Theoretical insights into the two-dimensional gallium oxide monolayer for adsorption and gas sensing of C4F7N decomposition products

Designing prominent gas sensor materials for the detection of environmentally friendly insulating gas C4F7N decomposition products is a reliable strategy for diagnosing the operating state of insulation equipment. The gas sensing performance of the pristine and strained two-dimensional (2D) Ga2O3 towards C4F7N decomposition products has been assessed based on first-principles calculations. Analyses of changes in electronic structures and adsorption configuration indicate that 2D-Ga2O3 is an ideal gas sensor material for C3F6 by virtue of its evident selectivity, high sensitivity, excellent stability, and moderate adsorption strength. A new descriptor w is provided to explain the different gas sensitivity of Ga2O3 towards CxF2x gas with one carbon-carbon double bond. Besides, biaxial strain engineering is an eminent pathway to adjust the adsorption energy and sensitivity of 2D-Ga2O3 towards C3F6 by inducing local structural transformation of the adsorption configuration. These results not only suggest the prospects of pristine and strained 2D-Ga2O3 in gas sensor materials but also offer new insights into the selective detection of C4F7N decomposition products by 2D-Ga2O3.