Synthesis of spindle-like Co-doped LaFeO3 porous microstructure for high performance n-butanol sensor

With the growing concern on environmental protection, gas sensors based on metal oxide semiconductor (MOS) have recently attracted much interest owing to their great potential in detecting various flammable and harmful gases. Here, we report the synthesis of perovskite-type Co-doped LaFeO3 (CoxLaFe1-xO3, x = 0.00, 0.01, 0.05, and 0.10) spindle-like porous microstructures (SPMSs) via a facile co-precipitation and calcination method and their remarkably improved gas sensing performance to n-butanol. The prepared CoxLaFe1-xO3 SPMSs are about 0.2 similar to 2 um in length and constructed by crystalline secondary nanoparticles with the size around 50 nm, on which a lot of in situ nanopores were created during the decomposition of oxalate precursor. After doping with an optimized amount of Co, the LaFeO3 sensor showed remarkable improvements in n-butanol sensing performance, especially of lower optimal operating temperature, higher response, better selectivity, lower detection limit and faster response/recovery speed. Even to sub-ppm n-butanol (0.3 similar to 1 ppm), the sensor based on Co0.05LaFe0.95O3 SPMSs can give a sensitivity as high as 10.3/ppm. These characteristics make it a promising candidate for fabricating high performance n-butanol sensor. The possible mechanism for the improved n-butanol sensing performance was discussed.