Three-dimensional MoS2/graphene aerogel-driven visible-light photocatalysis assisted by persulfate or hydrogen peroxide for rapid degradation of tetracycline

Abstract

The integration of various advanced oxidation processes (AOPs) can provide an optimal balance between treatment efficiency and duration, ensuring that wastewater is adequately treated while minimizing costs and maximizing operational performance. In this study, heterogeneous photocatalysis using a molybdenum disulfide/graphene aerogel (MGA) composite was integrated with hydrogen peroxide (H₂O₂) or persulfate (PS)-assisted AOPs to remove tetracycline (TC), a commonly detected antibiotic contaminant in aquatic environments. Specifically, the study assessed the effects of operating parameters, such as PS/H₂O₂ concentration, pH, initial pollutant concentration, catalyst dose, and the presence of inorganic anions on TC removal in a systematic manner. It was found that the MGA/PS system exhibited significantly greater degradation activity compared to MGA/H₂O₂, pure MGA, PS, and H₂O₂ alone. Notably, the MGA/PS system achieved complete removal of TC within 60 min of visible-light irradiation under optimized conditions. Furthermore, an average TC removal rate of approximately 85.5 % was observed in real wastewater during the same reaction period. This enhancement was attributed to PS facilitating the generation of free radicals and acting as an electron acceptor, which reduced the recombination of photoinduced charge carriers, thereby improving electron–hole separation efficiency. The outcomes of this study provide valuable insights for developing highly effective techniques for treating antibiotic-laden wastewater through the integration of MGA with PS-based AOPs.