Superior NH3 Sensor Using Ni Doped K-OMS-2 Nanofibers

A room temperature reversible ammonia (NH
₃
) gas sensor based on the resistive transduction mechanism comprising of thin film of nickel doped cryptomelane octahedral molecular sieves of K-OMS-2 nanofibers is developed. Ni-OMS2 demonstrated excellent and persistent sensing toward the low concentration of ammonia in air at room temperature. The sensor showed strong response of 20% and 57% for 10 and 50 ppm of NH
₃
. No heating was required either for sensing or recovery. Doping concentration of Ni significantly affect the ammonia sensing properties of nanofibers. Low doping of 0.11 Ni
⁺²
in K-OMS-2 resulted in the major improvement in recovery time during ammonia sensing to 40s from 87s in undoped nanofibers. However, higher amount of Ni doping showed no response for ammonia sensing.