Ti(3)C(2)T(x) as a Sensor for SF(6)/N(2) Nitrogen-Containing Fault Decomposition Characteristic Products: A Theoretical Study

The SF(6)/N(2) gas mixture is an alternative gas to SF(6). SF(6)/N(2) will decompose and generate nitrogenous characteristic gases, such as NO, NO(2), N(2)O, and NF(3), when exposed to long-term partial discharge. The adsorption models of Ti(3)C(2)T(x) (T=O, F, OH) and NO, NO(2), N(2)O, NF(3) were constructed, and the most stable adsorption structure was selected in this paper. The electron density and density of states of the adsorption system were further analyzed to study the adsorption behavior, and the sensing performance was evaluated in the end. The results are as follows: four gases could be spontaneously adsorbed on Ti(3)C(2)T(x), and strong adsorption occurred when surface terminal groups were OH, forming hydrogen or chemical bonds with significant charge transfer. Results show that Ti(3)C(2)(OH)(2) had a stronger sensing ability than Ti(3)C(2)F(2) and Ti(3)C(2)O(2). The conductivity of the Ti(3)C(2)T(x) with different terminal groups was improved after the adsorption of NO and NO(2), showing Ti(3)C(2)T(x) had a good sensing ability for NO and NO(2). It was difficult for the four gases to desorb from the Ti(3)C(2)(OH)(2) surface, but the adsorption on the Ti(3)C(2)F(2), Ti(3)C(2)O(2) surface had a short recovery time at room temperature.