Morphology-oriented urchin-like TiO2 nanostructures for enhanced photoelectrochemical water splitting

Abstract

In this work, urchin-like TiO2 (u-TiO2) nanostructures were grown on Ti sheets in an alkaline media by facile hydrothermal method in the presence of triethanolamine (TEOA). u-TiO2 nanostructures were synthesized under the optimized experimental conditions with hydrothermal method in a solution containing 1.5 M NaOH and 0.5 M TEOA at 180 ºC for 6 h. TEOA with \(\ddot{\text{N}}\)- functional group acts as a ligand for hydrated Ti4+ cations and decorates u-TiO2 at the surface of substrate. Under UV-irradiation, the obtained photocurrent density for u-TiO2 photoanodes was 1.6 mAcm− 2 under the voltage bias of 0.5 V. Finally, CdS-sensitized u-TiO2 photoanode was prepared by a successive ionic layer adsorption and reaction (SILAR) method to sensitize u-TiO2 with CdS nanoparticles under visible light irradiation. The obtained Z-scheme u-TiO2/CdS heterojunction photoanode showed the photocurrent density of 8.5 mAcm− 2 under AM1.5G light irradiation.