CdSIn bond bridging nanoflower shaped In2.77S4/Cd0.5Zn0.5S heterojunction modulation interface charge promotes photothermal catalytic CO2 reduction.

Photocatalytic CO2 reduction into solar fuels offers a promising strategy to alleviate energy shortages and environmental issues. Nevertheless, this process is severely restricted by rapid photocarrier recombination and insufficient CO2 activation capacity. Herein, a novel Z-scheme heterojunction In2.77S4/Cd0.5Zn0.5S with unique CdSIn interfacial bonds was rationally fabricated via the in-situ growth of Cd0.5Zn0.5S nanospheres on flower-like In2.77S4 nanoflowers. The formed CdSIn chemical bonds acted as high-speed electron transfer bridges, which steered photogenerated electrons towards ZnCd heteronuclear bimetallic sites through the Z-scheme charge transfer pathway and provided sufficient electrons for CO2 reduction. Meanwhile, the strong covalent coupling between two components reduced the surface charge density of Cd0.5Zn0.5S, effectively lowering the formation energy barriers of key C2 intermediates (*CO and *OCCO) and greatly promoting CO2 adsorption and activation. Benefiting from the above advantages, the flower-like In2.77S4/Cd0.5Zn0.5S heterojunction delivered remarkable photothermal CO2 photoreduction performance. For the optimal sample, the evolution rates of CO and C2H4 reached 100.95 μmol·g-1·h-1 and 18.43 μmol·g-1·h-1, respectively. These values were 14.87 and 8.53 times higher than those of Cd0.5Zn0.5S, as well as far superior to In2.77S4. This work provided a feasible and innovative route for the construction of high-efficiency photocatalysts towards selective CO2 conversion into high-value C2 products.