One-Step Electrodeposition of Nanocrystalline TiO2 Films with Enhanced Photoelectrochemical Performance and Charge Storage

With the rapid development of renewable energy technologies there is an urgent need to find synthesis routes that address the needs of materials in a reproducible and affordable way. In this study, we present a one-step electrochemical method for the deposition of nanocrystalline titanium dioxide films on different carbon substrates. By optimizing the synthetic conditions, electrodeposition of nanocrystalline and porous titanium dioxide layers was achieved in only a few minutes. To deconvolute the complex effect of the solution pH and temperature, as well as the deposition potential, a set of systematic experiments was carried out on glassy carbon electrodes. The robustness and general applicability of this synthetic approach is demonstrated by extending it to graphene film electrodes. The phase composition of TiO2 was controlled by varying the solution composition. The photoelectrochemical performance of the electrodeposited titanium dioxide films was better than, or at least comparable to the benchmark P25 titanium dioxide films. Hydrogen-ion intercalation measurements for the TiO2/graphene electrodes indicated promising charge storage capacity, which might be exploited in the future in Li-ion batteries.