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

Abstract

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 (R_electron) 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.