Enhanced charge separation and oxidation kinetics by loading Pt nanoparticles with hydrogenated TiO2 nanotubes

Charge separation and oxidation kinetics are both critical for solar energy conversion in photoelectrochemical cell, but it is difficult to enhance simultaneously by a semiconductor. Here, the hydrogenated TiO 2 loaded by Pt nanoparticles with improved charge separation and oxidation kinetics photoanodes are developed, characterized, and tested. The TiO 2 nanotubes are prepared by hydrothermal of Ti foils and used as substrates for hydrogenation and loaded by Pt through photodeposition. Ascribe to the synergetic of hydroxylated surface and Pt nanoparticles, the photocurrent of Pt/H:TiO 2 is enhanced from 0.052 (TiO 2 ) to 0.098 mA/cm 2 at 1.0 V versus RHE for water oxidation and almost increased 1.3 times for sulfite oxidation. Further, the electrons’ transport time has been reduced 20%, and the incident photon-to-electron conversion efficiency for Pt/H:TiO 2 has been increased by 2.5-fold for water oxidation under 350 nm illumination at 1.0 V versus RHE. The charge separation and oxidation kinetics efficiencies of Pt/H:TiO 2 are improved to 62.2 and 39.9% compared with pristine TiO 2 (54.2 and 27.6%) at 1.0 V versus RHE. The origin of the enhanced photoelectrochemical performances for Pt/H:TiO 2 is due to the hydroxylated surface and the absorption of plasmon resonance by Pt nanoparticles.