Modulation of the Reduction Potential of TiO2- x by Fluorination for Efficient and Selective CH4 Generation from CO2 Photoreduction

Mingyang Xing, Yi Zhou, Chunyang Dong, Lejuan Cai, Lixi Zeng, Bin Shen, Lihan Pan, Chencheng Dong, Yang Chai, Jinlong Zhang, Yadong Yin

Research output: Journal article publicationJournal articleAcademic researchpeer-review

102 Citations (Scopus)

Abstract

Photocatalytic reduction of CO2 holds great promises for addressing both the environmental and energy issues that are facing the modern society. The major challenge of CO2 photoreduction into fuels such as methane or methanol is the low yield and poor selectivity. Here, we report an effective strategy to enhance the reduction potential of photoexcited electrons by fluorination of mesoporous single crystals of reduced TiO2-x. Density functional theory calculations and photoelectricity tests indicate that the Ti3+ impurity level is upswept by fluorination, owing to the built-in electric field constructed by the substitutional F that replaces surface oxygen vacancies, which leads to the enhanced reduction potential of photoexcited electrons. As a result, the fluorination of the reduced TiO2-x dramatically increases the CH4 production yield by 13 times from 0.125 to 1.63 μmol/g·h under solar light illumination with the CH4 selectivity being improved from 25.7% to 85.8%. Our finding provides a metal-free strategy for the selective CH4 generation from CO2 photoreduction.

Original languageEnglish
Pages (from-to)3384-3390
Number of pages7
JournalNano Letters
Volume18
Issue number6
DOIs
Publication statusPublished - 13 Jun 2018

Keywords

  • CO photoreduction
  • fluorination
  • mesoporous single crystal
  • Photocatalysis
  • semiconductors

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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