Pompon-like WS ₂ nanostructure-based gas sensor was fabricated, and the sensing performance with micro mechanism to SF ₆ decompositions were discussed. At optimal working temperature, the sensor experiences resistance increasing for all four SF ₆ decompositions (SO ₂ , SOF ₂ , SO ₂ F ₂ , and H ₂ S). At low concentration (0~50 ppm), the sensor shows high linearity (R ² >0.99), and the rank of the sensitivity is: H ₂ S>SO ₂ >SO ₂ F ₂ >SOF ₂ . Furthermore, the first-principles results indicate that the different sensitivity is derived from the chemical interactions and electron transfer between the adsorbed molecule and the edge structures of WS ₂ . This work gives experimental and theoretical support of TMDCs based gas sensor to detect SF ₆ decompositions, and provides insights to design high-performance TMDCs based gas sensor from theoretical aspect.

Among the numerous novel eco-friendly insulating gases, C₄F₇N has attracted much attention due to its excellent electrical performance. However, except for the electrical perfomance, the compatibility between the gas medium and the sealing materials is equally important for gas-insulated equipment. At present, studies about the compatibility between C₄F₇N and EPDM, a widely used sealing material in power systems, are available in some previous works, but few focused on the compatibility comparison between C₄F₇N gas mixtures and EPDM with different third monomers. In this paper, we carried out the thermal aging test on ENB-EPDM, DCPD-EPDM, and C₄F₇N gas mixture to perfect the compatibility mechanism between EPDM and C₄F₇N. It was found that both of the EPDM reacted with the gas mixture and led to the property changes in the solid samples and the decomposition of C₄F₇N. On the other hand, by coating silicone grease, the contact between gas and rubber was effectively blocked and the concentration of the decomposition product was significantly reduced. The performance comparison indicates that ENB-EPDM is more suitable for sealing the C₄F₇N gas mixture, which is due to the superior thermal stability of ENB.

With the development of two-dimensional materials such as graphene, transition metal dichalcogenides (TMDs), MXenes and MBenes, these materials have received extensive attention from scholars in the field of gas sensing due to their unique and superior properties. Based on first-principles calculations, the adsorption energy, charge transfer, density of states and deformation charge density of CrB, an MBene successfully synthesized under laboratory conditions, were investigated for the adsorption of the decomposition components (CF₄, C₃F₆ and COF₂) of an insulating medium, C₄F₇N. The calculation results revealed strong chemisorption with an adsorption energy as high as −3.336 eV between CrB and COF₂, as well as physical adsorption with CF₄ and C₃F₆. However, the excessive interaction strength makes it difficult for COF₂ molecules to escape from the binding of the CrB substrate, making CrB more suitable as an adsorbent to remove COF₂ gas. Compared with COF₂ and CF₄, CrB has appropriate adsorption energy and charge transfer for C₃F₆ adsorption, and its theoretical recovery performance is acceptable, indicating its potential as a sensor for detecting C₃F₆.