Thermal stability of NO on Ga-doped graphene and effect of external electric field

In this work, Ga-doped graphene with externally applied electric field was evaluated for NO gas sensing. In particular, density functional theory and ab initio molecular dynamics calculations were carried out to study the thermodynamic properties and thermal stability of NO adsorbed on Ga-doped graphene to reveal the feasibility of NO detection. The desorption temperature and desorption time were determined by thermodynamic method and chemical kinetic theory. To explain the adsorption/desorption mechanism, the structural parameters, charge transfer and electronic properties were analyzed and discussed. The results showed that NO would be desorbed from Ga-doped graphene when the temperature was higher than 580 K. It was also found that the highest working temperature of a Ga-doped graphene sensor for NO detection would be 445 K, assuming that the response time of the sensor is of the order of a microsecond. The adsorption configurations and electronic properties of interaction between NO and Ga-doped graphene can be noticeably enhanced by applying an electric field, so that the adsorption energy and desorption temperature are both increased. The results in this study provide a new strategy to regulate the adsorption/desorption process of NO on Ga-doped graphene, making it possible to be used as NO gas sensor.