Enhanced intrinsic photocatalytic activity of TiO 2 electrospun nanofibers based on temperature assisted manipulation of
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jinyan Qi and Yuan Fang School of Materials Science and Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
Jianfeng Xu and Chunmei Zhoua) State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China
Zhengguo Jin School of Materials Science and Engineering, Tianjin University, Tianjin 300072, People’s Republic of China
Zhanglian Hong, Mingjia Zhi, and Yi Liu State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China (Received 24 May 2016; accepted 2 August 2016)
TiO2 nanofibers (TNFs) with different anatase/rutile phase ratios were fabricated using electrospinning technique followed by the annealing at different temperatures. The effect of annealing temperatures on their morphology, structural, and optical properties and photocatalytic activity was investigated. The photocatalytic performance of TNFs was evaluated by degradation of methyl orange (MO) in aqueous solution under the irradiation of simulated solar light. Annealing temperature significantly influenced photocatalytic degradation of MO due to the incorporation of rutile phase which suppresses recombination of photoactivated electron and hole pairs. Turnover frequency (TOF) of MO degradation was introduced to describe the intrinsic activity of TNFs. TNFs acquired best anatase/rutile phase ratio (A/R 5 83/17) when annealed at 650 °C, resulting in highest TOF value 2394 h1, two times higher as compared to P25 with similar anatase/rutile phase ratio (A/R 5 85/15). Appropriate crystalline structure could be the reason for good photocatalytic activity as well as intrinsic activity of TNFs.
I. INTRODUCTION
The beginning of TiO2 photocatalysis was in the early seventies when Honda and Fujishima reported the decomposition of water to hydrogen on the surface of TiO2 electrodes under light irradiation.1 Recently, a combined effect of growing population and a rapidly developing industry has resulted in a steady increase of water pollution in many parts of the world due to the accelerated release of harmful agents.2 During past few decades, photocatalysis has emerged as a potential candidate to overcome the environmental pollutants remedy and have been potentially applied for the mineralization of organic pollutants, disinfection of water and air, water-splitting, production of renewable fuels and organic synthesis.3 Few metal oxides including ZnO, CeO2, WO3, and ZrO2 Contributing Editor: Xiaobo Chen a) Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/jmr.2016.309
have also been investigated for the effective removal of industrial pollutants and waste water treatment.4–7 However, titanium dioxide has been investigated as the best known and most widely used photocatalyst owing to its low cost, less toxicity, high stability, and photocatalytic activity.8,9 Anatase, rutile, brookite, and TiO2 (B) are the four main crystalline pha
