Porous ZnO/Co3O4 heteronanostructures derived from nano coordination polymers for enhanced gas sorption and visible light photocatalytic applications

Abstract

Porous ZnO/Co₃O₄ heteronanostructures are successfully fabricated by a one-step solid state conversion of a novel [(Zn)_x–(Co)_7−x(BDC)(DHS)]·nH₂O (x = 1, 3, 4, 6)] nano coordination polymers (NCPs). The precursor is prepared by one-pot wet chemical approach at room temperature without any surfactant using dihydroxy salophen ligand and 1,4-benzenedicarboxylic acid as the linkers in presence of zinc(II) acetate and cobalt(II) acetate in DMF solvent. Different weight ratios of the Zn/Co are fabricated in situ into the hetero-structures during the preparation of the NCPs to tune their physicochemical properties. The produced ZnO/Co₃O₄ nanostructure possesses relatively higher surface area (80–140 m² g⁻¹) and having significant N₂ gas sorption capacity in comparison with reported materials. It is suggested that synergistic effect of each component, higher separation of electron and holes, high surface area and porous structure led to the promising visible light photocatalytic properties. The prepared mixed metal oxides show significant reusability in photocatalysis more than five times without losing their properties. Importantly, the mixed-metal NCPs could be applied as an effective route to generate not only binary oxide, but also ternary or quaternary oxide nanostructures with desired morphology and enhanced physicochemical properties.