Perovskite nanoparticles decorated one-dimensional metal oxide scaffold toward highly selective and sensitive chemiresistors

Abstract

Perovskite oxide nanoparticles (NPs) functionalized SnO2 fiber-in-tubes (FITs) were easily fabricated by electrospinning and subsequent calcination. Here, $La_{0.75}Sr_{0.25}Cr_{0.5}Mn_{0.5}O_{3-\delta}$ (LSCM) perovskite oxide NPs were selected as catalysts for chemi-resistive gas sensors. After the calcination of as-spun nanofibers with fast ramping rate, LSCM NPs were tightly immobilized on $SnO_2$ FITs, which have large surface area and high porosity that are essential for chemi-resistive gas sensors. In addition, LSCM NPs, which have numerous surface oxygen adsorbed on the oxygen vacancies induced by cation substitution, can act as catalysts, providing surface oxygen to the surface of $SnO_2$ FITs at optimized sensing temperature (400 $\circ C$). From these structural and catalytic effect, LSCM NPs loaded $SnO_2$ FITs (LSCM@$SnO_2$ FITs) exhibited remarkable response (Rair/Rgas = 26.50 to 5 ppm) and excellent selectivity toward formaldehyde among various interfering analytes. Furthermore, the detection capability of formaldehyde of LSCM@$SnO_2$ FITs can be applied to real-time monitoring of indoor air quality.