Electrospun Ce–Ni–O composite nanofibers for highly selective propane detection at high temperature based on its rapid reaction kinetics†
Ce–Ni–O composite nanofibers (NFs) were successfully prepared by electrospinning and a subsequent calcination process. The morphology, composition and crystal structure of the as-prepared nanofibers were characterized in detail. Ce–Ni–O NFs, with a close to equal atomic ratio of Ce and Ni, possess an average diameter of 89 ± 10 nm. The backbone of nanofibers comprises well-distributed CeO2, highly dispersed NiO, and solid solution of Ce1−xNixO2. In addition, aggregated NiO nanoparticles with an average size of 25 ± 7 nm are also observed to decorate on the surface of nanofibers. The gas sensing performance of a Ce–Ni–O NF-based sensor towards CO, CH4 and C3H8 was investigated at 800 °C, which shows excellent sensitivity and selectivity towards C3H8. The sensing mechanism of the enhanced selectivity for C3H8 is proposed. Different reaction kinetics of different reducing gases on Ce–Ni–O NFs and the response offset effect of n-CeO2 and p-NiO on Ce–Ni–O composite nanofibers are ascribed to be responsible for the excellent selectivity to C3H8 over CO and CH4 under the tested conditions.