A new 0D–2D CsPbBr3–Co3O4 heterostructure photocatalyst with efficient charge separation for photocatalytic CO2 reduction

The effective spatial separation of photogenerated charge carriers is essential for realizing efficient CO2 conversion. Herein, a new CsPbBr3–Co3O4 heterostructure photocatalyst was rationally developed for photocatalytic CO2 reduction. A facile synthetic strategy based on electrostatic interactions was utilized. The results revealed that the CsPbBr3–Co3O4 hybrid exhibited a boosted evolution rate of 64.6 μmol g−1 h−1 (CO: 35.40 μmol g−1 h−1; CH4: 29.2 μmol g−1 h−1) with an electron consumption rate (Relectron) of 304.4 μmol g−1 h−1, surpassing pristine CsPbBr3 or Co3O4. The high activity mainly arises from efficient charge separation and the directional transfer of electrons from CsPbBr3 to Co3O4via an intimately coupled heterointerface. Notably, the surface features (derived from the unique morphology) expedited the CO2 adsorption and accumulation of electrons at the Co3O4 site which ultimately facilitated the conversion of CO2 over the CsPbBr3–Co3O4 composite. This approach provides a strategy to design and modulate highly active metal oxide and perovskite-based photocatalysts and presents great potential for constructing a heterointerface for CO2 reduction.