Probing the charge separation process on In2S3/Pt-TiO2 nanocomposites for boosted visible-light photocatalytic hydrogen production

Fenglong Wang, Zuanming Jin, Yijiao Jiang, Ellen H. G. Backus, Mischa Bonn, Shi Nee Lou, Dmitry Turchinovich, Rose Amal

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

A simple refluxing wet-chemical approach is employed for fabricating In2S3/Pt-TiO2 heterogeneous catalysts for hydrogen generation under visible light irradiation. When the mass ratio between Pt-TiO2 and cubic-phased In2S3 (denoted as In2S3/Pt-TiO2) is two, the composite catalyst shows the highest hydrogen production, which exhibits an 82-fold enhancement over in-situ deposited Pt-In2S3. UV-vis diffuse reflectance and valence band X-ray photoelectron spectra elucidate that the conduction band of In2S3 is 0.3 eV more negative compared to that of TiO2, favouring charge separation in the nanocomposites. Photoelectrochemical transient photo-current measurements and optical pump - terahertz probe spectroscopic studies further corroborate the charge separation in In2S3/Pt-TiO2. The migration of photo induced electrons from the In2S3 conduction band to the TiO2 conduction band and subsequently into the Pt nanoparticles is found to occur within 5 ps. Based on the experimental evidence, a charge separation process is proposed which accounts for the enhanced activity exhibited by the In2S3/Pt-TiO2 composite catalysts.

Original languageEnglish
Pages (from-to)25-31
Number of pages7
JournalApplied Catalysis B: Environmental
Volume198
DOIs
Publication statusPublished - 5 Dec 2016

Keywords

  • Hydrogen generation
  • In2S3/Pt-TiO2
  • Visible-light photocatalysis
  • Charge transfer and separation
  • Optical pump-terahertz probe spectroscopy

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