Electrospun Ce–Ni–O composite nanofibers for highly selective propane detection at high temperature based on its rapid reaction kinetics

Abstract

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 Ce_1−xNi_xO₂. 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.