Rh-doped MoTe₂ Monolayer as a Promising Candidate for Sensing and Scavenging SF₆ Decomposed Species: a DFT Study

In this work, the adsorption and sensing behaviors of Rh-doped MoTe₂ (Rh-MoTe₂) monolayer upon SO₂, SOF₂, and SO₂F₂ are investigated using first-principles theory, wherein the Rh doping behavior on the pure MoTe₂ surface is included as well. Results indicate that T_Mo is the preferred Rh doping site with E_b of - 2.69 eV, and on the Rh-MoTe₂ surface, SO₂ and SO₂F₂ are identified as chemisorption with E_ad of - 2.12 and - 1.65 eV, respectively, while SOF₂ is physically adsorbed with E_ad of - 0.46 eV. The DOS analysis verifies the adsorption performance and illustrates the electronic behavior of Rh doping on gas adsorption. Band structure and frontier molecular orbital analysis provide the basic sensing mechanism of Rh-MoTe₂ monolayer as a resistance-type sensor. The recovery behavior supports the potential of Rh-doped surface as a reusable SO₂ sensor and suggests its exploration as a gas scavenger for removal of SO₂F₂ in SF₆ insulation devices. The dielectric function manifests that Rh-MoTe₂ monolayer is a promising optical sensor for selective detection of three gases. This work is beneficial to explore Rh-MoTe₂ monolayer as a sensing material or a gas adsorbent to guarantee the safe operation of SF₆ insulation devices in an easy and high-efficiency manner.