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Structural defects cause TiO2-based photocatalysts to be active in visible light
Igor N Martyanov1, Sitharaman Uma, Shalini Rodrigues
1Department of Chemistry, Kansas State University, 111 Willard Hall, Manhattan, Kansas 66506, USA.
Chemical Communications (Cambridge, England)
|October 30, 2004
Summary
Oxygen defects in titanium dioxide (TiO2) are crucial for enhancing its visible light activity. Using TiO or Ti2O3 as precursors yields superior TiO2 for visible light applications compared to TiN.
Area of Science:
- Materials Science
- Photocatalysis
- Solid-State Chemistry
Background:
- Titanium dioxide (TiO2) is a widely studied semiconductor photocatalyst.
- Extending the photoactivity of TiO2 to the visible light spectrum is a key research objective.
- The role of defects in modulating semiconductor properties is of significant interest.
Purpose of the Study:
- To investigate the influence of precursor materials on the visible light activity of TiO2.
- To understand the role of oxygen defects/vacancies in enhancing TiO2's visible light response.
Main Methods:
- Synthesis of TiO2 by oxidizing different titanium precursors (TiO, Ti2O3, TiN).
- Characterization of the resulting TiO2 materials.
- Evaluation of photocatalytic activity under visible light irradiation.
Main Results:
- TiO2 derived from TiO or Ti2O3 exhibited significantly higher visible light activity compared to TiO2 derived from TiN.
- The enhanced activity is attributed to the presence of oxygen defects/vacancies in the TiO2 structure.
- Precursor choice critically impacts the defect concentration and subsequent photocatalytic performance.
Conclusions:
- Oxygen defects/vacancies are essential for extending the photocatalytic activity of TiO2 into the visible light region.
- TiO and Ti2O3 are more suitable precursors than TiN for synthesizing visible-light-active TiO2.
- Controlled introduction of oxygen vacancies is a promising strategy for developing advanced TiO2 photocatalysts.