With the development of two-dimensional materials such as graphene, transition metal dichalcogenides (TMDs), MXenes and MBenes, these materials have received extensive attention from scholars in the field of gas sensing due to their unique and superior properties. Based on first-principles calculations, the adsorption energy, charge transfer, density of states and deformation charge density of CrB, an MBene successfully synthesized under laboratory conditions, were investigated for the adsorption of the decomposition components (CF₄, C₃F₆ and COF₂) of an insulating medium, C₄F₇N. The calculation results revealed strong chemisorption with an adsorption energy as high as −3.336 eV between CrB and COF₂, as well as physical adsorption with CF₄ and C₃F₆. However, the excessive interaction strength makes it difficult for COF₂ molecules to escape from the binding of the CrB substrate, making CrB more suitable as an adsorbent to remove COF₂ gas. Compared with COF₂ and CF₄, CrB has appropriate adsorption energy and charge transfer for C₃F₆ adsorption, and its theoretical recovery performance is acceptable, indicating its potential as a sensor for detecting C₃F₆.

GaN is an emerging 2D material with a wide direct bandgap and high carrier concentration. By using computational methods to introduce Ga defects in GaN, we have made a structure with extremely high chemical activity. After that, Ag, Pt, and Rh are used to repair Ga defects to reasonably suppress the overactive defect sites. In this way, the Ga defect GaN repaired by metal atoms was made. We used density functional theory for dispersion correction for calculation. Specifically, the Perdew–Berke–Ernzerhof generalized gradient approximation method was used. Through the analysis of geometric structure, adsorption energy, electron transfer, deformation charge density, density of states, and band structure, it was screened that Rh@GaN could effectively adsorb SOF2 (adsorption energy −0.78 eV) and be accompanied by a high electron transfer (0.186e). Finally, through the analysis of recovery time and sensitivity, it is verified that Rh@GaN can adsorb SOF2 with high selectivity at room temperature and can generate up to 191.75% response signal to SOF2.