纳米TiO2光催化还原Hg2+的分子动力学模拟

摘要

采用分子动力学方法模拟了Hg2+在TiO2表面上光催化还原反应中的运动过程,结果表明,在TiO2表面的水分子会形成局部有序的类冰结构,这种类冰结构限制了材料表面附近水分子的移动,也阻碍了Hg2+向TiO2表面的运动,是影响光催化效率的一个重要因素.同时,还模拟了TiO2表面光生电子密度和表面掺杂Fe3+对类冰结构的影响,结果表明,TiO2表面掺杂Fe3+抑制了类冰结构的形成,有利于提高光催化效率.%The movement process of Hg2+ on the surface of TiO2 in photocataytic reduction reactions was simulated through molecular dynamics simulation method It was found that the water molecules can form a kind of partially ordered ice-like structure on the surface of TiO2. This kind of ice-like structure, being a vital influence factor of the photocatalysis efficiency, hinders the movement of water molecule on the surface of the materials and prevents Hgz+ from moving towards the surface of TiQ2. The influence exerted on the ice-like structure by the density of pho- . Togenerated electrons on the TiO2 surface and doping Fe3+ on the surface was also simulated. The result showed that doping Fe3+ on the surface of TiO2 restrains the formation of the ice structure, and thus improves the photocatalysis efficiency.