Monitoring the Structure Evolution of Titanium Oxide Photocatalysts: From the Molecular Form via the Amorphous State to the Crystalline Phase

Ezgi Onur Şahin, Yitao Dai, Candace K. Chan, Harun Tüysüz, Wolfgang Schmidt, Joohyun Lim, Siyuan Zhang, Christina Scheu, Claudia Weidenthaler

Research output: Contribution to journalArticlepeer-review

Abstract

Amorphous TixOy with high surface area has attracted significant interest as photocatalyst with higher activity in ultraviolet (UV) light-induced water splitting applications compared to commercial nanocrystalline TiO2. Under photocatalytic operation conditions, the structure of the molecular titanium alkoxide precursor rearranges upon hydrolysis and leads to higher connectivity of the structure-building units. Structurally ordered domains with sizes smaller than 7 Å form larger aggregates. The experimental scattering data can be explained best with a structure model consisting of an anatase-like core and a distorted shell. Upon exposure to UV light, the white TixOy suspension turns dark corresponding to the reduction of Ti4+ to Ti3+ as confirmed by electron energy loss spectroscopy (EELS). Heat-induced crystallisation was followed by in situ temperature-dependent total scattering experiments. First, ordering in the Ti−O environment takes place upon to 350 °C. Above this temperature, the distorted anatase core starts to grow but the structure obtained at 400 °C is still not fully ordered.

Original languageEnglish (US)
Pages (from-to)11600-11608
Number of pages9
JournalChemistry - A European Journal
Volume27
Issue number45
DOIs
StatePublished - Aug 11 2021

Keywords

  • PDF (pair distribution function)
  • crystallization
  • nanoparticles
  • photocatalysis
  • reduced titania

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

Fingerprint

Dive into the research topics of 'Monitoring the Structure Evolution of Titanium Oxide Photocatalysts: From the Molecular Form via the Amorphous State to the Crystalline Phase'. Together they form a unique fingerprint.

Cite this