Adsorption of toxic gases on borophene: surface deformation links to chemisorptions

β(12) borophene has received great attention because of its intriguing mechanical and electronic properties. One of the possible applications of borophene is gas sensing. However, the interaction between common gases and β(12) borophene remains to be clarified. In this work, we study the interactions of β(12) borophene towards five hazardous gases, namely, CO, NO, NH(3), NO(2), and CO(2) using various non-empirical van der Waals density functionals and provide an insight into the adsorption behavior of borophene. The adsorption mechanism and molecular vibrations are discussed in great detail. Among the gases considered, CO(2) is physisorbed while other gases are chemically bonded to β(12) borophene. We also demonstrate that the deformation at the ridge of borophene enables its active p(z) orbital to strongly hybridize with frontier orbitals of the studied polar gases. Consequently, borophene is predicted to interact strongly with CO, NO, NH(3), and especially NO(2), making it a sensitive sensing material for toxic gases.