TiO2 nanobelts with ultra-thin mixed C/SiO coating as high-performance photo/photoelectrochemical hydrogen evolution materials

Abstract Photoactive semiconductor materials that can convert light into chemical energy are desirable. Here, TiO2 nanobelts with ultra-thin mixed C/SiOx coating as a catalyst for water-decomposition were synthesized by a modified hydrothermal method and the in-situ graft-graphitization technique. The electrode prepared with as-prepared catalysts shows a significant photoelectrochemical activity for hydrogen evolution reaction (HER) in 2 M Na2SO3 solution. The current density reaches 44.69 mV∙cm2 at a potential of 0.9 V with a very high carrier density of 6.628 × 1030 cm−3. Under a combination of simulated solar irradiation and 500 mV bias, the electrode's hydrogen evolution efficiency reaches 6.36 mmol∙h−1∙cm−2. The results indicate that the synergistic effect of the ultra-thin carbon layer and SiOx promotes the separation and transfer of the charges on the nanobelts’ surface.