Premium
Tuning the Surface Structure of Nitrogen‐Doped TiO 2 Nanofibres—An Effective Method to Enhance Photocatalytic Activities of Visible‐Light‐Driven Green Synthesis and Degradation
Author(s) -
Zheng Zhanfeng,
Zhao Jian,
Yuan Yong,
Liu Hongwei,
Yang Dongjiang,
Sarina Sarina,
Zhang Hongjie,
Waclawika Eric R.,
Zhu Huaiyong
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201203961
Subject(s) - photocatalysis , materials science , phenylacetylene , adsorption , anatase , calcination , chemical engineering , visible spectrum , nanoparticle , photochemistry , nanotechnology , catalysis , chemistry , organic chemistry , optoelectronics , engineering
Nitrogen‐doped TiO 2 nanofibres of anatase and TiO 2 (B) phases were synthesised by a reaction between titanate nanofibres of a layered structure and gaseous NH 3 at 400–700 °C, following a different mechanism than that for the direct nitrogen doping from TiO 2 . The surface of the N‐doped TiO 2 nanofibres can be tuned by facial calcination in air to remove the surface‐bonded N species, whereas the core remains N doped. N‐Doped TiO 2 nanofibres, only after calcination in air, became effective photocatalysts for the decomposition of sulforhodamine B under visible‐light irradiation. The surface‐oxidised surface layer was proven to be very effective for organic molecule adsorption, and the activation of oxygen molecules, whereas the remaining N‐doped interior of the fibres strongly absorbed visible light, resulting in the generation of electrons and holes. The N‐doped nanofibres were also used as supports of gold nanoparticle (Au NP) photocatalysts for visible‐light‐driven hydroamination of phenylacetylene with aniline. Phenylacetylene was activated on the N‐doped surface of the nanofibres and aniline on the Au NPs. The Au NPs adsorbed on N‐doped TiO 2 (B) nanofibres exhibited much better conversion (80 % of phenylacetylene) than when adsorbed on undoped fibres (46 %) at 40 °C and 95 % of the product is the desired imine. The surface N species can prevent the adsorption of O 2 that is unfavourable for the hydroamination reaction, and thus, improve the photocatalytic activity. Removal of the surface N species resulted in a sharp decrease of the photocatalytic activity. These photocatalysts are feasible for practical applications, because they can be easily dispersed into solution and separated from a liquid by filtration, sedimentation or centrifugation due to their fibril morphology.