▎ 摘　　要

Purpose - Graphene is a two-dimensional material. Its use has many advantages in gas sensing, but its long desorption process is problematic. The aim of this paper is to design a graphene-based gas sensor, study the response to NO2 gas concentrations and find ways to accelerate the desorption process. Design/methodology/approach - In one group, the sensor was placed in air to measure its initial resistance. Then, it was exposed to the NO2 gas at a certain concentration. Finally, the sensor was exposed to light immediately after NO2 gas exposure was ended. In another group, the sensor was heated using a heating plate at a stable temperature, before taking the measurements. Then the adsorption and desorption experiments were carried on. Findings - Illumination and heating at a suitable temperature can expedite desorption of NO2 molecules on graphene. Originality/value - In the paper, two main methods are introduced to accelerate the desorption process when the NO2 gas is absorbed on graphene. Through a series of experiments and analysis, the authors found that the recovery time could be reduced observably and the recovery performance of the graphene-based NO2 sensor could be improved effectively.