FTIR and NMR study of the adsorbed water on nanocrystalline anatase
FTIR and NMR study of the adsorbed water on nanocrystalline anatase
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DOI：
10.1021/jp071440g
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发表时间：
2007-06
影响因子：
3.7
通讯作者：
J. Soria;J. Sanz;I. Sobrados;Juan M. Coronado;A. Maira;M. D. Hernández-Alonso;F. Fresno
中科院分区：
文献类型：
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作者：
J. Soria;J. Sanz;I. Sobrados;Juan M. Coronado;A. Maira;M. D. Hernández-Alonso;F. Fresno
采用煅烧法制备了一种晶体尺寸为11 nm的水合锐钛矿样品，通过FTIR、1H MAS NMR和TPD技术对其表面吸附的羟基和水的特征进行了研究。升高温度下水化和抽真空后样品的1H NMR和FTIR光谱表明，大部分水化锐钛矿水具有弱吸附和高流动性，形成多层水分子排列（MAs）。这种水在室温下容易解吸，有利于观察流动性较低的吸附水，其去除产生两个重叠的水解吸峰，在TPD剖面中观察到的最大值在353和373 K。大部分较弱吸附的水从MAs第二层解吸，产生低温最大值。另一方面，一些与桥接氧阴离子结合的水的去除，与末端羟基相互作用，有助于在373 K时达到最大。TPD峰值以…
A hydrated anatase sample with crystal size of 11 nm, prepared by a method involving a calcination treatment, has been studied by FTIR, 1H MAS NMR, and TPD techniques, to determine the characteristics of the hydroxyls and water adsorbed on its surface. The 1H NMR and FTIR spectra of the sample, hydrated and evacuated at increasing temperature, show that most of the hydrated anatase water, weakly adsorbed and highly mobile, is forming the multilayer of water molecular arrangements (MAs). The easy desorption of this water at room-temperature facilitates the observation of less mobile adsorbed water, whose removal originates two overlapped water desorption peaks, with maxima at 353 and 373 K, observed in the TPD profile. Most of this less weakly adsorbed water is desorbed from the MAs second layer, originating the low-temperature maximum. On the other hand, the removal of some water bound to bridging O2- anions, interacting with terminal hydroxyls, contributes to the maximum at 373 K. The TPD peak with maxim...