1D S-scheme heterojunction of urchin-like SiC-W18O49 for enhancing photocatalytic CO2 reduction

Constructing heterojunction is an important method to improve the performance of photocatalyst for CO2 reduction. In this work, W18O49 nanosheets (NSs) were grown on the surface of SiC nanocages (NCs) to form the sea urchin ball morphology by solvothermal method. The SiC-W18O49 composite photocatalyst processes 1D S-scheme heterojunction electron transport pathway. The special urchin morphology provides a large surface area for the contact between photocatalyst and CO2 reactants. Meantime, the S-scheme internal electric field at the heterogeneous interface of SiC-W18O49 composite photocatalyst can effectively promote the separation and migration of photogenerated carrier pairs owing to 1D heterojunction structure. The photocatalytic CO2 reduction products (CO + CH4 + CH3OH) can be produced up to 21.87 μmol g−1 h−1 by SiC-W18O49 composite photocatalyst, which was 3.38 and 3.71 times of the total reduction activity of the parent SiC and W18O49, respectively. This work will provide a new idea for the design of heterojunction morphology and structure for boosting photocatalytic CO2 reduction.