One dimensional ZnWO₄ nanorods coupled with WO₃ nanoplates heterojunction composite for efficient photocatalytic and photoelectrochemical activity

In this study, we report a novel semiconductor heterojunction of ZnWO₄/WO₃ composite successfully constructed through one-pot facile and eco-friendly in situ hydrothermal synthesis. The structural, morphological and photophysical property of ZnWO₄/WO₃ composite were investigated by powder X-ray diffraction (XRD), Raman spectrum, scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM), photoluminescence (PL) and transient photocurrent response. The morphological analysis indicated that ZnWO₄ nanorods are well distributed on the surface of WO₃ nanoplates. The ZnWO₄/WO₃ heterojunction composite possess strong light absorption in the visible region. To explore the photocatalytic activity of the prepared ZnWO₄/WO₃ heterojunction composite methylene blue (MB) was chosen as organic dye to assess the degradation ability of composite under visible light treatment. ZnWO₄/WO₃ heterojunction composite showed remarkable photocatalytic activity than that of pristine ZnWO₄ and WO₃. The elevated photocatalytic activity is attributed to the formation of heterojunction interface between WO₃ and ZnWO₄, leading to effective transfer and separation of photogenerated carriers in heterojunction. A plausible mechanism for the superior photocatalytic degradation over ZnWO₄/WO₃ heterojunction composites was also proposed.