SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2019, Vol. 27 ›› Issue (11): 2825-2834.DOI: 10.1016/j.cjche.2019.04.002

• Materials and Product Engineering • Previous Articles     Next Articles

Engineering an ultrathin amorphous TiO2 layer for boosting the weatherability of TiO2 pigment with high lightening power

Yangyang Yu1, Kejing Wu2, Shiyu Lu3, Kui Ma1, Shan Zhong1, Hegui Zhang1, Yingming Zhu2, Jing Guo4, Hairong Yue1,2, Changjun Liu1,2, Siyang Tang1, Bin Liang1,2   

  1. 1 Low-Carbon Technology and Chemical Reaction Engineering Laboratory, School of Chemical Engineering, Sichuan University, Chengdu 610065, China;
    2 Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu 610207, China;
    3 Institute for Clean Energy & Advanced Materials, Faculty of Materials and Energy, Southwest University, Chongqing 400715, China;
    4 Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering, North University of China, Taiyuan 030051, China
  • Received:2018-11-12 Revised:2019-03-25 Online:2020-01-19 Published:2019-11-28
  • Contact: Bin Liang
  • Supported by:
    Supported by the National Key R&D Program of China (2018YFB0605700).

Engineering an ultrathin amorphous TiO2 layer for boosting the weatherability of TiO2 pigment with high lightening power

Yangyang Yu1, Kejing Wu2, Shiyu Lu3, Kui Ma1, Shan Zhong1, Hegui Zhang1, Yingming Zhu2, Jing Guo4, Hairong Yue1,2, Changjun Liu1,2, Siyang Tang1, Bin Liang1,2   

  1. 1 Low-Carbon Technology and Chemical Reaction Engineering Laboratory, School of Chemical Engineering, Sichuan University, Chengdu 610065, China;
    2 Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu 610207, China;
    3 Institute for Clean Energy & Advanced Materials, Faculty of Materials and Energy, Southwest University, Chongqing 400715, China;
    4 Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering, North University of China, Taiyuan 030051, China
  • 通讯作者: Bin Liang
  • 基金资助:
    Supported by the National Key R&D Program of China (2018YFB0605700).

Abstract: TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and therefore reduce the lightening power of TiO2. In the present work, a uniform, amorphous, 2.9-nm-thick TiO2 protective layer was deposited onto the surface of anatase TiO2 pigments according to pulsed chemical vapor deposition at room temperature, with TiCl4 as titanium precursor. Amorphous TiO2 coating layers exhibited poor photocatalytic activity, leading to a boosted weatherability. Similarly, this coating method is also effective for TiO2 coating with amorphous SiO2 and SnO2 layers. However, the lightening power of amorphous TiO2 layer is higher than those of amorphous SiO2 and SnO2 layers. According to the measurements of photoluminescence lifetime, surface photocurrent density, charge-transfer resistance, and electron spin resonance spectroscopy, it is revealed that the amorphous layer can prevent the migration of photogenerated electrons and holes onto the surface, decreasing the densities of surface electron and hole, and thereby suppress the photocatalytic activity.

Key words: TiO2 pigments, Pulsed chemical vapor deposition, Ultrathin layer, Weatherability, Lightening power, Photocatalytic suppression mechanism

摘要: TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and therefore reduce the lightening power of TiO2. In the present work, a uniform, amorphous, 2.9-nm-thick TiO2 protective layer was deposited onto the surface of anatase TiO2 pigments according to pulsed chemical vapor deposition at room temperature, with TiCl4 as titanium precursor. Amorphous TiO2 coating layers exhibited poor photocatalytic activity, leading to a boosted weatherability. Similarly, this coating method is also effective for TiO2 coating with amorphous SiO2 and SnO2 layers. However, the lightening power of amorphous TiO2 layer is higher than those of amorphous SiO2 and SnO2 layers. According to the measurements of photoluminescence lifetime, surface photocurrent density, charge-transfer resistance, and electron spin resonance spectroscopy, it is revealed that the amorphous layer can prevent the migration of photogenerated electrons and holes onto the surface, decreasing the densities of surface electron and hole, and thereby suppress the photocatalytic activity.

关键词: TiO2 pigments, Pulsed chemical vapor deposition, Ultrathin layer, Weatherability, Lightening power, Photocatalytic suppression mechanism