Ni-Dispersed PdS Monolayer as a Potential Sensing Material for Dissolved Gas Analysis in Electrical Transformers: A First-Principles Study.

To perform the dissolved gas analysis in transformer oil, in this work, we propose the Ni-dispersed PdS (Ni-PdS) monolayer as a promising sensing material for three typical dissolved gases H, CO, and CH. For the Ni-dispersing process, we find that Ni atoms can be chemically stably adsorbed on the PdS surface with a binding energy of -4.11 eV. For gas adsorption systems, it is found that the Ni-PdS monolayer allows the physisorption of H molecules and the chemisorption of CO and CH molecules. Besides, the analysis of electronic properties of the Ni-PdS/gas system reveals its potential as a resistance-type H or CH sensor with sensing responses of -40.9 and 261.5%, separately, and the WF analysis indicates its low potential as a WF-based gas sensor for the three gases. These findings indicate the Ni-dispersed behavior on the PdS surface and the gas-sensing potential of the Ni-PdS monolayer, which we expect can facilitate more investigations about PdS-based materials for applications in gas adsorptions and sensing in some other fields.