Effect of CoOOH loading on the photoelectrocatalytic performance of WO3 nanorod array film

A WO3-CoOOH composite film has been fabricated by photoelectrochemical deposition of CoOOH on the surface of WO3 nanorod arrays which are grown perpendicularly on the FTO substrate through solvothermal method. The films were characterized by field emission scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. For the films serving as the photoanodes, chopped linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) were measured in a three-electrode system. The photoelectrocatalytic activity was evaluated by the degradation of methylene blue (MB) under the simulated solar light illumination. CoOOH nanoparticles are evenly distributed on the surface of WO3 nanorod, which has a diameter of about 500 nm. The WO3-CoOOH composite film achieves the improved photoelectrocatalytic performance for the degradation of MB, which could be attributed to the effective hole transfer through the valency cycle of cobalt ion in the CoOOH.