title: Simple ethanol impregnation treatment can enhance photocatalytic activity of TiO2 nanoparticles under visible-light irradiation.
abstract: Doping with impurities as well as introducing oxygen vacancies has been recognized as an important means to enhance photocatalytic activity of TiO2 under visible-light irradiation. Here we report that simple ethanol impregnation followed with mild heat treatment (150-400 °C) can color TiO2 nanoparticles and enhance visible-light photocatalytic activity of the material. The coloration and photocatalytic activity for β-naphthol and rhodamine B (RhB) degradation were observed to be dependent on heat-treatment temperature, and the highest activity as well as the most coloration was obtained at temperatures around 200 to 250 °C. Comprehensive analyses based on X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) investigations as well as first-principle density functional calculation suggest that the simple ethanol impregnation treatment leads to the generation of oxygen vacancy on TiO2 surface which should be responsible for the coloration and enhanced photocatalytic activity.
authors: †Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China.
authors: Lina
authors: L
authors: Kong
authors: ‡School of Physics, Chongqing University, Shapingba, Chongqing 401331, China.
authors: Zhiqiang
authors: Z
authors: Jiang
authors: †Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China.
authors: Changhua
authors: C
authors: Wang
authors: †Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China.
authors: Fangxu
authors: F
authors: Wan
authors: †Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China.
authors: Yingying
authors: Y
authors: Li
authors: §Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
authors: Liangzhuan
authors: L
authors: Wu
authors: §Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, 29 Zhongguancun East Road, Haidian District, Beijing 100190, China.
authors: Jin-Fang
authors: JF
authors: Zhi
authors: †Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China.
authors: Xintong
authors: X
authors: Zhang
authors: ‡School of Physics, Chongqing University, Shapingba, Chongqing 401331, China.
authors: Shijian
authors: S
authors: Chen
authors: †Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China.
authors: Yichun
authors: Y
authors: Liu
keywords: TiO2; density functional calculation; ethanol impregnation; oxygen vacancy; visible-light photocatalyst