Abstract
The electrocatalytic performance for hydrogen evolution has been evaluated for radial-junction n+p-Si microwire (MW) arrays with Pt or cobalt phosphide, CoP, nanoparticulate catalysts in contact with 0.50 M H2SO4(aq). The CoP-coated (2.0 mg cm-2) n+p-Si MW photocathodes were stable for over 12 h of continuous operation and produced an open-circuit photovoltage (Voc) of 0.48 V, a light-limited photocurrent density (Jph) of 17 mA cm-2, a fill factor (ff) of 0.24, and an ideal regenerative cell efficiency (IRC) of 1.9% under simulated 1 Sun illumination. Pt-coated (0.5 mg cm-2) n+p-Si MW-array photocathodes produced Voc = 0.44 V, Jph = 14 mA cm-2, ff = 0.46, and = 2.9% under identical conditions. Thus, the MW geometry allows the fabrication of photocathodes entirely comprised of earth-abundant materials that exhibit performance comparable to that of devices that contain Pt.
Original language | English |
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Pages (from-to) | 1679-1683 |
Number of pages | 5 |
Journal | Journal of Physical Chemistry Letters |
Volume | 6 |
Issue number | 9 |
DOIs | |
Publication status | Published - May 7 2015 |
Keywords
- cobalt phosphide
- hydrogen evolution
- microwires
- platinum
- silicon
- solar fuel
ASJC Scopus subject areas
- Materials Science(all)
- Physical and Theoretical Chemistry