Coral-like WO3/BiVO4 photoanode constructed via morphology and facet engineering for antibiotic wastewater detoxification and hydrogen recovery

Morphology and facet engineering have been proved efficient strategies to prepare high-performance photoelectrochemical (PEC) materials. WO3/BiVO4 heterojunction photoanodes with different morphologies were prepared by simply controlling the amount of electrodeposited charge. The coral-like WO3/BiVO4 photoanode with the orientation growth of {110} and {011} active facets of BiVO4 exhibited the optimal PEC performance due to significantly enhanced separation and transfer of photogenerated charge carriers, while the exposure of {−121} facets showed negative effects. 4.71 mA·cm−2 and 2.9 mA·cm−2 of photocurrent densities were obtained for sulfite and water oxidation, respectively, superior to most reported results. Subsequently, a photoelectrochemical-chlorine (PEC-Cl) system was constructed for antibiotic wastewater detoxification with hydrogen recovery. The analysis results indicated that the system can quickly and effectively remove sulfamethoxazole and reduce its toxicity concurrent with high hydrogen yield. The reactive chlorine species (RCS), especially Cl2·− and ClO·, dominated the sulfamethoxazole removal. Possible degradation pathways of sulfamethoxazole were also elucidated.