Improved photoelectrocatalytic properties of ZnO/CuWO4 heterojunction film for RhB degradation

In this work, we report on the photoelectrocatalytic properties of nanostructured ZnO/CuWO4 heterojunction film prepared by combining the hydrothermal and doctor-blade methods. For ZnO and CuWO4 heterojunction films, X-ray diffraction (XRD) spectra showed the wurtzite and triclinic structure phases, respectively, and no deleterious phases were observed. Scanning electron microscopy (SEM) images showed ZnO nanorods (NRs) grown perpendicular to the substrate and a CuWO4 nanoparticle surface coating on the ZnO/CuWO4 film. The formation of heterojunction film allowed a greater use of visible light and better photoelectrochemical behavior for the ZnO/CuWO4 film. The ZnO, CuWO4, and ZnO/CuWO4 films were used for electrochemically assisted (PEC) RhB photodegradation. The ZnO/CuWO4 film had a PEC photodegradation efficiency of 82 %, making it approximately twice as effective as ZnO film. The incorporation of CuWO4 into the ZnO NR array film with a bias potential remarkably promoted the photogenerated carrier separation and increased the use of photogenerated carriers in photocatalytic reactions, resulting in a higher photocatalytic activity under visible light.