Design of mesoporous Carbon/SnO2 micro/nanostructured ethanol sensors

Abstract

The low cost and convenient preparation of ZIF-8 derived mesoporous carbon polyhedrons (MPCPs) are introduced into SnO2 nanoparticles, and MPCPs/SnO2 composites with unique porous polyhedral micro/nanostructure are synthesized. The gas-sensitive investigations of the MPCPs/SnO2 sensor show that the sensitivity towards ethanol is significantly improved. The response of MPCPs/SnO2 sensor is approximately 79.5 towards 100 ppm ethanol at 160 °C, which is 3.5 times that of pure SnO2 sensor, and the response/recovery time are 17 s/38 s. In addition, the MPCPs/SnO2 sensor is significantly less cross-sensitive to other interfering gases. The enhancement of gas sensing performance is mainly attributed to the synergistic effect of high porosity, large specific surface area and abundant electrochemically active region of the MPCPs/SnO2 micro/nanostructure. Therefore, the synergy of the above factors provides the basis for improving the sensitivity and reducing the response/recovery time of the MPCPs/SnO2 sensor. The study provides technical guidance for designing ethanol sensors with higher sensitivity, shorter response/recovery time and lower cross-sensitivity.