Fluorine-Doped Porous Single-Crystal Rutile TiO2 Nanorods for Enhancing Photoelectrochemical Water Splitting

Fluorine-doped hierarchical porous single-crystal rutile TiO2 nanorods have been synthesized through a silica template method, in which F- ions acts as both n-type dopants and capping agents to make the isotropic growth of the nanorods. The combination of high crystallinity, abundant surface reactive sites, large porosity, and improved electronic conductivity leads to an excellent photoelectrochemical activity. The photoanode made of F-doped porous single crystals displays a remarkably enhanced solar-to-hydrogen conversion efficiency (approximate to 0.35% at -0.33 V vs. Ag/AgCl) under 100 mWcm(-2) of AM=1.5 solar simulator illumination that is ten times of the pristine solid TiO2 single crystals.