Chinese Journal of Catalysis ›› 2020, Vol. 41 ›› Issue (1): 50-61.DOI: 10.1016/S1872-2067(19)63424-8

• Photocatalytic H2 production • Previous Articles     Next Articles

Hydrogen producing water treatment through mesoporous TiO2 nanofibers with oriented nanocrystals

Guocheng Huanga,b, Xueyan Liua, Shuangru Shia, Sitan Lia, Zhengtao Xiaoa, Weiqian Zhena, Shengwei Liua, Po Keung Wongb,c   

  1. a School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, Guangdong, China;
    b School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China;
    c Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China
  • Received:2019-04-12 Revised:2019-06-05 Online:2020-01-18 Published:2019-10-22
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (21707173, 51872341, 51572209), the Science and Technology Program of Guangzhou (201707010095), the Start-up Funds for High-Level Talents of Sun Yat-sen University (38000-31131103), the Fundamental Research Funds for the Central Universities (19lgzd29) and the China Postdoctoral Science Foundation (2017M622869).

Abstract: The development of well-defined TiO2 nanoarchitectures is a versatile strategy to achieve high-efficiency photocatalytic performance. In this study, mesoporous TiO2 nanofibers consisting of oriented nanocrystals were fabricated by a facile vapothermal-assisted topochemical transformation of preformed H-titanate nanobelts. The vapothermal temperature is crucial in tuning the microstructures and photocatalytic redox properties of the resulting mesoporous TiO2 nanofibers. The microstructures were characterized with XRD, TEM, XPS and nitrogen adsorption-desorption isotherms, etc. The photocatalytic activities were evaluated by photocatalytic oxidation of organic pollutant (Rhodamine B as an example) as well as photocatalytic reduction of water to generate hydrogen (H2). The nanofibers vapothermally treated at 150℃ showed the highest photocatalytic activity in both oxidation and reduction reactions, 2 times higher than that of P25. The oriented alignment and suitable mesoporosity in the resulting nanofiber architecture were crucial for enhancing photocatalytic performances. The oriented alignment of anisotropic anatase nanocrystals shall facilitate faster vectorial charge transportation along the nanofibers architecture. And, the suitable mesoporosity and high surface area would also effectively enhance the mass exchange during photocatalytic reactions. We also demonstrate that efficient energy-recovering photocatalytic water treatments could be accomplished by a cascading oxic-anoxic process where the dye is degraded in the oxic phase and hydrogen is generated in the successive anoxic phase. This study showcases a novel and facile method to fabricate mesoporous TiO2 nanofibers with high photocatalytic activity for both clean energy production and environmental purification.

Key words: TiO2 nanofiber, Photocatalysis, Pollutant degradation, Hydrogen production