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Published September 23, 2014 | public
Journal Article

Comparison between the measured and modeled hydrogen-evolution activity of Ni- or Pt-coated silicon photocathodes

Abstract

The electrocatalytic behavior of Ni and Pt nanoparticles for the hydrogen-evolution reaction (HER) on p-type Si photocathodes was measured experimentally and the current density vs. potential (J–E) characteristics of a general metal catalyst on p-Si was modeled as a combination of a Si photodiode in series electrically with metal electrocatalysts. Relative to the rest potential, the J–E characteristics produced by the model showed an increase in total overpotential required to reach a specified current density for the metallized photoelectrodes relative to that of a metal electrode. This prediction was in accord with the experimentally observed behavior of Pt on p-Si, but was in contrast to the behavior observed for Ni on p-Si. Properly accounting for junction energetics and kinetics of the HER is critical to accurate predictions of the solar-to-hydrogen (STH) energy-conversion efficiency of metallized integrated photoelectrochemical systems. Further, models that accurately predict the performance of metal catalysts on semiconductor light absorbers are required to optimize the catalytic performance of metallized photoelectrodes.

Additional Information

© 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. Received 10 October 2013; Received in revised form 19 December 2013; Accepted 24 December 2013; Available online 13 April 2014. 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. JRM acknowledges graduate research fellowship support from the U.S. Department of Energy, Office of Science. Research was in part carried out at the Molecular Materials Research Center of the Beckman Institute of the California Institute of Technology. Z.H. thanks Prof. Steve Maldonado, Joseph Beardslee, Heather Audesirk and Craig Wiggenhorn for their assistance with the experiments and for helpful discussions.

Additional details

Created:
August 22, 2023
Modified:
October 26, 2023