Promoted photocarriers separation in atomically thin BiOCl/Bi2WO6 heterostructure for solar-driven photocatalytic CO2 reduction

Exploring efficient strategies to promote photocarrier separation remains a challenge in solar energy conversion processes. Herein, we construct a novel atomically thin BiOCl/Bi2WO6 heterostructure to enhance photocarriers separation via the internal electric field at the heterointerface. The resultant atomically thin BiOCl/Bi2WO6 heterostructure exhibits superior photocatalytic CO2 reduction activity with a CH4 evolution rate of ca. 6.63 μmol g-1h−1 and 82.9% in selectivity under simulated sunlight irradiation without sacrificial reagent. The experimental characterizations highlight that the atomically thin heterostructure endows BiOCl/Bi2WO6 with an enhanced CO2 uptake capability and improved interfacial charge transfer behavior. Further theoretical calculations demonstrate that BiOCl/Bi2WO6 heterointerfaces are energetically more favorable for stabilizing the CHO*, which accounts for the improved photoreduction selectivity of CH4. This work is expected to provide inspiration for preparing other 2D atomically thin heterostructures employed in the solar energy conversion field.