Improvement of Photoelectrochemical Properties by Surface Modification with Iron Oxide on p-Type Si Electrodes for Hydrogen Evolution from Water

摘要

Surface modifications using platinum (Pt) particles and iron oxides (FeO_x) were found to lead to a significant improvement in the current-potential (J-E) properties for hydrogen evolution from water in p-type silicon (p-Si) electrodes. The onset potential and cathodic photocurrent for hydrogen evolution from the Pt/p-Si(100) electrode were, respectively, 0.50 VRHe and 0.28mA/cm~2 at 0 Vrhe (RHE: reversible hydrogen electrode). When the p-Si(100) electrode was coated with iron oxide followed by Pt particles [Pt/FeOx/p-Si(100)], it showed an onset potential and photocurrent of 0.85 Vrhe and 2.45mA/cm~2 at OVrhe, respectively. A detailed study of surface morphology and a comparative study between (100) plane and (111) plane p-Si electrodes revealed that the dramatic improvement in J-E properties was the result of a change in the surface structure and tailing of Fed* in p-Si.