光催化剂TiO_2改性的研究进展

Research progress on modification of TiO_2 photocatalyst

Ti O_2具有光催化性能好、化学性质稳定、毒性低、价格低廉等优点,但由于禁带较宽,只对紫外光有响应,且电子和空穴容易复合,导致光催化活性和效率降低。本文介绍了Ti O_2的几种主要改性方法的最新研究进展。表面沉积贵金属、半导体复合、染料敏化可以降低Ti O_2的禁带宽度,增加其响应波长,提高太阳光的利用率。离子掺杂可使得Ti O_2晶体表面产生缺陷,抑制光生电子和空穴的复合,增加表面活性中心的数量。碳纳米管和石墨烯掺杂则能够提高Ti O_2对可见光的吸收率,扩大光响应范围,同时加快电子传输,减少载流子复合,提高催化效率。指出石墨烯作为新型掺杂材料具有很大的发展潜力,Ti O_2基多组分复合型光催化剂可获得比单种组分表面改性或者掺杂Ti O_2更好的效果。最后介绍了Ti O_2表面的亲/疏水改性研究进展。

TiO2 has such advantages as excellent photocatalytic performance,high chemical stability, low toxicity and price. However,it only responds to UV light due to its wide forbidden band,and the electrons and holes are prone to recombination,leading to a decrease of catalytic activity and efficiency. This paper introduced the latest research progress on several main modification methods of TiO2. Surface deposition of noble metal,semiconductor composite and dye sensitization can reduce the width of the forbidden band,increase the response wavelength and make full use of the sunlight. Ion doping can make TiO2 crystal surface generate the defects,restrain the recombination of photoproduction electrons and holes,and increase the number of surface active centers. Carbon nanotube and graphene modification can improve light absorption of TiO2to the visible,extend the response range, speed up the electronic transmission,reduce the carrier recombination,and upgrade the catalytic efficiency. As a new doping material graphene has great potentials,and TiO2-based multi-components composite photocatalysts are promising to achieve better catalytic properties than single-component surface modified or doped TiO2. Finally,research progress on hydrophilic/hydrophobic surface modification of TiO2 was reviewed.