▎ 摘　　要

Interfacial composite with improved carrier separation is promising to achieve multifunctionality and thus contribute to the carbon neutrality and sustainability of our society. Herein, we demonstrate a facile defect -assisted photo-reduction strategy to rationally design interfacial rGO/WO3_x composites with versatile proper-ties. Under light irradiation, the accumulated electrons in oxygen-defective WO3_x endow partial restoration of the pi network within GO nanosheets. The in-situ formed rGO/WO3_x not only broadens optical absorption but also accelerates carrier migration, enabling superior gas-sensing, photocatalytic and energy storage applications. When used as sensing material of smart sensors, the resultant rGO/WO3_x exhibits high response (8.4), low detection limit (92 ppb), good selectivity, fast response, and long-term stability (7 weeks) to ppm-level trie-thylamine. As an efficient photocatalyst, the photocatalytic kinetic of rGO/WO3_x towards visible-light-driven RhB degradation is promoted about 7 times as compared with that of pristine WO3_x. The synergism of suit-able components endows the rGO/WO3_x supercapacitor with high capacity (380F/g) over prolonged cycling. This work provided a successful approach for in-situ formation of interfacial composites and thus broadens the material's versatility for advanced nanotechnology.