Rational design of MoS2@COF hybrid composites promoting C-C coupling for photocatalytic CO2 reduction to ethane

Photocatalytic CO2 reduction into high-value C2+ products such as ethane is quite exciting but challenging due to multielectron steps involved and sluggish C-C coupling kinetics. Herein, a well-designed MoS2@COF hybrid composite is prepared for efficient and selective CO2 photoreduction to C2H6. In-depth experimental and theoretical studies reveal that the interfacial electric field built in the heterojunction accelerates the photogenerated electrons transfer from MoS2 to COF under light irradiation, greatly facilitating charge separation and transfer and thus enhancing the activity and C2H6 selectivity for CO2 photoreduction. The optimized MoS2@COF-15 achieves C2H6 production rate up to 56.2 μmol·g−1·h−1 with 83.8% of selectivity, which is about 8.6 and 31.2 times higher than that of pristine MoS2 and COF under identical conditions. The in-situ DRIFTS and DFT calculations indicate that the structure of MoS2@COF composite can promote the adsorption of *CO and the formation of *COCO, facilitating C-C coupling to convert into C2H6 product.