Rapid, repetitive and selective NO2 gas sensor based on boron-doped activated carbon fibers

[Display omitted] •Boron-doped activated carbon fiber effectively sensed to NO2 gas, repetitively.•Boron doping induced high selectivity toward NO2 via the strong binding energy.•The shallow, narrow and uniform pores on the surface worked as trap sites for NO2. In the current work, a high performance NO2 gas sensors has been fabricated from activated carbon fibers containing enriched boron moieties. The porous carbon fibers decorated with boron moieties exhibited rapid, repetitive and selective NO2 sensing performance at room temperature. The shallow, narrow and uniform micropores on the surface of the carbon fiber allowed target gases to be adsorbed and desorbed very easily whereas boron moieties induced high selectivity toward NO2 over NH3 via the strong binding energy. The excellent NO2 gas sensing performance of boron doped porous carbon fibers is attributed to synergetic effect of intrinsic pore structure of the carbon fibers and the boron moieties decorated on their surface.