Oxygen Deficient TiO₂ Photoanode for Photoelectrochemical Water Oxidation

Abstract:

Titanium dioxide (TiO₂) has been widely used as photoanodes in photoelectrochemical (PEC) water splitting. However, the typically high density of bandgap trap states results in fast charge carrier recombination and poor electrical conductivity, and thereby weak PEC performance. Rational creation of oxygen vacancy (V_o) in TiO₂ has been demonstrated as an effective method to modify the electronic and optical properties, as well as improved PEC performance. Different strategies have been developed to fabricate oxygen deficient TiO₂ photoanodes, such as hydrogen treatment, thermal annealing, electrochemical reduction, flame reduction, and chemical reduction. In conjunction with oxygen vacancy creation, doping of TiO₂ with elements further enhances the PEC activity by introducing other bandgap states. Various techniques, including ultrafast laser spectroscopy, have been employed to probe the chemical nature and associated charge carrier dynamics of the bandgap states.

• Periodical: Solid State Phenomena (Volume 253)
• Pages: 11-40
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.253.11
• Online since: August 2016
• Authors: Yi Yang, Ying Chih Pu, Yat Li, Jin Zhang*
• Keywords: Defect Chemistry, Photoelectrodes, Water Oxidation

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