Spontaneous Formation of >90% Optically Transmissive, Electrochemically Active CoP Films for Photoelectrochemical Hydrogen Evolution

Journal Article · Mon Dec 02 00:00:00 EST 2019 · Journal of Physical Chemistry Letters

DOI:https://doi.org/10.1021/acs.jpclett.9b02926· OSTI ID:1633779

Kempler, Paul A. ^[1]; Fu, Harold J. ^[2]; Ifkovits, Zachary P. ^[2]; Papadantonakis, Kimberly M. ^[2]; Lewis, Nathan S. ^[2]

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1. California Institute of Technology (CalTech), Pasadena, CA (United States); California Institute of Technology, Pasadena, CA
2. California Institute of Technology (CalTech), Pasadena, CA (United States)

Earth-abundant catalysts for the hydrogen-evolution reaction need increased mass loadings, relative to Pt films, to achieve comparable activity and stability in acidic electrolytes. We report herein that spontaneous nanostructuring of opaque, electrodeposited CoP films, 40–120 nm in thickness, leads to transparent electrocatalyst films that exhibit up to 90% optical transmission in the visible spectrum. The photocurrent density under simulated sunlight at a representative n⁺p-Si(100)/CoP photocathode increases by 200% after exposure to 0.50 M H₂SO₄(aq) and remains stable for 12 h of continuous operation. Atomic force microscopy and scanning electron microscopy of the film before and after exposure to 0.50 M H₂SO₄(aq) validate an optical model for transparent CoP films as probed with spectroscopic ellipsometry.

• Research Organization: California Institute of Technology (CalTech), Pasadena, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: SC0004993
• OSTI ID: 1633779
• Journal Information: Journal of Physical Chemistry Letters, Journal Name: Journal of Physical Chemistry Letters Journal Issue: 1 Vol. 11; ISSN 1948-7185
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY