Nanoribbon-structured CdWO4–ZnO for multiple applications

Abstract

A new cadmium tungstate–zinc oxide (CdWO4–ZnO) nanocomposite, prepared by a simple hydrothermal method, was characterised by X-ray powder diffraction, high-resolution transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy, elemental colour mapping, atomic force microscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy and Brunauer–Emmett–Teller (BET) surface area measurements. FE-SEM and TEM images show the heterostructure of cadmium tungstate–zinc oxide with nanoribbons and nanoparticles. The BET surface area of cadmium tungstate–zinc oxide is 2·1 times that of zinc oxide. This heterostructured material shows an enhanced photocatalytic activity on the degradation of rhodamine B and reactive orange 4 under ultraviolet A light irradiation. Cadmium tungstate–zinc oxide exhibits higher electrocatalytic activity than zinc oxide and cadmium tungstate for methanol electrooxidation in alkaline medium. This coupled oxide shows increased hydrophobicity, compared to cadmium tungstate or zinc oxide. A significant antibacterial activity against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli was shown by this catalyst. The results offer new insights into the performance of a coupled semiconductor oxide with multiple applications in photocatalytic, electrocatalytic, self-cleaning and antibacterial activities.