Abstract
Molecular cobalt-containing hydrogen production catalysts are grafted to a visible-light-absorbing semiconductor. The attachment procedure exploits the UV-induced immobilization chemistry of vinylpyridine to p-type (100) gallium phosphide (GaP). Single step surface-initiated photopolymerization yields a covalently attached polymer with pendent pyridyl groups that provide attachment points for assembling cobaloxime catalysts. Successful attachment is characterized by grazing angle attenuated total reflection Fourier transform infrared spectroscopy (GATR-FTIR), which shows distinct vibrational modes associated with the catalyst, as well as X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure spectroscopy (XANES) that confirm the presence of intact CoIII complex on the surface. The Co-functionalized photocathode shows significantly enhanced photoelectrochemical (PEC) performance in aqueous conditions at neutral pH, compared to results obtained on GaP without attached cobalt complex. PEC measurements, at 100 mW cm-2 illumination, yield a 2.4 mA cm-2 current density at a 310 mV underpotential.
Original language | English (US) |
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Pages (from-to) | 11861-11868 |
Number of pages | 8 |
Journal | Journal of the American Chemical Society |
Volume | 135 |
Issue number | 32 |
DOIs | |
State | Published - Aug 14 2013 |
Externally published | Yes |
ASJC Scopus subject areas
- Catalysis
- General Chemistry
- Biochemistry
- Colloid and Surface Chemistry