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Integration of electrocatalysts with silicon microcone arrays for minimization of optical and overpotential losses during sunlight-driven hydrogen evolution

Yalamanchili, Sisir and Kempler, Paul A. and Papadantonakis, Kimberly M. and Atwater, Harry A. and Lewis, Nathan S. (2019) Integration of electrocatalysts with silicon microcone arrays for minimization of optical and overpotential losses during sunlight-driven hydrogen evolution. Sustainable Energy and Fuels, 3 (9). pp. 2227-2236. ISSN 2398-4902. doi:10.1039/c9se00294d.

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Microstructured photoelectrode morphologies can advantageously facilitate integration of optically absorbing electrocatalysts with semiconducting light absorbers, to maintain low overpotentials for fuel production without producing a substantial loss in photocurrent density. We report herein the use of arrays of antireflective, high-aspect-ratio Si microcones (μ-cones), coupled with light-blocking Pt and Co–P catalysts, as photocathodes for H_2 evolution. Thick (∼16 nm) layers of Pt or Co–P deposited onto Si μ-cone arrays yielded absolute light-limited photocurrent densities of ∼32 mA cm^(−2), representing a reduction in light-limited photocurrent density of 6% relative to bare Si μ-cone-array photocathodes, while maintaining high fill factors and low overpotentials for H_2 production from 0.50 M H_2SO_4(aq). The Si μ-cone arrays were embedded in a flexible polymeric membrane and removed from the Si substrate, to yield flexible photocathodes consisting of polymer-embedded arrays of free-standing μ-cones that evolved hydrogen from 0.50 M H_2SO_4(aq).

Item Type:Article
Related URLs:
URLURL TypeDescription Information
Kempler, Paul A.0000-0003-3909-1790
Papadantonakis, Kimberly M.0000-0002-9900-5500
Atwater, Harry A.0000-0001-9435-0201
Lewis, Nathan S.0000-0001-5245-0538
Additional Information:© The Royal Society of Chemistry 2019. Received 10th May 2019. Accepted 13th May 2019. This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, as follows: electrochemical measurements for all devices, and fabrication of p-Si/Co–P devices was supported through the Office of Science of the U.S. Department of Energy under Award No. DE-SC0004993; the development and fabrication of p-Si and n^+p-Si/Pt μ-cone arrays and reflection measurements were supported by the National Science Foundation (NSF) under NSF CA No. EEC-1041895. Additional support for this work was provided by the Lockheed Martin Corporation (Award 4103810021). Fabrication of Si μ-cones was performed in the Kavli Nanoscience Institute (KNI) at Caltech, and we thank the KNI staff for their assistance during fabrication.
Group:JCAP, Kavli Nanoscience Institute
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0004993
Lockheed Martin4103810021
Issue or Number:9
Record Number:CaltechAUTHORS:20190531-151359075
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:96018
Deposited By: George Porter
Deposited On:31 May 2019 22:22
Last Modified:16 Nov 2021 17:17

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