Effect of different nano-structured Ag doped TiO2-NTs fabricated by electrodeposition on the electrocatalytic hydrogen production

Abstract In this study, TiO 2 -NTs electrode was successfully fabricated by two-step anodization technique. Then, different Nano-structured Ag was loaded on the surface of as prepared TiO 2 -NTs using electrodeposition method at various deposition times. The morphology, composition and structure of Ag doped TiO 2 -NTs were determined by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results showed that nanoparticle and nanodentrict Ag were formed on the TiO 2 -NTs depending on the deposition time and the particle size of anatase TiO 2 increased with increasing Ag doping concentration. To evaluate the electrocatalytic properties of Ag doped TiO 2 -NTs towards the hydrogen evolution reaction (HER), the cyclic voltammetry, cathodic polarization curves and impedance measurements were recorded in 1 M KOH. The electrochemical data indicated that nanodentrict Ag doped TiO 2 , having the highest charge carrier density (9.02.10 29  cm −3 ) as revealed by Mott–Schottky analysis, exhibits the most effective electrocatalytic activity towards the HER. In addition, long term stability of TiO 2 -NTs and Ag–TiO 2 -NTs electrodes and the energy requirement for the electrolytic hydrogen evolution were examined.