La0.67Sr0.33MnO3 nanofibers for in situ, real-time, and stable high temperature oxygen sensing

Abstract

By calcining electrospun La(NO₃)₃–Sr(NO₃)₂–Mn(NO₃)₂–PVP precursory nanofibers, La_0.67Sr_0.33MnO₃ (LSMO) nanofibers have been successfully fabricated on a large scale. The as-prepared LSMO nanofibers with an average diameter of ∼126 nm displayed a homogenous perovskite phase with a rough surface and porous structure. The LSMO nanofibers were thermally stable in terms of composition and crystalline structure after multiple heating/cooling cycles between room temperature and 1000 °C, accompanied by a slightly increased grain size. The LSMO nanofibers were applied for in situ real-time oxygen sensing at 800 °C and showed sensitive, reversible and reproducible response towards oxygen with a detection limit as low as 3.5 ppb (S/N = 3). These results suggest that electrospun LSMO nanofibers are a promising nanomaterial for the design and fabrication of stable high temperature gas sensors.