Polyethylene imine functionalized porous carbon framework for selective nitrogen dioxide sensing with smartphone communication

Highly selective and remotely communicable nitrogen dioxide(NO_(2))sensing may contribute to future Internet of Things in environmental monitoring.However,room-temperature NO_(2)sensing materials such as carbon materials is still less than satisfactory due to their insensitive interaction with target gas.Here,polyethylene imine functionalized three-dimensional(3D)carbon framework(PEI/C framework)has been developed for enhanced selective NO_(2)sensing,via combined template synthesis and subsequent doping.Typically,the 3D PEI/C framework is observed porous shape with irregular coating.Beneficially,the response of C framework to NO_(2)increases while those of interfering gases decrease after being functionalized with PEI.Remarkably,the sensor prototypes show a 100 ppb-concentration detection limit at room temperature.Theoretically,such excellent NO_(2)sensing is attributed to the large specific surface ratio of porous 3D PEI/C framework,in which PEI serves as an active layer for target NO_(2),while a passivated one for interfering gases.Practically,such PEI/C framework sensor prototype is simulated for NO_(2)sensing device and communicated with a smartphone,showing great potential in future intelligent environmental monitoring.