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

Abstract

β12 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 β12 borophene remains to be clarified. In this work, we study the interactions of β12 borophene towards five hazardous gases, namely, CO, NO, NH3, NO2, and CO2 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, CO2 is physisorbed while other gases are chemically bonded to β12 borophene. We also demonstrate that the deformation at the ridge of borophene enables its active pz orbital to strongly hybridize with frontier orbitals of the studied polar gases. Consequently, borophene is predicted to interact strongly with CO, NO, NH3, and especially NO2, making it a sensitive sensing material for toxic gases. This journal is