Gas-Sensing Properties of Cu(2)S–MoSe(2) Nanosheets to NO(2) and NH(3) Gases

[Image: see text] Cu(2)S–MoSe(2) was selected as a gas-sensing material to detect NO(2) and NH(3). Based on density functional theory calculations, the adsorption structures, density of states, molecular orbit, and recovery time were studied to analyze the gas-sensing mechanism of Cu(2)S–MoSe(2) to gases. Calculation results show that Cu(2)S clusters receive a stable doping structure on the MoSe(2) surface. Compared with intrinsic MoSe(2), Cu(2)S–MoSe(2) shows more excellent adsorption performance to NO(2) and NH(3) due to the active feature of the Cu(2)S dopant. After NO(2) and NH(3) adsorption, the energy gap decreases, indicating an improvement of the conductivity, which is greatly significant for gas sensing. For double NH(3) adsorption, the conductivity of the entire system increases more than that of a double NO(2) adsorption system, signifying the sensitivity of Cu(2)S–MoSe(2) is greater for NH(3) than NO(2). The results of theoretical recovery time show that Cu(2)S–MoSe(2) is sensitive for NH(3) detection at room temperature (298 K) and NO(2) detection at high temperature (400 K).