基于第一性原理计算Mn掺杂MoS_(2)对油中溶解气体的吸附性能

Calculation based on the first-principle on the adsorption performance of Mn doped MoS_(2)for dissolved gases in oil

CO、C_(2)H_(2)、CH_(4)是溶解在变压器油中的典型故障特征气体,其种类和浓度能够反映油浸式变压器绝缘故障的不同类型和严重程度,进行油中溶解气体分析是在线检测变压器运行状态的重要方法.基于第一性原理,通过Mn-MoS_(2)单层对三种气体的吸附能、转移电荷、态密度和形变电荷密度等参数以及解吸性能分析和灵敏度计算,提出了一种基于Mn-MoS_(2)材料的气敏传感器对油中溶解气体进行分析的方法.结果表明Mn-MoS_(2)对CH_(4)是物理吸附,对CO和C_(2)H_(2)是化学吸附.对于Mn-MoS_(2)来说,CH_(4)在常温下吸附能力差且灵敏度低,CO在不同温度下均有较强的吸附能力,而C_(2)H_(2)在常温下吸附稳定,高温下易解吸且响应灵敏度高.因此,Mn掺杂的MoS_(2)体系可预期作为CO的气体吸附剂和检测C_(2)H_(2)的新型电阻型气敏传感器.

CO,C_(2)H_(2) and CH_(4) are typical fault characteristic gases dissolved in transformer oil.Their types and concentrations can reflect different types and severity of insulation faults.Dissolved gas analysis in oil is an effective method for on-line detection of transformer operation state.Therefore,a gas sensor based on Mn-MoS_(2) is proposed to analyze gas in oil.The adsorptions of three gases on Mn-MoS_(2) monolayer were studied based on the first principle.The parameters such as adsorption energy,transfer charge and deformation charge density were analyzed.At the same time,desorption performance analysis and sensitivity calculation were also carried out.The results show that Mn-MoS_(2) is chemisorption for CO and C_(2)H_(2) and physical adsorption for CH_(4).The desorption performance of CO on Mn doped MoS_(2) is poor,the adsorption of C_(2)H_(2) is stable at room temperature,easy to desorb at high temperature and high sensitivity,CH_(4) is easily desorbed at room temperature.Therefore,Mn doped MoS_(2) can be expected as a gas adsorbent for CO and a new resistive gas sensor for detecting C_(2)H_(2).