LSPR-assisted W18O49/ZnO S-scheme heterojunction for efficient photocatalytic CO2 N-formylation of aniline

Abstract

Designing highly efficient photocatalyst for the valorization of CO₂ is an ideal strategy to reduce greenhouse gas emissions and utilize solar energy. In this study, a S-scheme heterojunction photocatalyst is fabricated by solvothermal impregnation of ZnO on W₁₈O₄₉ for photocatalytic CO₂ N-formylation of aniline. The localized surface plasmon resonance effect of W₁₈O₄₉ improves the absorption capacity for long-wave light significantly, and the hot electrons generated in W₁₈O₄₉ with a high energy can migrate to the conduction band of ZnO and thus enhance the photocatalytic reduction ability. Meanwhile, the S-scheme heterojunction facilitates the separation of photoinduced charge carriers and preserves the redox ability of W₁₈O₄₉/ZnO composite photocatalyst. The conversion of aniline reaches 99.1% after 5 h reaction under visible light irradiation at room temperature with an N-formylaniline selectivity of 100%. A possible photocatalytic reaction mechanism is proposed. This study paves a promising way for the design of highly efficient photocatalyst and the sustainable utilization of CO₂.