TiO2 nanotubes modified with electrochemically reduced graphene oxide for photoelectrochemical water splitting

The photocatalytic water splitting into hydrogen and oxygen using solar light is a promising method to provide clean energy carriers in the future. Herein we report on an experimental investigation of TiO2 nanotubes (NTs) modified with electrochemically reduced graphene oxide (ERGO) for photoelectrochemical water splitting. A photocurrent density of 1.44 mA cm−2 at 1.23 V vs. RHE has been achieved for ERGO–TiO2 NTs photoanode under standard reporting conditions, i.e., simulated AM 1.5G sunlight (intensity 100 mW cm−2), which is notably increased by ∼140% compared to the bare TiO2 NTs. This efficiency is nearly ten times higher than that of the P25 nanoparticles based device. The enhanced photocurrent densities can be attributed to the reduced graphene oxide and Ti3 + self-doping produced by an electrochemical reduction treatment. The ERGO modified photoanodes show excellent stability during light soaking under full sunlight.