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

Sisir Yalamanchili, Paul A. Kempler, Kimberly M. Papadantonakis, Harry A. Atwater, Nathan S. Lewis

Research output: Contribution to journalArticle

2 Citations (Scopus)


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 H2 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 H2 production from 0.50 M H2SO4(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 H2SO4(aq).

Original languageEnglish
Pages (from-to)2217-2236
Number of pages20
JournalSustainable Energy and Fuels
Issue number9
Publication statusPublished - Jan 1 2019


ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Energy Engineering and Power Technology

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