Constructing plasmonic semiconductor S-scheme heterojunction for deep toluene oxidation

Plasmonic/semiconductor heterojunctions have shown remarkable potential for advancing photochemical reactions, yet the reliance on noble metals in conventional plasmonic systems imposes prohibitive costs for solar-driven applications. Herein, we report the plasmonic semiconductor (WO 3 -OV) with full spectral response by pre-irradiation for the first time. The near-infrared light effectively excites the surface plasmon resonance (SPR) of WO 3 -OV, generating high-energy hot electrons capable of multi-electron transfer processes. Coupling WO 3 -OV with a band-matched semiconductor (TiO 2 ) establishes an internal electric field (IEF) at the heterointerface, which synergistically enhances charge separation and prolongs carrier lifetimes. Crucially, oxygen vacancies (OVs) in WO₃-OV serve dual roles: (1) as plasmonic centers for NIR photon harvesting and (2) as catalytic active sites for toluene oxidation. The synergistic effect of heterojunction and plasmonic was elucidated through comprehensive in situ characterization and theoretical calculation. The rational integration of LSPR, defect engineering, and interfacial charge control provides a universal framework for designing high-efficiency photocatalytic systems for environmental remediation and energy conversion.