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Published January 9, 2013 | Published + Supplemental Material
Journal Article Open

Hydrogen Evolution from Pt/Ru-Coated p-Type WSe_2 Photocathodes

Abstract

Crystalline p-type WSe_2 has been grown by a chemical vapor transport method. After deposition of noble metal catalysts, p-WSe_2 photocathodes exhibited thermodynamically based photoelectrode energy-conversion efficiencies of >7% for the hydrogen evolution reaction under mildly acidic conditions, and were stable under cathodic conditions for at least 2 h in acidic as well as in alkaline electrolytes. The open circuit potentials of the photoelectrodes in contact with the H^(+)/H_2 redox couple were very close to the bulk recombination/diffusion limit predicted from the Shockley diode equation. Only crystals with a prevalence of surface step edges exhibited a shift in flat-band potential as the pH was varied. Spectral response data indicated effective minority-carrier diffusion lengths of ~1 μm, which limited the attainable photocurrent densities in the samples to ~15 mA cm^(–2) under 100 mW cm^(–2) of Air Mass 1.5G illumination.

Additional Information

© 2012 American Chemical Society. Received: August 29, 2012; published: November 30, 2012. This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC0004993. The contributions from JRM and HBG were supported by CCSER (the Gordon and Betty Moore Foundation). JRM is supported by a graduate research fellowship from the Office of Science of the U.S. Department of Energy.

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Published - ja308581g.pdf

Supplemental Material - ja308581g_si_001.pdf

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Created:
August 19, 2023
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October 23, 2023