Ab initio study of CNT NO<inf>2</inf> gas sensor

Abstract

NO2 gas adsorption, diffusion, and reaction on a single walled carbon nanotube (SWNT) surface are studied using ab initio simulations. The small diffusion barriers of NO2 on SWNT surface suggest that NO 2 molecules can produce NO and NO3 through chemical reactions. From the estimation of diffusion barriers and binding energies of NO2, NO, and NO3 on a SWNT surface, we show that NO 3 is the most likely long-lived species on SWNT. This finding enables us to explain why the experimental recovery times of NO2 gas sensors have been measured to be as long as 12 h. © 2004 Elsevier B.V. All rights reserved.