Carbon-layer-protected cuprous oxide nanowire arrays for efficient water reduction

Zhonghai Zhang, Rubal Dua, Lianbin Zhang, Haibo Zhu, Hongnan Zhang, Peng Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

300 Citations (Scopus)

Abstract

In this work, we propose a solution-based carbon precursor coating and subsequent carbonization strategy to form a thin protective carbon layer on unstable semiconductor nanostructures as a solution to the commonly occurring photocorrosion problem of many semiconductors. A proof-of-concept is provided by using glucose as the carbon precursor to form a protective carbon coating onto cuprous oxide (Cu2O) nanowire arrays which were synthesized from copper mesh. The carbon-layer-protected Cu2O nanowire arrays exhibited remarkably improved photostability as well as considerably enhanced photocurrent density. The Cu2O nanowire arrays coated with a carbon layer of 20 nm thickness were found to give an optimal water splitting performance, producing a photocurrent density of -3.95 mA cm-2 and an optimal photocathode efficiency of 0.56% under illumination of AM 1.5G (100 mW cm-2). This is the highest value ever reported for a Cu 2O-based electrode coated with a metal/co-catalyst-free protective layer. The photostability, measured as the percentage of the photocurrent density at the end of 20 min measurement period relative to that at the beginning of the measurement, improved from 12.6% on the bare, nonprotected Cu2O nanowire arrays to 80.7% on the continuous carbon coating protected ones, more than a 6-fold increase. We believe that the facile strategy presented in this work is a general approach that can address the stability issue of many nonstable photoelectrodes and thus has the potential to make a meaningful contribution in the general field of energy conversion.

Original languageEnglish
Pages (from-to)1709-1717
Number of pages9
JournalACS Nano
Volume7
Issue number2
DOIs
Publication statusPublished - 26 Feb 2013
Externally publishedYes

Keywords

  • carbon layer
  • cuprous oxide
  • nanowire
  • photocathode
  • photocorrosion
  • water splitting

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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