基于DFT的氮参杂TiO₂ (101)检测H2S的气敏特性研究

Study on Gas Sensing Characteristics of Nitrogen Doped TiO₂ (101) for Detecting H2S Based on DFT

SF6绝缘气体作为电力系统中最重要的气体绝缘介质之一,具有灭弧能力强、无毒等突出优点。但其在设备内部绝缘缺陷产生的局部放电作用下,会分解生成包括SO2F2,SO2和H2S在内的几种特征物质,降低SF6气体绝缘性能。而通过化学气体传感器检测SF6特征分解组分,实现气体绝缘设备故障诊断与在线监测技术,已被认为是估算电气工程中绝缘设备运行状态的可行方法。研究发现TiO2纳米管传感器对SF6分解组分H2S具有良好的响应,因此TiO2纳米管传感器具有增强的敏感性和对气体分子的响应。本文基于密度泛函理论方法模拟了SF6分解组分H2S在N掺杂TiO2上的吸附特性。结果表明,N-TiO2对H2S的敏感性较好,吸附后电导率发生明显变化。

As one of the most important gas insulation media in power system, SF6 insulating gas has the outstanding advantages of strong arc extinguishing ability and non-toxic. Under the action of partial discharge caused by the internal insulation defects of the equipment, several characteristic substances, including SO2F2, SO2 and H2S, will be decomposed and generated, which will reduce the insulation performance of SF6 gas. By detecting SF6 characteristic decomposition components by chemical gas sensor, fault diagnosis and on-line monitoring technology of gas insulation equipment has been considered as a feasible method to estimate the running state of insulation equipment in electrical engineering. The study found that N-TiO2 sensor has a good response to the H2S of SF6 decomposition components, so N-TiO2 sensor has enhanced sensitivity and response to gas molecules. The adsorption characteristics of SF6 decomposition component H2S on N doping TiO2 are simulated based on density functional theory method. The results show that the sensitivity of the N-TiO2 to the H2S is good, and the conductivity changes obviously after adsorption.