Ultrathin In2O3-Ov/ZnAl-LDH-Ov S-scheme heterojunctions with oxygen-rich vacancies for efficient photocatalytic peroxymonosulfate activation for the degradation of nitenpyram

In advanced oxidation processes (AOPs) based on peroxynitrite (PMS), generating reactive radicals efficiently and consistently is challenging due to high electron occupancy and slow conversion rates of PMS. In this study, ultrathin In2O3 with oxygen vacancies (Ov) was combined with ultrathin ZnAl-LDH to construct S-scheme In2O3Ov/ZnAl-LDH-Ov heterojunctions. The presence of Ov promotes the formation of charge-transfer channels (Al-OIn bonding) at the interface of these heterojunctions, thereby reducing electron occupancy and enhancing the generation of active radicals in the InLDH/PMS/Vis system. This S-scheme heterojunction facilitates the acceleration of photogenerated electrons, leading to the rapid conversion of PMS into hydroxyl (center dot OH) and sulfate radicals (SO4- center dot), and promotes swift electron transfer. Consequently, the InLDH/PMS/Vis system demonstrates exceptional degradation efficiency for a wide range of organic pollutants and a high removal capacity in treating real industrial wastewater. This investigation offers a novel perspective on the coordination mechanisms between photocatalysis and PMS activation.