Hierarchical CsPbBr3 nanocrystal-decorated ZnO nanowire/macroporous graphene hybrids for enhancing charge separation and photocatalytic CO2 reduction

Abstract

Solar-driven CO₂ conversion for chemical fuel production has been regarded as an effective strategy to alleviate environmental and energy issues. In this study, we constructed a novel composite catalyst film, in which CsPbBr₃ nanocrystals (NCs) were loaded on a hierarchical branched ZnO nanowire (BZNW)/macroporous graphene scaffold (CsPbBr₃ NC/BZNW/MRGO). This well-designed multi-dimensional architecture rationally integrated the excellent visible-light absorption capability of CsPbBr₃ NCs, and fast charge transport and improved CO₂ capture ability afforded by ZnO nanowire-branched macroporous graphene. Due to this favorable synergistic effect, a boosted photocatalytic performance was achieved with a photoelectron consumption rate of 52.02 μmol g_cat⁻¹ h⁻¹ under visible light irradiation, which is 4.98 and 1.65 times higher than that of CsPbBr₃ NC (10.44 μmol g_cat⁻¹ h⁻¹) and CsPbBr₃ NC/MRGO (31.52 μmol g_cat⁻¹ h⁻¹), respectively. Furthermore, desirable CH₄ selectivity of up to 96.7% was achieved.