Boosting photo-Fenton degradation via high-selectivity singlet oxygen-induced S-scheme heterojunction

Novel Yb-BiOI/Ce-MgAl-LDH S-scheme heterojunction boosts photo-Fenton degradation. • Substrate molecular orbitals govern the selective 1 O 2 -dominated degradation. • S-scheme heterojunction achieves 100% TC-HCl degradation within 20 min. • The system demonstrates excellent environmental adaptability and stability. • Photocatalytic mechanism elucidated via experiments and DFT calculations. Developing highly selective catalytic systems remains a grand challenge in advanced water remediation. A novel S-scheme Yb-BiOI/Ce-MgAl-LDH heterojunction was rationally designed to synergistically boost photo-Fenton degradation via targeted singlet oxygen ( 1 O 2 ) generation. Unambiguously validated by in situ XPS and density functional theory (DFT) calculations, the S-scheme charge-transfer pathway efficiently accelerated spatial carrier separation while preserving maximum redox potentials. Consequently, the composite rapidly degraded the parent tetracycline hydrochloride within 20 min and achieved a mineralization efficiency of 52.5%, exhibiting outstanding degradation performance. Crucially, mechanism studies and density functional theory analyses have demonstrated that this highly selective reaction process, driven primarily by 1 O 2 as the dominant reactive oxygen species, is essentially determined by the energy levels of the specific molecular orbitals of the substrate. Pathway elucidation, coupled with in silico predictions and empirical phytotoxicity bioassays, comprehensively confirmed the substantial reduction in intermediate ecotoxicity. Ultimately, the scientific value of this work lies in providing deep mechanistic insights into S-scheme-driven selective oxidation, offering a robust and sustainable paradigm for designing targeted detoxification systems in wastewater treatment. Download: Download high-res image (262KB) Download: Download full-size image