Photoelectrochemical Hydrogen Production of TiO2 Passivated Pt/Si-Nanowire Composite Photocathode

摘要

Si nanowire (SiNW) arrays decorated with Pt nanoparticles are passivated with TiO2 surface layer using atomic layer deposition (ALD). The sandwich structure TiO2/Pt/SiNW shows superior photoelectrochemical performance to the control planar silicon electrodes, especially under the concentrated solar radiation. Pt nanoparticles separated from aqueous electrolyte by TiO2 layer of more than 15 nm still well catalyze surface photoelectrochemical hydrogen production without direct contact to the electrolyte. This structural configuration shows remarkable chemical stability and anodically shifted onset potential, suggesting great promise for applications in solar hydrogen production. The maximum photon-to-energy reaches 15.6%. conversion efficiency of the TiO2/Pt/SiNW