Unraveling the activation insight of molecular oxygen in oxygen vacancy-enriched Cu/Cu 2 O Schottky junctions with dual LSPR effect toward high-efficient NIR light-driven photothermal catalysis

Abstract The development of efficient near-infrared (NIR) light-driven Cu2O-based photocatalysts and a deeper understanding of their underlying mechanisms for pollutant degradation are urgently needed. Herein, we report the rational design of oxygen vacancy-enriched Cu/Cu2O Schottky junctions via H2MoO4-template-assisted liquid-phase reduction method. Under NIR irradiation, the optimized Cu/Cu2O composite exhibits remarkable photothermal catalytic performance, achieving 85.1% degradation of tetracycline within 120 min. The enhanced activity is attributed to the synergistic effect of the Schottky junction, dual localized surface plasmon resonance (LSPR), and a unique “directional anchoring” mechanism for O2 activation. First, the Schottky junction formed at the Cu/Cu2O interface promotes efficient separation of photogenerated charges. Second, a dual LSPR effect, combining the intrinsic LSPR of Cu nanoparticles with the defect-state LSPR induced by oxygen vacancies, significantly enhances NIR light absorption and photothermal conversion efficiency. Most importantly, in-situ spectroscopic and density functional theory analyses reveal a unique “directional anchoring” mechanism for O2 activation at the oxygen vacancy (OV)-Cu interface. In this process, O2 is selectively captured at the OV–Cu dual sites, where electron transfer from the interface weakens the O–O bond, thereby facilitating the generation of reactive oxygen species. This work provides fundamental insights into the design of high-performance NIR-driven photothermal catalysts for environmental remediation.