Pollutant-specific reactive species fingerprints: elucidating differential photocatalytic antibiotic degradation mechanisms in ZnIn2S4-based systems.

Antibiotics-containing wastewater have received much attention worldwide because of its potential harm to humans and aquatic life. Traditional advanced oxidation processes (AOPs) could activate dioxygen or oxidizing agents into diverse reactive oxygen species (ROSs) for the purification of antibiotics-containing wastewater, the indiscriminate attack of ROSs to substrates usually leads to the incomplete decomposition of targeted pollutants or generation of more toxic byproducts. In contrast, the eco-friendly semiconductor photocatalysis can directly utilize free sunlight to generate reactive photogenerated electrons and holes, or activate oxygen/water into ROSs, exhibiting enormous potential to degrade antibiotics pollutants. Among the advanced photocatalysts, the low-toxicity Zinc indium sulfide (ZnIn2S4) photocatalyst with the tunable band gap, short migration distance of photocarriers and abundant active sites, was widely used in photocatalytic H2 evolution and organic contaminants removal. This paper summarizes the advancement of ZnIn2S4-based photocatalysts in the degradation of antibiotics-containing wastewater, focusing on the degradation efficiency of antibiotics in different systems and contribution of different active species to target pollutants molecules. We analyzed the mechanism of reactive species (RS) generation and RS-involved antibiotic degradation paths, dissected the possible attack sites of antibiotics, as well as summarized the generated intermediates during the photodegradation process. Finally, we proposed the challenges and prospects of ZnIn2S4-based photocatalysts to purify the antibiotics-containing wastewater. This review might contribute to designing advanced ZnIn2S4-based photocatalysts and constructing efficient photocatalytic reaction system for the treatment of antibiotics-containing wastewater.