Seredych Mykola, Bandosz Teresa J
Department of Chemistry, The City College of New York, 160 Convent Avenue, New York, NY 10031, USA.
J Colloid Interface Sci. 2008 Aug;324(1-2):25-35. doi: 10.1016/j.jcis.2008.04.062. Epub 2008 May 1.
Graphite oxide (GO) synthesized from commercial graphite was modified with aluminium or zirconium-aluminium polyoxycations and then calcined at 350 degrees C. On the samples obtained adsorption of ammonia from moist air was investigated. The surface of materials before and after exposure to ammonia was characterized using adsorption of nitrogen, XRD, SEM, FTIR, TA, CHN analysis, and potentiometric titration. The results showed that in spite of the fact that graphite composites/pillared graphites (PG) have Keggin-like ions located between the layers, that space blocked for nitrogen molecules used to determine the specific surface area. During calcinations, the deflagration of layers occurred as a result of decomposition of epoxy groups. This results in formation of disordered graphitic carbons with some mesoporosity. Even though these materials were not porous, the significant amount of ammonia was retained on the surface. Since ammonia molecule is able to specifically interact with oxygen groups of graphite oxide and Brønsted centers of inorganic pillars, it is likely intercalated between the composite layers. While the best performance was found for GO modified with aluminium-zirconium species, after calcinations the samples containing Keggin Al(13) like cations revealed the high capacity which is linked to the high acidity of incorporated inorganic compounds.
由商业石墨合成的氧化石墨（GO）用铝或锆铝聚氧阳离子进行改性，然后在350℃下煅烧。对所得样品进行了从潮湿空气中吸附氨的研究。使用氮气吸附、XRD、SEM、FTIR、TA、CHN分析和电位滴定对暴露于氨前后的材料表面进行了表征。结果表明，尽管石墨复合材料/柱撑石墨（PG）在层间存在类Keggin离子，但该空间被用于测定比表面积的氮分子所占据。在煅烧过程中，环氧基团分解导致层间爆燃。这导致形成具有一些介孔率的无序石墨碳。尽管这些材料没有孔隙，但大量的氨保留在表面。由于氨分子能够与氧化石墨的氧基团和无机柱的布朗斯特中心发生特异性相互作用，它很可能插入复合层之间。虽然用铝锆物种改性的GO表现出最佳性能，但煅烧后含有类Keggin Al(13)阳离子的样品显示出高容量，这与掺入的无机化合物的高酸度有关。
