skip to main content

SciTech ConnectSciTech Connect

Title: Water reduction by a p-GaInP2 photoelectrode stabilized by an amorphous TiO2 coating and a molecular cobalt catalyst

Producing hydrogen through solar water splitting requires the coverage of large land areas. Abundant metal-based molecular catalysts offer scalability, but only if they match noble metal activities. We report on a highly active p-GaInP2 photocathode protected through a 35-nm TiO2 layer functionalized by a cobaloxime molecular catalyst (GaInP2-TiO2-cobaloxime). This photoelectrode mediates H2 production with a current density of ~9"0mA"0cm-2 at a potential of 0"0V versus RHE under 1-sun illumination at pH"013. The calculated turnover number for the catalyst during a 20-h period is 139,000, with an average turnover frequency of 1.9"0s-1. Bare GaInP2 shows a rapid current decay, whereas the GaInP2-TiO2-cobaloxime electrode shows </=5% loss over 20"0min, comparable to a GaInP2-TiO2-Pt catalyst particle-modified interface. The activity and corrosion resistance of the GaInP2-TiO2-cobaloxime photocathode in basic solution is made possible by an atomic layer-deposited TiO2 and an attached cobaloxime catalyst.
; ; ; ; ;
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 1476-1122
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nature Materials; Journal Volume: 15; Journal Issue: 4; Related Information: Nature Materials
Nature Publishing Group
Research Org:
NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States))
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
14 SOLAR ENERGY; 77 NANOSCIENCE AND NANOTECHNOLOGY photoelectrochemical; p-GaInP2 photoelectrode; cobaltoxime catalysts; titanium dioxide; stabilization; turnover number; turnover frequency