Front-Surface Potential of Platinized <i>p</i> -InP Photocathodes Probed by Dual-Working-Electrode Measurements
The front-surface potential (<i>E</i> <sub>fr</sub>) of <i>p</i>-InP/Pt photocathodes performing the hydrogen-evolution reaction has been probed under operating conditions using a dual-working-electrode (DWE) method. The DWE data are consistent with expectations for proposed stability mechanisms for <i>p</i>-InP photocathodes. Specifically, <i>E</i> <sub>fr</sub> for Pt-modified <i>p</i>-InP adopts a value near the reversible hydrogen electrode (RHE) potential, consistent with kinetic suppression of metallic In<sup>0</sup> formation. The data provide a rapid, operando metric of interfacial catalyst activity, and indicate that <i>E</i> <sub>fr</sub> for the <i>p</i>-InP/Pt junction is governed by surface catalytic kinetics rather than by the applied back-contact potential (<i>E</i> <sub>b</sub>).
Authors
- Weilai Yu (ORCID: https://orcid.org/0000-0002-9420-0702)
- Nathan S. Lewis (ORCID: https://orcid.org/0000-0001-5245-0538)
Institutions
- California Institute of Technology (US)
- University of Toronto (CA)
- NOAA Chemical Sciences Laboratory (US)
Publication Details
- Journal
- ACS Energy Letters
- Published
- 2026-01-19
- DOI
- https://doi.org/10.1021/acsenergylett.5c04153
- Primary Topic
- Photocathodes and Microchannel Plates
- Type
- article
- Field-Weighted Citation Impact
- 0.00