Hierarchically structured LaFeO3 with hollow core and porous shell as efficient sensing material for ethanol detection

Hollow LaFeO3 (LFO-HS) was synthesized by a facile hydrothermal method with the use of cetyltrimethylammonium bromide. Its structural, morphological, microstructural and textual characterizations were performed using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption-desorption analysis. The gas-sensing performance of LFO-HS sensor was studied towards different gases, including ammonia (NH3), ethanol (C2H5OH), acetone (CH3COCH3), and liquefied petroleum gas (LPG). The LFO-HS sensor exhibited p-type gas sensing behavior and enhanced sensing performance towards ethanol gas as compared with bulk LaFeO3 sensor. A rapid, high, and stable response was seen at 300 °C. Meanwhile, a linear response and low limit of detection (1 ppb) to ethanol was observed. After the investigation on sensitivity to different reducing gases, our results revealed that the LFO-HS sensor exhibited good selectivity to ethanol and suggested it being a promising sensor candidate for future practical use in trace ethanol detection.