Adsorption Behavior of Ni-Doped ZnO Monolayer upon SF6 Decomposed Components and Effect of the Applied Electric Field

In this article, Ni-doped ZnO (Ni-ZnO) monolayer is proposed as a potential sensing material for detection of two SF 6 decomposed components (namely, SO 2 and SOF 2 ), based on the density functional theory (DFT) method, to monitor the operation status of SF 6 insulation devices in the power system. The Ni-doping effect on the physicochemical properties of the pure ZnO monolayer is first studied, with the binding energy ( E b ) calculated as -1.49 eV. Then, the adsorption of a Ni-ZnO monolayer upon SO 2 and SOF 2 molecules shows that the Ni-ZnO monolayer exhibits strong chemisorption upon the two gas species, with the adsorption energy ( E ad ) obtained as -2.38 and -2.19 eV, respectively. The electronic properties of the Ni-ZnO monolayer upon gas adsorption are studied through the density-of-state (DOS) analysis, whereas the band structure (BS) and work function (WF) analysis provide the sensing mechanism of the Ni-ZnO monolayer upon two gases. In addition, the charge-transfer behavior during adsorption in the applied electric fields is analyzed to expound the possibility of Ni-ZnO monolayer as a field-effect-transistor gas sensor. Our calculations can stimulate the study on adsorption and sensing behaviors of TM-ZnO monolayers for their applications in many fields.