Highly efficient VOC gas sensors based on Li-doped diamane

Abstract

Volatile organic compounds (VOCs) are typical air pollutants harming the environment and human health, at present, the VOC detection is an essential challenge in environmental managements. In this work, the adsorption behaviors and detection performances of six typical VOCs are investigated on fluorinated diamond monolayer (F-diamane) by first principles calculation, to search the possibility of F-diamane in VOC detection at room temperature. The critical temperature of VOC desorption (292–504 K) increases after Li doping into F-diamane, attributed to the significantly enhanced adsorption capability of VOCs (adsorption energy increases 64–352%, interlayer distance reduces 2–22%, and transferred charge enhances 15–130%), which is also denoted by the partial density of states, and charge density difference. More importantly, the composite material exhibits high sensitivity and reversibility, caused by the increased electric conductivity and moderate adsorption energy. Consequently, Li-doped F-diamane is a promising trichloroethylene (C2HCl3) sensing material at room temperature. The results open a new avenue for designing diamane-based gas sensors.