A Titanium-Doped SiOx Passivation Layer for Greatly Enhanced Performance of a Hematite-Based Photoelectrochemical System

This study introduces an insitu fabrication of nanoporous hematite with a Ti-doped SiOx passivation layer for a high-performance water-splitting system. The nanoporous hematite with a Ti-doped SiOx layer (Ti-(SiOx/np-Fe2O3)) has a photocurrent density of 2.44mAcm-2 at 1.23VRHE and 3.70mAcm-2 at 1.50VRHE. When a cobalt phosphate co-catalyst was applied to Ti-(SiOx/np-Fe2O3), the photocurrent density reached 3.19mAcm-2 at 1.23VRHE with stability, which shows great potential of the use of the Ti-doped SiOx layer with a synergistic effect of decreased charge recombination, the increased number of active sites, and the reduced hole-diffusion pathway from the hematite to the electrolyte.clos