Visible Light Active WO₃/TiO₂ Heterojunction Nanomaterials for Electrochemical Sensor, Capacitance and Photocatalytic Applications

Developing the high-efficiency photocatalyst of low-cost synthesis is a more important implication in the field of research. Thus versatile applicable nanomaterial need of search leads us to synthesize WO3:TiO2 (1:2 to 1:8) photocatalysts through the ultra-sonication-assisted co-precipitation method for sensing heavy metal ion (lead) and the degradation of reactive blue 4 dye under visible light irradiation. The synthesized material has been confirmed by the characterization techniques such as powder X-ray diffraction (PXRD) & Rietveld Refinement for the crystal size ranges from 8 to 13 nm. Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS) for surface morphology and elemental confirmation. The band gap evaluated from Ultra-violet Visible-Diffuse reflectance spectroscopy (UV-DRS) is 3.1-3.4 eV. Having aggregable size, the photocatalyst WO3:TiO2 (1:6) showed better results when compared to other ratios. Electrochemical sensor action for lead ion detection was conducted by graphite assisted with WO3:TiO2 (1:6) electrode paste in 0.1 M KCl electrolyte. Photocatalytic degradation of reactive blue 4 dye was conducted under visible light and achieved 84% degradation. It shows that the better capacitance value of 24.7 x 10(-2) F/g for WO3 proves to be a better capacitor application.