Three-dimensional porous carbon framework coated with polyaniline for highly stable and selective ammonia sensing

Ammonia (NH3) sensing for environmental pollution monitoring is simultaneously required high selectivity against interfering gases, long-term stability with humidity tolerance and low detection limit, which needs further exploring. Here, the compositions of three-dimensional (3D) porous carbon framework (C-FW) coated with polyaniline (PANI@3D C-FW CPs) have been developed for highly selective and stable NH3 detection, which have been firstly prepared 3D C-FW via freezing/drying, and have been then in-situ coated with PANI. As synthesized PANI@3D C-FW CPs present 3D porous architectures with rough surface. Beneficially, the PANI@3D C-FW CPs show a distinguished selectivity to NH3 against other interfering gases and possess 100 ppbconcentration detection limit at room temperature (-25 degrees C), respectively. Remarkably, the PANI@3D C-FW CPs sensor prototypes show outstanding cycling stability to 10 ppm NH3 , and 249-day long stability. Theoretically, such outstanding NH3 sensing performance might be attributed to the unique deprotonation/protonation process of PANI molecules layer and the abundant adsorption sites of 3D porous framework structure. Practically, simulation to detect NH3 using as-prepared PANI@3D C-FW CPs has been conducted with reliable sensing response.