Gas sensor based on MOFs-derived Au-loaded SnO2 nanosheets for enhanced acetone detection

The development of high response, low detection limit and low-cost acetone sensors remains a great challenge so far. In this work, the high-performance acetone sensors based on Au nanoparticles (NPs)-loaded SnO2 porous nanosheets were successfully synthesized via metal-organic frameworks (MOFs) template method, which synthesis method is facile and meets the requirements of large-scale production. The acetone sensing characteristics of pristine SnO2 and Au-SnO2-based sensors are investigated. The optimized Au-SnO2-based sensor exhibits high response to acetone (Ra/Rg = 18.2 @100 ppm at 240 °C) with high selectivity and fast response/recovery time compared with that of pristine SnO2. Importantly, a fully reversible resistance signal with a low acetone concentration (1 ppm) can be detected, and the theoretical detection limit of the sensor is as low as 40 ppb. Finally, the enhanced acetone sensing performance of the Au-SnO2 sensor can be attributed to the increased specific surface area and chemically adsorbed oxygen, as well as the formation of Schottky junction between the Au and SnO2 interfaces.