Ce/Cu-MOF-Derived AgAu–C/N–CeO ₂ @C/N–CuO S-Scheme Nanohybrids for Photocatalytic H ₂ O ₂ Production and Photo-Fenton Antibiotic Degradation

Escalation of global energy scarcity and water pollution by pharmaceutical waste is compounding the crisis by accelerating the spread of multidrug-resistant genes, imposing a serious threat to environmental, health, and economic burdens. Photocatalytic H₂O₂ production via O₂ reduction reaction (ORR) along with pharmaceutical pollutant (Ofloxacin (OFL)) degradation offers a promising avenue to achieve the goal of energy and environmental sustainability. However, enhancing the stability and activity of a photocatalyst remains a challenge due to the sluggish reaction kinetics and recombination of charge carriers. Herein, we designed AgAu-loaded bimetallic MOF (Ce/Cu-MOF)-derived C/N-CeO₂@C/N-CuO (C/N-CCO@AgAu) heterostructure through hydrothermal, calcination, and photoreduction methods that significantly improves the activity of the nanocomposite. As anticipated, the C/N-CCO@AgAu catalyst exhibits an exceptional H₂O₂ production rate of 3289.3 μmol g^-1 h^-1 and a solar to chemical conversion efficiency of 0.13%, surpassing neat CeO₂, C/N-CeO₂, and composite C/N-CCO by 2.7-, 2.2-, and 1.3-fold, respectively. Additionally, the catalyst depicts enhanced in situ photo-Fenton OFL degradation (91% in 1 h). It is revealed that effectively anchoring plasmonic metal nanoparticles over C/N-CCO surface with surface oxygen vacancies (Ovs) not only improves the photocatalytic performance via localized surface plasmon resonance (LSPR) photothermal effect but also extends the life span of exciton pairs through trapping electrons. The S-scheme charge transfer dynamics pathway in C/N-CCO@AgAu is verified through a reactive intermediate trapping test and ESR analysis. This work provides insights into the plasmon-induced photothermal-photocatalytic energy generation process.