BiVO4/TiO2 nanocomposite: Electrochemical sensor for hydrogen peroxide

Effect of interfering species on response currents of H 2 O 2 electrohemical sensor based on the BiVO 4 /TiO 2 nanocomposite electrode in saturated N 2 0.1 M NaOH solution at 0.5 V. • BiVO 4 /TiO 2 nanocomposites electrode is tested as an electrochemical sensor for sensitively detecting H 2 O 2 . • The synergic effect between TiO 2 and BiVO 4 improve the H 2 O 2 sensing performance of BiVO 4 /TiO 2 . • Long term stability and fast response of the BiVO 4 /TiO 2 composite electrode was investigated by CV . This study reports the synthesis of the BiVO 4 /TiO 2 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 BiVO 4 (monoclinic)/TiO 2 (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 H 2 O 2 . The BiVO 4 /TiO 2 nanocomposite 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 amperometry techniques. Due to the synergic effect and the nanometric character of the BiVO 4 /TiO 2 nanocomposite, the synthesized sensor shows an enhanced electrochemical sensing performance. Under optimal conditions, the H 2 O 2 sensing tests indicate that the as-prepared BiVO 4 /TiO 2 electrochemical sensor exhibits a low detection limit (5 μM), a high sensitivity (3014 μA/mM), which is two times larger than that of BiVO 4 and TiO 2 , a large linear range (5–400 μM), and long-term stability. Finally, the practical applications of the BiVO 4 /TiO 2 electrochemical sensor were also evaluated by analyzing H 2 O 2 in the presence of common interfering species such as uric acid, ascorbic acid, vitamin-B12, glycine, asparagine, glucose, urea, KNO 3 , NaNO 3 and NaCl. The as-obtained results confirm the high selectivity towards H 2 O 2 of the BiVO 4 /TiO 2 electrode. These results could open the route for potential applications of the BiVO 4 /TiO 2 -based sensor in many fields such as: biomedicine, environmental detection, electrochemical sensing and pharmaceutical analysis.