Self-adaptive synchronous modulation of multi-junctions within immobilized CuOx mesh for durable photocatalysis-coupled sulfite-based AOPs

An immobilized copper composite oxide mesh catalyst (CuO x ) featuring self-adaptive multi-junction interfaces was developed to address the inherent pH and oxygen sensitivities that typically restrict the efficiency of sulfite-based advanced oxidation processes (S(IV)-AOPs), thereby enabling visible light-assisted efficient degradation of sulfisoxazole under neutral S(IV)-containing conditions. Impressively, the CuO x -S(IV)/Vis system achieved 86.5% removal within 90 min and exhibited remarkable long-term stability over consecutive reaction cycles, attributed to the synchronous modulation within its dual-mechanism framework. Integrated experimental characterizations and First-principles computations demonstrated that the mutual reinforcement between S(IV) autoxidation and Vis-driven photocatalysis originates from the dynamic evolution of the internal multi-junction architecture, comprising internal electric field (IEF) across p-p and p-n heterojunctions as well as Schottky junctions that facilitate internal electron extraction (IEE). This work offers fundamental insights into regulating Vis-induced oxy-sulfur radical pathways via complementary and synergistic mechanisms, providing a viable strategy toward sustainable and efficient catalytic water purification. • Immobilized CuO x mesh was developed for sulfisoxazole removal under neutral S(IV)/Vis conditions • Dynamic evolution during the coupled reactions mediated via copper composite oxides was confirmed • Immobilized CuO x -S(IV)/Vis maintained superior performance in multiple consecutive sequences • Self-adaptive synchronous modulation of multi-junctions within CuO x was identified and computed • Vis-induced oxy-sulfur radical pathway regulations via complementary mechanisms were proposed