Chinese Journal of Catalysis ›› 2015, Vol. 36 ›› Issue (11): 1943-1948.DOI: 10.1016/S1872-2067(15)60946-9

• Articles • Previous Articles     Next Articles

Black TiO2(B)/anatase bicrystalline TiO2-x nanofibers with enhanced photocatalytic performance

Licheng Lia, Kangzhong Shib, Rui Tub, Qi Qiana, Dong Lic, Zhuhong Yangb, Xiaohua Lub   

  1. a College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China;
    b State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009, Jiangsu, China;
    c Jiangsu Sunpower Technology Co. Ltd., Nanjing 211112, Jiangsu, China
  • Received:2015-04-24 Revised:2015-07-03 Online:2015-11-02 Published:2015-11-02
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21406118, 91434109, 91334202), the Highly Educated Talent Foundation of Nanjing Forestry University (GXL2014036), the Doctor Program of Jiangsu Province, Distinguished Experts Program of Science and Technology Vice-manager (Enterprise Innovation Job), and the Priority Academic Program Development of Jiangsu Higher Education Institutions.

Abstract:

Black TiO2(B)/anatase bicrystalline TiO2-x nanofibers were synthesized from a porous titanate derivative by calcination in H2, and were characterized using field-emission scanning electron microscopy, Raman spectroscopy, N2 adsorption-desorption analysis, X-ray photoelectron spectroscopy, thermogravimetric analysis, ultraviolet-visible diffuse reflection spectroscopy and photoluminescence measurements. Characterization results showed that no Ti3+ was present on the surface of black bicrystalline TiO2-x and oxygen vacancies were distributed in the bulk of both TiO2(B) and anatase phases. The O/Ti atom stoichiometric ratio of black bicrystalline TiO2-x was estimated to be 1.97 from the difference of mass loss between black bicrystalline TiO2-x and white bicrystalline TiO2 without oxygen vacancies. The photocatalytic activity of black bicrystalline TiO2-x was 4.2 times higher than that of white bicrystalline TiO2 and 10.5 times higher than that of anatase TiO2. The high photocatalytic activity of black bicrystalline TiO2-x was attributed to its effective separation of electrons and holes, which may be related to the effects of both bicrystalline structure and oxygen vacancies. Black bicrystalline TiO2-x also exhibited good photocatalytic activity after recycling ten times. The black bicrystalline TiO2-x nanofibers show potential for use in environmental and energy applications.

Key words: Black titania, Bicrystalline, Photocatalysis, Oxygen vacancy