Electrochemical and microscopic characterization of titanium dioxide electrodes modified with platinum nanoparticles

This study investigates glass/Ti/Pt/TiO₂ surfaces, wherein Pt nanoparticles (NPs) were potentiostatically deposited with an amount of Pt that varies based on deposition time. The size and distribution of NPs were analyzed by scanning electron microscopy (SEM). Subsequently, a thicker titanium dioxide film was grown via anodization. Topography and roughness were examined by atomic force microscopy (AFM). Remarkably, TiO₂ grows independently of Pt NPs and remains stable under working conditions, including acid, neutral, and alkaline media. Under steady-state conditions, the open circuit potentials (OCPs) of the modified semiconductor/electrolyte interfaces corresponding to 1, 5, and 10 s of electrodeposited Pt, showed a shift of 167 mV, 42 mV, and 24 mV toward more positive values, respectively. Notably, these surfaces exhibit the activity of a Pt quasi-electrode and the band structure of a titanium dioxide semiconductor, making them ideal for use as photoanodes. In addition, it can be highlighted that the methodology employed in the preparation of the surfaces allows for reproducibility.