模拟太阳光下锗掺杂纳米TiO_2对化学毒剂的降解性能

Degradation of Chemical Warfare Agents by Germanium-doped Nanosized TiO_2 under Simulated Sunlight Irradiation

采用均匀沉淀法制备不同锗掺杂浓度的纳米二氧化钛(Ti O2);为了研究掺杂浓度与粉体活性之间的关系,针对化学毒剂(CWAs)模拟剂2-氯乙基乙基硫醚(2-CEES)和甲基膦酸二甲酯(DMMP)开展光催化消毒实验,并用动力学方程拟合实验结果;通过XRD、UV-Vis、BET、BJH、SEM和TEM等技术对样品进行表征,分析锗掺杂对Ti O2结构及性能的影响;综合考虑溶剂的毒性、挥发性、可燃性和溶解性等因素,以氢氟醚(HFE)作为分散溶剂,研究模拟太阳光下Ge-Ti O2和HFE混合体系对芥子气(HD)、梭曼(GD)和维埃克斯(VX)的消毒性能。结果表明:适量锗掺杂不会改变纳米Ti O2的晶型结构,可以减小晶粒尺寸,增大比表面积,增强光利用率,提高消毒活性;相较于直接使用粉体消毒,混合体系的消毒效率明显提高;在模拟太阳光下,最佳锗掺杂浓度(6.24wt%)样品与HFE-458(HCF2CF2CH2OCF2CF2H)组成的混合体系与三种化学毒剂反应60 min的降解率分别为:HD 98.73%、GD 100%、VX 100%。

Titanium dioxide（Ti O2） nanoparticles doped with varying amounts of germanium were prepared by homogeneous precipitation method. To investigate the relationship between doping content and photocatalytic activity, the photocatalytic degradation efficiency of 2-chloroethyl ethyl sulphide（2-CEES） and dimethyl methylphosphonate（DMMP） on the prepared samples were examined, and the data were fitted by a kinetic equation. After that, physical properties of the samples were determined by XRD, UV-Vis, BET, BJH, SEM, and TEM. For consideration of toxicity, volatility, flammability, and solubility, hydrofluoroether（HFE） was first used as dispersion solvent. Ge-Ti O2 was dispersed in HFE-458（HCF2CF2CH2OCF2CF2H）, and the disinfection efficiency of sulphur mustard（HD）, soman（GD） and S-2-（diisopropylamino）ethyl O-ethyl methylphosphonothiolate（VX） were studied under the simulated sunlight irradiation. These results show that Ge（6.24wt%）-Ti O2 exhibits the best photocatalytic performance. Appropriate amount of Ge dopant doesn＇t change the crystal structure of Ti O2, but reduces the grain size, increases the surface area, improves the light utilization, and improves the photocatalytic disinfection activity of Ti O2. After reacting with Ge（6.24wt%）-Ti O2 and HFE-458 suspension for 60 min, the degradation efficiency of HD, GD and VX is 98.73%, 100% and 100%, respectively.