Microwave-assisted self-doping of TiO2 photonic crystals for efficient photoelectrochemical water splitting

Zhonghai Zhang, Xiulin Yang, Mohamed Nejib Hedhili, Elaf Ahmed, Le Shi, Peng Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

84 Citations (Scopus)

Abstract

In this article, we report that the combination of microwave heating and ethylene glycol, a mild reducing agent, can induce Ti3+ self-doping in TiO2. A hierarchical TiO2 nanotube array with the top layer serving as TiO2 photonic crystals (TiO2 NTPCs) was selected as the base photoelectrode. The self-doped TiO2 NTPCs demonstrated a 10-fold increase in visible-light photocurrent density compared to the nondoped one, and the optimized saturation photocurrent density under simulated AM 1.5G illumination was identified to be 2.5 mA cm-2 at 1.23 V versus reversible hydrogen electrode, which is comparable to the highest values ever reported for TiO2-based photoelectrodes. The significant enhancement of photoelectrochemical performance can be ascribed to the rational coupling of morphological and electronic features of the self-doped TiO 2 NTPCs: (1) the periodically morphological structure of the photonic crystal layer traps broadband visible light, (2) the electronic interband state induced from self-doping of Ti3+ can be excited in the visible-light region, and (3) the captured light by the photonic crystal layer is absorbed by the self-doped interbands.

Original languageEnglish
Pages (from-to)691-696
Number of pages6
JournalACS Applied Materials and Interfaces
Volume6
Issue number1
DOIs
Publication statusPublished - 8 Jan 2014
Externally publishedYes

Keywords

  • photoelectrochemical
  • photonic crystal
  • self-doping
  • TiO nanotube
  • water splitting

ASJC Scopus subject areas

  • Materials Science(all)

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