51. Proton conduction in and structure of P2O5-TiO2-CaO-Na2O sol-gel glasses
- Author
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Jae Young Shin, Dae Sung Kim, and Bong-Ki Ryu
- Subjects
Materials science ,Oxide ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Amorphous solid ,Phosphate glass ,Titanium oxide ,chemistry.chemical_compound ,Differential scanning calorimetry ,chemistry ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Titanium ,Sol-gel - Abstract
Phosphate sol-gel-derived glasses in a P2O5-CaO-Na2O-TiO2 system with a high TiO2 content of up to 50 mol% were synthesized. A sol-gel method was chosen because incorporating a high percentage of titanium into the phosphate network via traditional melt-quench methods is not trivial. The structural and the thermal properties of the obtained stabilized sol-gel glasses were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry. The XRD results confirmed the amorphous and glassy nature of the prepared samples. The FTIR results revealed that, with the addition of TiO2, titanium oxide (TiO6) (which likely acts as a modifier oxide) entered the network. Consequently, the number of terminal oxygen atoms increased, leading to an increase in the number of P-OH bonds. The proton conductivity of the sol-gel glass samples was as high as 0.0102 S·cm−1 at a relative humidity of 100% and a temperature of 100 ◦ C. The FTIR analysis confirmed the presence of (HPO4)2− - and (H2PO4)−-coordinated phosphorous. These functional groups acted as a bridge in the Grotthuss proton-conduction mechanism.
- Published
- 2017
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