Fluorination of shape-controlled porous carbon nanoweb layers for ammonia gas sensor applications

Abstract

Fluorinated porous carbon nanoweb layers (FPCNWLs) are simply fabricated by spin coating of adjusting polymer mixing ratio, sequential thermal treatments, and vacuum plasma treatment to enhance the specific surface area and to dope the fluorine into the carbon lattice. The different surface tension, polarity, and molecular weight of PAN and PS causes immiscible solution, therefore, the various size of pores on the carbon structure are constructed during the stepwise thermal treatment. Moreover, the F doping ratio is easily controlled with different plasma treating time. The fluorination causes both p-type doping and affinity toward ammonia gas. The fabricated FPCNWLs-based ammonia gas sensor devices demonstrate outstanding NH3 gas sensing performances that minimum detection level (MDL) of FPCNWLs-based ammonia gas sensor is 9 ppb using FPCNWL20 and the sensors display linear range from 9 ppb to 90 ppm. In conclusion, the FPCNWL20-based ammonia gas sensor demonstrates rapid response and recovery time, excellent cyclic stability, reusability, durability, and selectivity.