以钛酸正丁酯和SnCl4·5H2O为前驱体,采用溶胶-凝胶法制备了SnO2及Sn/Ti摩尔比为5/1的SnO2-TiO2复合纳米材料,并以此复合材料制备了旁热式气敏传感器,对两者的氢敏性能做了比较,利用第一性原理对其气敏机理进行了理论分析.结果表明,TiO2的掺杂使SnO2导带底部产生了掺杂能级,使SnO2元件电阻下降,并随温度的上升出现先快速下降后缓慢下降2个过程.SnO2-TiO2元件对H2的灵敏性明显优于SnO2元件.吸附H后的SnO2电子态密度变化较小,而SnO2-TiO2的电子态密度则有明显变化,并产生了掺杂能级,导带负移,促进了能带间的电子转移.
SnO2 and SnO2-TiO2 nanosized composite materials had been prepared with Ti(OC4 H9)4 and SnCl4·5 H2 O as precursors by sol-gel method, and the indirect heating gas sensors were prepared using these materials. Gas-sensing properties of the materials for Hydrogen was studied,and gas-sensing mechanism was analyzed by the first principle. The results showed that the doped energy-band is generated at the base of conduction band of SnO2 with doping TiO2. The resistance of SnO2 sensors declines rapidly first and then declines slowly with tem-perature rising. Sensitivity of SnO2-TiO2 sensors for hydrogen is better than the SnO2 sensors evidently. There is a little changes in density of electronic states (DOS) of SnO2 after adsorbing H atom,while the DOS of SnO2-TiO2 has changed distinctly. Through doping TiO2 to SnO2, some doping energy bands appear and the conduct-ance bands move towards low energy, which are beneficial to the electron transfer between the energy bands.
参考文献
| [1] | Taurino A M;Capone S;Siciliano P et al.[J].Sensors and Actuators B:Chemical,2003,92:292-302. |
| [2] | Zhu B L;Xie C S;Wang W Y et al.[J].Materials Letters,2004,58:624-629. |
| [3] | 曾文;林志东.[J].传感器世界,2007:9-13-16. |
| [4] | 张怡,施利毅,张仲燕.纳米SnO2/TiO2复合光催化材料的制备[J].上海大学学报(自然科学版),2000(04):333-337. |
| [5] | 颜秀茹,李晓红,霍明亮,郭伟巍,巩永进.纳米SnO2@TiO2的制备及其光催化性能颜秀茹李晓红霍明亮郭伟巍巩永进[J].物理化学学报,2001(01):23-27. |
| [6] | 路金林,方庆红,伞晓广,李旭日.纳米TiO2/SnO2粉体的溶胶-凝胶法制备研究[J].有色矿冶,2004(02):37-38,42. |
| [7] | 徐自力,薛宝永,杨秋景,谢超,张剑宝,杜尧国.纳米TiO2-SnO2的制备及其对庚烷的气相光催化性能[J].应用化学,2004(10):980-984. |
| [8] | 曾文,林志东,高俊杰.金属离子掺杂纳米SnO2材料的气敏性能及掺杂机理[J].纳米技术与精密工程,2008(03):174-179. |
| [9] | 樊亮,彭同江,段涛.纳米SnO2粉体的制备与掺杂研究[J].电子元件与材料,2005(11):1-4. |
| [10] | 汪成建,徐明霞,施加婉君,鄂磊,徐永韬.SnO2的复合方式对TiO2晶型转变的影响[J].应用化学,2003(11):1096-1098. |
| [11] | Ding X Z;Liu X H;He Y Z .[J].Journal of Materials Science Letters,1996,15(20):1789-1791. |
| [12] | Marlo M;Milman V .[J].Physical Review B:Condensed Matter,1990,41:7892-7895. |
| [13] | Kohn W;Sham L J .[J].Physical Review A,1965,140(04):1133-1138. |
| [14] | Kresse G;Furthmuller J .[J].Computational Materials Science,1996,6:15-50. |
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