Dimensional control of titanium dioxide nanotube arrays with hydrogen peroxide content for high photoelectrochemical water splitting performance

Adding hydrogen peroxide (H2O2) for the fast formation of titanium dioxide (TiO2) nanotube arrays produce smooth and clean TiO2 nanotubes without bundling and cracking problems. The nanotube formation rate accelerated after the periodical addition of H2O2 at different intervals. Adding H2O2 at 10 min intervals formed longer nanotubes (13 µm) with larger pore diameters (140 nm). These novel TiO2 nanotubes exhibited optimal photocurrent density (1.8 mA/cm2) and 3.8% photoconversion efficiency because of high crystallinity with numerous oxygen vacancies in the large pore diameters allowed for better light absorption and good interaction between the electrolytes and TiO2 nanotubes.