Anhydrous Silicophosphoric Acid Glass: Thermal Properties and Proton Conductivity
Anhydrous Silicophosphoric Acid Glass: Thermal Properties and Proton Conductivity
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无水硅磷酸玻璃：热性能和质子传导率
DOI：
10.1002/cphc.202100840
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发表时间：
2021
期刊：
影响因子：
2.9
通讯作者：
Nishii Junji
中科院分区：
文献类型：
--
作者：
Omata Takahisa;Sharma Aman;Suzuki Issei;Ishiyama Tomohiro;Kohara Shinji;Ohara Koji;Ono Madoka;Ren Yang;Zagarzusem Khurelbaatar;Fujioka Masaya;Zhao Gaoyang;Nishii Junji
合成了组成为H5 Si 2 P9 O29的无水硅磷酸玻璃，并对其热性能和质子传导性能进行了表征。尽管在192 °C下表现出玻璃化转变，但由于其高粘度，过冷液体可以在高达280 °C下作为固体处理。玻璃及其熔体表现出质子传导，质子传输数为1.01。虽然共价O−H键被相对较强的氢键削弱，但质子传导率（276 °C时为4×10−4S cm− 1）远低于磷酸。熔体的高粘度是由于磷酸根离子链通过六重配位的Si原子的紧密交联。低质子传导率归因于带正电荷的质子载体被捕获在阴离子SiO 6单元（表示为（SiO 6/2）2−）周围以补偿负电荷。
Anhydrous silicophosphoric acid glass with an approximate composition of H5Si2P9O29was synthesized and its thermal and proton‐conducting properties were characterized. Despite exhibiting a glass transition at 192 °C, the supercooled liquid could be handled as a solid up to 280 °C owing to its high viscosity. The glass and its melt exhibited proton conduction with a proton transport number of ∼1. Although covalent O−H bonds were weakened by relatively strong hydrogen bonding, the proton conductivity (4×10−4S cm−1at 276 °C) was considerably lower than that of phosphoric acid. The high viscosity of the melt was due to the tight cross‐linking of phosphate ion chains by six‐fold‐coordinated Si atoms. The low proton conductivity was attributed to the trapping of positively charged proton carriers around anionic SiO6units (expressed as (SiO6/2)2−) to compensate for the negative charges.