Fabrication and photoelectrochemical study of WO3-based bifunctional electrodes for environmental applications

Abstract

In this study, unique WO3-based bifunctional electrodes were prepared with the aim of achieving optimal photocatalytic and electrocatalytic activities of WO3 nanoplatelets and Pt nanoparticles, respectively. WO3 nanoplatelets with a high visible light response were directly grown on both sides of a tungsten substrate via a facile hydrothermal method. Pt nanoparticles were deposited on one side of the WO3 electrode, where they served as the electrocatalyst. The prepared electrodes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive X-ray spectroscopy (EDS) and cyclic voltammetry. Our experimental results revealed that the synthesized WO3 electrodes possessed high photochemical activity under visible light exposure, whereas the deposition of Pt nanoparticles with a large electrochemical active surface area significantly enhanced the electrocatalytic activity of the electrode. Various sets of photodegradation reactions involving Rhodamine B (RhB) were conducted to evaluate the efficacy of the WO3 electrodes, prior to and following the deposition of Pt nanoparticles under both visible light and applied potential. The bifunctional electrode exhibited far greater activity as compared to the WO3 electrode as the sole photocatalyst and WO3–Pt as the sole electrocatalyst, very promising for energy and environmental applications.