First-principles investigation upon H2 and C2H2 adsorptions on the Ag-decorated InN monolayer for gas sensor development

Abstract This work using the first-principles theory investigates the adsorption behavior of Ag-decorated InN (Ag-InN) monolayer upon H2 and C2H2, in order to realize the dissolved gas analysis (DGA) in transformer oil. The Ag-decorating analysis indicates that the TN site is most energy-favorable with binding energy (Eb) of −1.26 eV. Physisorption is identified for H2 system while chemisorption for C2H2 system given the calculated adsorption energy (Ead) of −0.46 and −0.92 eV, respectively. Given the desirable C2H2 sensing response of 58.3% obtained by the frontier molecular orbital theory and the recovery property obtained by van’t-Hoff-Arrhenius expression, we conclude that Ag-InN monolayer is a promising recyclable resistance-type sensor for C2H2 detection at room temperature, while is not suitable for H2 detection because of the small sensing response and quite short recovery time. Our calculations can provide the guidance to explore novel sensing materials for application in the field of power system as promising gas sensors.