Silicon Oxycarbide-Derived Carbon as Potential NO2 Gas Sensor: A First Principles’ Study

Silicon oxycarbide (SiCO)-derived porous carbon is a novel class of nano-porous material with unique properties including highly sensitive gas detection. In this letter, SiCO-derived porous carbon (porous SiCO) structures are successfully reproduced by simulating the etching process in experiments. Then, the gas sensing performance of SiCO-derived carbon with different porous morphologies is investigated. The calculated adsorption energy, Mulliken charge transfer, bandgap, and adsorption distance indicate that SiCO-derived porous carbon exhibits a higher sensitivity toward NO₂ gas than CO, ₂, and acetone in accordance with experimental conclusions. Moreover, the porous SiCO with the largest SSA and PV shows the most excellent NO₂ sensing performance. The adsorption of NO₂ leads to the appearance of a new strong peak at the edge of the conduction band, resulting in obvious changes of the conductivity of the systems, which is necessary for NO₂ detection.