Electronic Supplementary Information (ESI)
Bio-inspired design of a transparent TiO2/SiO2 composite gel coating with adjustable wettability †
Fuchao Yang ac and Zhiguang Guo *ab
a State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People’s Republic of China
b Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials and Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430062, People’s Republic of China
c University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
*The corresponding author: Tel: 0086-931-4968105; Fax: 0086-931-8277088; Email: .
Supplementary characterization section
The crystal structure of the as-prepared samples were characterized by X-ray diffraction (XRD) analysis using a X'SPERT PRO diffractometer with Cu Kα radiation of 1.5418 Å wavelength at 2θ ranging from 20° to 90°. The micro-morphology was also studied by light microscopy (ZEISS, Imager A2m). The measurement of Thermo-Gravimetric Analysis (TGA, Instrument type: STA 449F3, NETZSCH Corp., Ltd.) was conducted in air. Test range was 25 ˚C - 900 ˚C and heating rate was 10 ˚C·min−1. In the experiment of catalytic degradation, the 0.01g TiO2/SiO2 composite gel powder was dispersed into the Rhodamine B solution (10 μM, 50 mL). 10 mL samples were drawn from the Rhodamine B degradation systems after 2 h Uv irradiation. After high speed centrifugation (14000 r/min, 15 min), the relative concentration change of Rhodamine B solution was obtained by its maximum absorbance peak (553.7 nm). Control experiment with using the same amount of commercial SiO2 powder under Uv irradiation was also conducted.
Supplementary Figures
Fig.S1 XRD patterns of the precursor of TiO2/SiO2 sample before (1) and after (2) hydrothermal reaction
The XRD patterns indicate that the TiO2/SiO2 was not crystallographic, exhibiting amorphous state even after hydrothermal reaction. This was consistent with its gel form.
Fig.S2 Light microscopy view of TiO2/SiO2 composite gel deposited on silicon substrate
Fig.S3 AFM and its corresponding analyses of TiO2/SiO2 composite gel deposited on glass substrate
Fig.S4 The visualized electric phenomenon of TiO2/SiO2 composite coatings on ITO substrate
Fig.S5 (a) The thermal analysis of superhydrophobic TiO2/SiO2 hybrid gel. The XPS full spectrum (b) and Ti 2p fine spectrum (c) of TiO2/SiO2 hybrid gel after heat treatment (450 ºC and 2 h).
Fig.S6 The measurement of oil droplet CA (1,2-dichloroethane) underwater.
Fig.S7 The photoinduced catalytic activity of superhydrophilic TiO2/SiO2 composite gel to degrade Rhodamine B.
The original Rh B solution, control Rh B solution and TiO2/SiO2 photoinduced catalytic Rh B solution were denoted as S1, S2 and S3. After 2 h Uv-irradiation, the concentration of control Rh B solution sample rise and this was attribute to the evaporation of solvent: water. The 250 W light source radiate in a sealed space and the significant increase of ambient temperature facilitate its evaporation. This phenomenon was also confirmed by our other experiments. It shows undoubtedly that the maximum absorption peak at 553.7 nm decreased much, even consideration of thermal evaporation. In addition, the maximum absorption peak was blue shifted which is usually ascribed to the formation of intermediate products after a series of de-ethyl reaction. Both of these two evidences can well demonstrate that its photoinduced catalytic activity can be reserved after TiO2/SiO2 composite gel being heat treated at 450 °C for 2h.
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