Conductive, amorphous TiO2 coatings deposited by atomic-layer deposition, in combination with a sputter deposited NiCrOx oxygen-evolution catalyst, have been used to protect Si microwire arrays from passivation or corrosion in contact with aqueous electrolytes. Coated np+-Si/TiO2/NiCrOx as well as heterojunction n-Si/TiO2/NiCrOx Si microwire-array photoanodes exhibited stable photoelectrochemical operation in aqueous ferri-/ferro-cyanide solutions. The coatings also allowed for photoanodic water oxidation in 1.0 M KOH(aq) solutions for >2200 h of continuous operation under simulated 1 Sun conditions with ∼100% Faradaic efficiency for the evolution of O2(g).
ASJC Scopus subject areas
- Environmental Chemistry
- Renewable Energy, Sustainability and the Environment
- Nuclear Energy and Engineering