Porous ZnO/Co 3 O 4 heteronanostructures are successfully fabricated by a novel one-step solid state conversion of a novel [(Zn) x −(Co) 7-x (BDC) (DHS)].nH 2 O (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 10 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/Co 3 O 4 nanostructure possesses relatively higher surface area (80-140 m 2 /g) and having significant N 2 gas sorption capacity in comparison with reported materials. It is suggested that synergistic effect of each component, higher separation of electron and holes, high 15 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. 20 65 achieved by choosing appropriate NCP precursors with special morphologies and under suitable experimental conditions. Calcinations of these materials produce a large amount of gas due to the decomposition of the organic ligands, and a porous structure is formed, which retains the shape of the precursor. 19-21 70 Binary, ternary or quaternary transition metal oxides are traditionally synthesized in laboratory using high-temperature

A novel silver deposited SnO2/NiO heteronanostructure is prepared and applied for the photocatalytic reduction of toxic aqueous Cr(vi) under visible light conditions.