A Co3O4-embedded porous ZnO rhombic dodecahedron prepared using zeolitic imidazolate frameworks as precursors for CO2 photoreduction

Abstract

Metal–organic frameworks (MOFs) are attracting considerable attention for their use as both the precursor and the template to prepare metal oxides or carbon-based materials. For the first time in this paper, the core–shell ZIF-8@ZIF-67 crystals are thermally converted into porous ZnO@Co₃O₄ composites by combining a seed-mediated growth process with a two-step calcination. The designed porous ZnO@Co₃O₄ composites exhibited the highest photocatalytic activity with an excellent stability for the reduction of CO₂ among the commonly reported composite photocatalysts. Their superior photocatalytic performance is demonstrated to be resulting from the unique porous structure of ZnO@Co₃O₄ and the co-catalytic function of Co₃O₄ which can effectively suppress the photocorrosion of ZnO.