提高二氧化钛孔道中水分子扩散性的分子模拟  

Improving diffusion of water molecules in slits of titanium dioxide:molecular dynamics simulation

作　　者：魏明杰[1] 吕玲红[1] 朱育丹[1] 郭晓静[1] 陆小华[1] 

机构地区：[1]南京工业大学材料化学工程国家重点实验室,江苏南京210009

出　　处：《化工学报》2013年第1期365-373,共9页CIESC Journal

基　　金：国家自然科学基金重点项目(21136004);国家自然科学基金项目(21176113;20876073;21176112);中国博士后科学基金项目(20110491407)~~

摘　　要：众所周知,二氧化钛(TiO2)材料在光催化材料、生物材料、电化学和工业催化等多个领域表现出优异的性能,因而其在解决能源和环境危机中被寄予厚望。在上述TiO2材料的众多应用中往往都离不开水分子与TiO2材料的接触。TiO2表面结构,特别是水分子在TiO2表面上形成的微结构往往对于TiO2材料的应用起到关键作用。另一方面,大比表面积的TiO2材料表现出性能上的优势,因此制备具有纳米孔道结构的TiO2材料成为研究趋势。结合上述两点,水分子受限于TiO2纳米孔道中的行为成为研究的热点之一。以往的研究结果表明,水分子在TiO2表面具有强吸附作用,而该作用会影响到水分子在TiO2孔道中的流动性。本文意在通过分子模拟的研究,找到提高水分子TiO2孔道中扩散性的方法,并解释流动性增加的原因,为实验研究工作者们提供指导和解释。通过调整多项模拟参数,结果表明对于实验工作更为可靠的方法是用碳层覆盖TiO2的表面。这样可以在不改变原有实验条件的基础上大大提高水分子在TiO2孔道中的扩散性。Titanium dioxide（TiO2）materials are expected to play an important role in helping to solve many serious environmental and pollution challenges,because of their excellent performance in the fields of photocatalysis,biomaterials,electrochemistry and industrial catalysis.Among all the applications of TiO2 materials,there is a common process which is the contact of water molecules with TiO2 materials.Thus,the surface structure of TiO2,especially micro-structure of water molecules on TiO2 surface,plays a key role in the applications.Moreover,since the TiO2 material with larger surface area performs better,preparation of TiO2 materials with nanoporous structures has become a research direction.Hence,the behavior of water molecules confined in the nanopores of TiO2 is one of hot topics.Literature and our previous research showed that water molecules strongly adsorbed on the TiO2 surface,and the strong adsorption hindered the mobility of water molecules in the TiO2 pores.In this work we intended to improve the mobility of water molecules confined in TiO2pores by molecular dynamics studies,and to explain the reasons for the increase of mobility.These results could help experimental researchers to understand and reschedule their experiments.By adjusting a number of simulation parameters,we proposed that the more reliable method was covering the surface of TiO2 with a carbon layer.This method could greatly improve the mobility of water molecules in the TiO2pores without altering the original experimental condition.

关 键 词：二氧化钛 分子模拟 扩散 界面 水分子 碳 覆盖 

分 类 号：TQ015.9[化学工程]