Revealing the Semiconductor-Catalyst Interface in Buried Platinum Black Silicon Photocathodes

Nathan Neale, Nicholas Anderson, Jeffery Aguiar

Research output: Contribution to journalArticlepeer-review

15 Scopus Citations

Abstract

Nanoporous "black" silicon semiconductors interfaced with buried platinum nanoparticle catalysts have exhibited stable activity for photoelectrochemical hydrogen evolution even after months of exposure to ambient conditions. The mechanism behind this stability has not been explained in detail, but is thought to involve a Pt/Si interface free from SiOx layer that would adversely affect interfacial charge transfer kinetics. In this paper, we resolve the chemical composition and structure of buried Pt/Si interfaces in black silicon photocathodes from a micron to sub-nanometer level using aberration corrected analytical scanning transmission electron microscopy. Through a controlled electrodeposition of copper on samples aged for one month in ambient conditions, we demonstrate that the main active catalytic sites are the buried Pt nanoparticles located below the 400-800 nm thick nanoporous SiOx layer. Though hydrogen production performance degrades over 100 h under photoelectrochemical operating conditions, this burying strategy preserves an atomically clean catalyst/Si interface free of oxide or other phases under air exposure and provides an example of a potential method for stabilizing silicon photoelectrodes from oxidative degradation in photoelectrochemical applications.

Original languageAmerican English
Pages (from-to)8123-8129
Number of pages7
JournalJournal of Materials Chemistry A
Volume4
Issue number21
DOIs
StatePublished - 2016

Bibliographical note

Publisher Copyright:
© The Royal Society of Chemistry 2016.

NREL Publication Number

  • NREL/JA-5900-65024

Keywords

  • photocatalysis
  • solar-photochemistry
  • water splitting

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