This work, using the first-principles theory, uses the Ni-decorated WSe2 (Ni-WSe2) monolayer as a novel gas sensing material upon CO and HCHO in the dry-type transformers in order to evaluate their operation status. Results indicate that the Ni atom can be stably adsorbed on the TW site of the pristine WSe2 monolayer with the binding force of -4.33 eV. Via the gas adsorption analysis, it is found that the Ni-WSe2 monolayer performs chemisorption upon CO and HCHO molecules, with adsorption energies of -2.27 and -1.37 eV, respectively. The analyses of the band structure and Frontier molecular orbital manifest the potential of the Ni-WSe2 monolayer as a resistance-type gas sensor upon CO and HCHO, with sensing responses of 55.9 and 30.9% based on the band gap change and of 55.0 and 38.5% based on the energy gap change. The analysis of the density of state clearly shows the modified electronic property of the Ni-WSe2 monolayer in gas adsorptions. On the other hand, the analysis of the work function (WF) reveals the limited possibility to explore the Ni-WSe2 monolayer as a WF-based gas sensor for CO and HCHO detections. This work systemically studies the sensing potential of the Ni-WSe2 monolayer upon two typical gas species in the dry-type transformers, which is meaningful to explore novel nanomaterial-based gas sensors to monitor the operation condition of electrical equipment.
© 2023 The Authors. Published by American Chemical Society.