Directing photocatalytic and photoelectrocatalytic performance of TiO2 by using TEA and NH4F as doping precursors

作者：Leonardo Castellanos Leal Edgar; Acevedo Pena Prospero^*; Lartundo Rojas Luis; Maria Cordoba Tuta Elcy

来源：Journal of Sol-Gel Science and Technology, 2016, 80(2): 462-473.

DOI：10.1007/s10971-016-4135-8

• Codoped TiO2
• Nonmetallic doping
• Photocatalysis
• Photoelectrocatalysis

Triethylamine (TEA) and NH4F-modified TiO2 powders and thin films were prepared by combining sol-gel and hydrothermal processes. Modification with TEA results in increased specific surface area and induces energy states below the conduction band of TiO2. On the other hand, the use of NH4F decreases the band-gap, displacing the valence band. Employing radical-scavenging agents, it was found that formation of O (2) (*) is preferred in TEA-modified TiO2, whereas generation of both O (2) (*) and OH* results from simultaneous modification. Furthermore, the photocatalytic degradation rate was directly proportional to their specific surface area. However, this trend was reversed in a photoelectrocatalytic cell, due to the fact that the photogenerated electrons are rapidly transported to the rear contact, which restrains their transfer to the dissolved oxygen to generate O (2) (*) . Therefore, the presence of OH* radicals and direct charge transfer processes appears to play a key role in the photoelectrocatalytic process.

• 出版日期2016-11