Abstract
Mesoporous NiO photocathodes containing the push-pull dye PB6 and alkyl-derivatized cobaloxime catalysts were prepared using surface amide couplings and analyzed for photocatalytic proton reduction catalysis. The length of the alkyl linker used to derivatize the cobalt catalysts was found to correlate to the photocurrent with the highest photocurrent observed using shorter alkyl linkers but the lowest one for samples without linker. The alkyl linkers were also helpful in slowing dye-NiO charge recombination. Photoelectrochemical measurements and femtosecond transient absorption spectroscopic measurements suggested electron transfer to the surface-immobilized catalysts occurred; however, H2 evolution was not observed. Based on UV-vis, X-ray fluorescence spectroscopy (XRF), and X-ray photoelectron spectroscopy (XPS) measurements, the cobalt catalyst appeared to be limiting the photocathode performance mainly via cobalt demetallation from the oxime ligand. This study highlights the need for a deeper understanding of the effect of catalyst molecular design on photocathode performance.
Original language | English |
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Pages (from-to) | 31372-31381 |
Number of pages | 10 |
Journal | ACS Applied Materials and Interfaces |
Volume | 12 |
Issue number | 28 |
DOIs | |
Publication status | Published - Jul 15 2020 |
Keywords
- cobaloxime
- cobalt
- nickel oxide
- photocathode
- solar fuels
ASJC Scopus subject areas
- Materials Science(all)