Study on the Adsorption Characteristics of Mo-Doped Graphene on the Decomposition Products of SF6 Substitute Gas Based on First-Principle Calculations

Abstract

C4F7N, C5F10O, etc., as new environmental-friendly alternative gases decompose under partial discharge and produce a series of products such as CO, CF4, C2F6, C3F8, CF3CN, C2F5CN, and COF2. Based on the first-principles calculation method of density functional theory (DFT), the adsorption characteristics of intrinsic state graphene and Mo-doped graphene adsorbing SF6 and its substitute gas decomposition products are calculated and analyzed. By comparing the adsorption energy, adsorption distance, density of state, Mulliken charge population, charge transfer amount, and molecular orbital energy for adsorbing different decomposition gases, it can be seen that the system structure is the most stable when Mo is doped at the T site of the graphene surface. The adsorption of Mo-doped graphene on gas molecules is significantly stronger than that of intrinsic graphene, and the order of adsorption is: SO2F2 > H2S > SO2 > CF4. The adsorption of H2S gas molecules by intrinsic state and Mo-doped graphene is n-type adsorption, while the adsorption of SO2F2, CF4, and SO2 gas molecules is p-type adsorption. Mo-doped graphene can be used as a detection device for SO2F2 gas resistance sensors.

Advances in 2D Materials Based Gas Sensors for Industrial Machine Olfactory Applications

“…Regardless of computing platform and configurations, most established sensing substrates with metal or metal oxide dopants displayed large E ads and Q t upon SOF 2 and SO 2 F 2 molecules, which usually experience chemical bond fracture during adsorption (Figure a). Although higher E ads and Q t possibly indicate a better response property, it increases the difficulty of sensor recovery. − According to the theoretical desorption formula, τ = v 0 –1 exp­(− E ads /( kT )), where τ is the desorption time, v 0 is the attempt frequency, − k is the Boltzmann constant, and T is the temperature, the desorption time increases exponentially with the increase of E ads at a fixed temperature. Therefore, blindly pursuing high E ads and Q t will expose the sensors to the risk of poisoning and short lifespan.…”

Detection of SF₆ Decomposition Gases by the Pristine and Fe-Doped Porphyrin Based on the First-Principles Calculations

“…The potential of two-dimensional (2D) materials as adsorbent materials for environmental protection is significant due to their high surface area, controlled interlayer bonding, specific binding capacity, chemical stability and sensitivity [13,14]. In recent years, a variety of 2D materials, including 2D sulfur compounds [2,15], ZnO [16], C3N [17], MXenes [18], graphene [19] and the group III-V nitrides [20] have demonstrated high efficacy in the detecting and capturing harmful gases. For instance, Hu et al [21] investigated the adsorption characteristics of NH3, CO and NO2 on SnS monolayers, and the results showed that there exists a significant adsorption effect of NO2 on the SnS monolayers.…”