LSPR-enhanced carbon-coated In2O3/W18O49 S-scheme heterojunction for efficient CO2 photoreduction

The special defect structure and localized surface plasmon resonance (LSPR) effect offer W18O49 extraordinary potential and research value in photocatalysis. The LSPR effect optimizes the design of W18O49-sensitized photocatalytic composites and broadens the light-response range of W18O49. However, the high-energy “hot electrons” generated by W18O49 under the LSPR effect exhibit an extremely short lifetime and cannot be fully utilized. Therefore, the high electron conductivity of carbon can be used to increase the rate of hot-electron transfer, thereby extending the lifetime of hot electrons. In this study, a heterojunction photocatalyst was formed by growing a high-absorbance one-dimensional nanowire W18O49 on the surface of carbon-coated porous In2O3 nanorods (C-In2O3) derived from In-MOF. The C-In2O3/W18O49composites exhibited optical responses in both the visible and near-infrared regions. The carbon coatings acted as transport channels to accelerate the transfer of carriers and hot electrons, and the activity of photocatalytic CO2 reduction (PCR) was significantly enhanced. The 40%C-In2O3/W18O49 composites had the highest CO yield in the photocatalytic reactions, which was 2.99 and 2.84 times greater than that of pure C-In2O3 and W18O49, respectively. The internal electronic transfer in the S-scheme heterojunction and LSPR-induced hot electrons injected into C-In2O3 achieved dual-path electron transfer for PCR.