WO₃–ZnO and CuO–ZnO nanocomposites as highly efficient photoanodes under visible light illumination

Abstract

We prepared ZnO nanocomposites with WO3 or CuO nanostructures to improve the photocatalytic performance of ZnO nanostructures. Characterization of the nanocomposites using scanning electron microscopy, x-ray diffraction, UV–vis spectrometry and photoluminescence revealed the morphologies and wide light absorption range of the materials. The highest current densities of WO3/ZnO and CuO/ZnO nanocomposites were 1.28 mA cm−2 and 2.49 mA cm−2 at 1.23 V (versus a reversible hydrogen electrode) under AM 1.5 100 mW cm−2, which are ~1.2- and 3.5-fold greater than those of bare ZnO nanostructures, respectively. The easy fabrication process suggests that nanocomposites with narrow bandgap materials, such as WO3 and CuO, will improve the performance of electrochemical and optoelectrical devices such as dye-sensitized solar cells and biosensors.

One-Step Dry Coating of Hybrid ZnO–WO3 Nanosheet Photoanodes for Photoelectrochemical Water Splitting with Composition-Dependent Performance

“…Photoelectrochemical (PEC) water splitting is a promising technique that involves the direct conversion of sunlight and water into electricity and hydrogen. This method is notably regarded as a simple, economical, and direct energy conversion route toward a sustainable, clean, and green society [1][2][3]. Presently, a major source of energy (80%) on earth comes from fossil fuels, such as oil, natural gas, and coal, which are rapidly depleting and unsustainable, resulting in a drastic change in climate through global warming and other forms of pollution.…”

“…Significant efforts have been made to advance metal oxide photoanodes (ZnO, TiO 2 , WO 3 , Fe 2 O 3 , and BiVO 4 ) [3,[6][7][8][9][10][11], particularly in heterostructured electrode forms, to improve system performance. Meeting the specifications of an efficient PEC water-splitting system using a single semiconductor presents challenges [12,13].…”