BiVO4/TiO2 nanocomposite: Electrochemical sensor for hydrogen peroxide

Abstract This study reports the synthesis of the BiVO4/TiO2 nanocomposite in optimized conditions using the hydrothermal route. By varying many experimental parameters such as the temperature, the hydrothermal reaction time, the pH of the solution and the surfactant’s nature, we have successfully obtained BiVO4 (monoclinic)/TiO2 (anatase) nanomaterials with different morphologies. These materials were characterized by X-ray powder Diffraction (XRD), Infrared Spectroscopy (IR) and Scanning Electron Microscopy (SEM). The as-prepared nanocomposites were employed to manufacture hybrid electrode sensors to detect H2O2. The BiVO4/TiO2nanocomposite was deposited on nickel foam which acts as the working electrode. The response to hydrogen peroxide on the formed electrode was examined using cyclic voltammetry and amperometrytechniques. Due to the synergic effect and the nanometric character of the BiVO4/TiO2 nanocomposite, the synthesized sensor shows an enhanced electrochemical sensing performance. Under optimal conditions, the H2O2 sensing tests indicate that the as-prepared BiVO4/TiO2 electrochemical sensor exhibits a low detection limit (5 µM), a high sensitivity (3014 µA/mM), which is two times larger than that of BiVO4 and TiO2, a large linear range (5 to 400 µM), and long-term stability. Finally, the practical applications of the BiVO4/TiO2 electrochemical sensor were also evaluated by analyzing H2O2 in the presence of common interfering species such as uric acid, ascorbic acid, vitamin-B12, glycine, asparagine, glucose, urea, KNO3, NaNO3 and NaCl. The as-obtained results confirm the high selectivity towards H2O2 of the BiVO4/TiO2 electrode. These results could open the route for potential applications of the BiVO4/TiO2-based sensor in many fields such as: biomedicine, environmental detection, electrochemical sensing and pharmaceutical analysis.