Effect of water and annealing temperature of anodized TiO2 nanotubes on hydrogen production in photoelectrochemical cell

An efficient and economical technology for hydrogen production via solar water splitting in a newly designed photoelectrochemical (PEC) cell is reported. The core of the PEC cell is a membrane electrode assembly (MEA) that consisted of a TiO2 nanotube photoanode, a Pt/C cathode and alkaline membrane. The TiO2 nanotube arrays (NTs) were prepared by electrochemical anodization of titanium mesh in a mixed electrolyte solution of glycol and NH4F and then calcined at different temperature to transform the amorphous structure into crystalline. Effect of water content on the morphology of the TiO2NTs is investigated, and the optimal amount of water in the electrolyte is between 10 wt% and 80 wt%. Emphasis was the effect of the annealing temperature of anodized TiO2NTs on the hydrogen production in the PEC cell. The results indicate that the crystal phase and morphology of TiO2NTs are stable at 450 °C, which exhibits the best photocatalytic activity. Photocurrent generation of 1.55 mA/cm2 under UV-light irradiation under applied bias (0.6 V vs. Normal Hydrogen Electrode, NHE) shows good performance on hydrogen production.