Enhancement of Persulfate Activation via Dual-Site Coordination and Electron Redistribution at Co─O─Zr Metal–Support Interfaces for Photo-Fenton-Like Reactions

Development of high-performance photocatalysts for persulfate activation is often limited by rapid electron–hole recombination and insufficient quantum efficiency. To overcome the challenges, electronic metal–support interaction (EMSI) structure is designed. The innovative structure has several key benefits: recombination rates are significantly reduced, charge separation is enhanced, and content of active sites and intrinsic catalytic activity are increased. ZrO 2 /Co 3 O 4 bimetallic oxides featuring a synergistic Co─O─Zr EMSI coordination are synthesized via a sol-gel method. Strong EMSI effects markedly modulate and stabilize the Co 3d electronic structure, creating an electron-rich center on Co sites to promote persulfate activation, and an electron-deficient center on Zr sites to adsorb atrazine. The Gibbs free energy analysis reveals that Zr incorporation reduces the overpotential of oxygen evolution reaction, thereby facilitating electron transfer, promoting hole consumption and suppressing charge recombination. More importantly, it promotes the generation of reactive oxygen species—predominantly via a singlet oxygen ( 1 O 2 )-dominated non-radical mechanism. The optimized catalyst achieves 97.3% degradation of atrazine (a model compound) under visible light, outperforming commercial catalysts (e.g., 4.5-fold of Co 3 O 4 ). The work elucidates the cooperative mechanism of dual-site engineering and EMSI-mediated electron redistribution, providing a rational strategy for designing efficient photocatalysts toward sustainable advanced oxidation processes.