Structural and electrochemical investigations of nanostructured NiTiO3 in acidic environment

Electrochemically stable nanostructured nickel titanate (NiTiO3) was prepared by sol-gel method and the structural and electrochemical properties were studied in the presence of H2SO4+CH3OH electrolyte. XRD and Raman studies confirmed the single phase of NiTiO3 with the rhombohedral structure. Thermal stability was studied by TGA. Microstructure analysis by SEM confirmed the uniformly distributed spherical shaped NiTiO3 particles, and TEM studies showed the spherical shaped particles with an average size of 90 nm. The UV-Vis analysis shows the absorption spectrum of NiTiO3, while the FTIR spectrum showed the vibrations related to Ni-O and Ti-O stretching. Electrochemical tests were carried out by cyclic voltammetry (CV) and polarization studies. The CV measurements were made at room temperature as well as at 60 degrees C: at room temperature, the NiTiO3 did not show any activity towards methanol oxidation whereas there observed an activity at the potential of 0.69 V at the operating temperature of 60 degrees C. The ilmenite structured NiTiO3 has oxygen vacancies, most probably on the surface, which could have also contributed to the methanol oxidation. Thus the nanostructured NiTiO3 is proposed to be an active support material for metal electrocatalysts.