Furthermore, the r-BiVO₄ photoanode with a large surface area and high reactivity was synthesized using a chemical reduction process. The PEC/r-BiVO₄ process was able to treat saline sewage to meet local WWTPs’ discharge standards (for COD, ammonia, and E. coli) and significantly reduce operational carbon emissions due to the reduced generation of greenhouse gases and considerable H₂ production. It was revealed that the PEC system can activate chloride ions in sewage to generate numerous reactive chlorine species and facilitate ^•OH production, promoting contaminants removal. The PEC systems also exhibited excellent practicability, evidenced by their performance in various conditions and the good reusability and stability of the BiVO₄-based photoanodes.