ZIF-67-derived ultrathin Co-Ni layered double hydroxides wrapped on 3D g-C3N4 with enhanced visible-light photocatalytic performance for greenhouse gas CO2 reduction

CO2 photoreduction into high value-added chemicals shows great application prospects in the fields of environmental protection and renewable energy. However, the design and preparation of new heterogeneous photocatalysts with efficient CO2 photoreduction activity remains a challenge. Here, hierarchical cobalt-nickel layered double hydroxides (CNLDH) were confined on the surface of 3D g­C3N4 (NCN) to construct the CNLDH-NCN hybrids for photocatalytic reduction of CO2. The fabrication involves NaCl-template-assisted calcination, in-situ growth and in-situ etching. The CNLDH-NCN hybrids show a well-defined hierarchical and multi-hole structure, which promote the light-harvesting, charge separation and the adsorption of CO2. The optimal hybrids show high photocatalytic performance of CO2 to CO (27.67 μmol∙g-1∙h-1), which is 6.0-fold and 3.6-fold of NCN and CNLDH, respectively. The novel strategy successfully integrates hierarchical CNLDHs and NCN into a spatial conductive network frame with homogeneous and intimate interfacial contacts, boosting the photocatalytic performance. Meanwhile, it provides a new insight for the construction of a promising catalyst for solar energy conversion.