【作者】 李玉红； 吴新平； 蒋宁新； 林明； 高飞； 董林； 龚学庆； 彭路明；

【Author】 Yuhong Li;Xin-Ping Wu;Ningxin Jiang;Ming Lin;Fei Gao;Lin Dong;Xue-Qing Gong;Luming Peng;School of Chemistry and Chemical Engineering,Nanjing University;Centre for Computational Chemistry and Research Institute of Industrial Catalysis,East China University of Science and Technology;Institute of Materials Research & Engineering,A*STAR (Agency for Science,Technology and Research),3 Research Link;

【机构】 南京大学化学化工学院介观化学教育部重点实验室； 华东理工大学工业催化研究所计算化学中心； Institute of Materials Research & Engineering,A*STAR (Agency for Science,Technology and Research),3 Research Link；

【摘要】 借助¹⁷O水选择性地对主要暴露{101}和{001}的两种氧化钛纳米结构进行表面选择标记,测得的¹⁷O NMR信号均来自纳米晶表面,实验结果显示不同的晶面其¹⁷O NMR谱图显著不同。结合理论计算可以将这些信号与暴露晶面的结构关联起来,这是首次从实验上证实NMR可以用来区分纳米晶暴露的晶面。NMR结果能给出两种晶面的活性信息。在{001}晶面上,吸附很少的水时,表面即会发生重构;而在{101}晶面上,"台阶"（step edge）表面缺陷位表现出很强的O交换活性。因此,这一新表征方法将能对理解材料催化机理提供新机会。更多还原

【Abstract】 We develop a convenient ¹⁷O NMR strategy based on selective surface isotopic labelling to distinguish oxide nanocrystals exposing different facets.In combination with DFT calculations,we show that the oxygen ions on the {001} and {101} facets of anatase titania nanocrystals are associated with distinct ¹⁷O chemical shifts and these facets exhibit different reactivities.Surface reconstruction occurs on {001} facets when a small fraction of surface is adsorbed with water while step-edge defects show high activity in O exchange on the {101} facets.The results open up methods for characterizing faceted nanocrystalline oxides and related materials.更多还原