Integrated S-Scheme Heterojunction of Amine-Functionalized 1D CdSe Nanorods Anchoring on Ultrathin 2D SnNb2O6 Nanosheets for Robust Solar-Driven CO2 Conversion

Photocatalytic CO2 reduction to value-added fuels is an appealing avenue in response to global warming and the energy crisis, but it still suffers from high energy barriers, low conversion efficiencies, and poor photostability. Herein, a novel S-scheme SnNb2O6/CdSe-diethylenetriamine (SNO/CdSe-DET) heterojunction is designed by a microwave-assisted solvothermal process, composed of 2D ultrathin SNO nanosheets (NSs) and amine-modified CdSe-DET nanorods (NRs). The SNO/CdSe-DET composite without any co-catalyst possesses a boosted performance in the solar-driven photocatalytic conversion of CO2 to CO, and the highest CO evolution rate achieved is 36.16 mu mol g(-1) h(-1), which is roughly 3.58 and 9.39 times greater than those of CdSe-DET and SNO under visible-light illumination. Such a superior activity should be ascribed to the S-scheme system, which benefits the separation of the photogenerated carriers and promotes the synergy between CdSe-DET NRs and SNO NSs by strong chemical-bonding coordination. Meanwhile, DET can enhance CO2 adsorption/activation and precisely regulate the surface reactive sites. This innovative work provides fresh insight into the development of highly efficient S-scheme photocatalytic heterostructures for CO2 reduction.

Automated summary

A novel S-scheme SnNb2O6/CdSe-diethylenetriamine heterojunction was designed and showed enhanced activity in the solar-driven photocatalytic conversion of CO2 to CO, attributed to the synergy between CdSe-diethylenetriamine nanorods and SNO nanosheets in the S-scheme system.