Cyclic voltammetry deposition of nickel nanoparticles on TiO2 nanotubes and their enhanced properties for electro-oxidation of methanol

- Cyclic voltammetry deposition for depositing nickel nanoparticles on TiO2 nanotubes.
- Dependency of dispersion, size, and morphology of Ni nanoparticles on pH and scan rate.
- Improved electro-activity properties of Ni/TiO2 nanotubes.

We report on the fabrication of nickel/TiO2 nanotube composites on titanium substrate by cyclic voltammetry deposition and direct current (DC). TiO2 nanotubes were produced by anodic oxidation in an organic electrolyte. DC electrodeposition provides agglomerated nickel particles mainly accommodated on top surface of TiO2 nanotubes. The cyclic voltammetry deposition is shown to provide well dispersed nanoparticles characterized by microscopical and X-ray diffraction methods. We mention that by tuning electrolyte pH and potential scan rate highly dispersed Ni nanoparticles will be achieved. The electro-activity properties of Ni/TiO2 nanotubes electrodeposited under different cyclic voltammetry deposition conditions in an alkaline media consisting of methanol are studied to verify the quality of surface modification of TiO2 nanotube with nickel nanostructures. According to scanning electron microscopy examinations, we find that at a pH = 5 and a scan rate 20 mV·s− 1, the smallest Ni nanoparticles with the best dispersion on TiO2 nanotubes is achieved which indeed, exhibit the best electro-activity property. It is here confirmed that Ni nanoparticles produced by cyclic voltammetry deposition on TiO2 nanotubes can be used as an efficient sensitive electrode in electrochemical methanol devices.

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