Highly sensitive ethanol chemical sensor based on nanostructured SnO2 doped ZnO modified glassy carbon electrode

Abstract

Chemical sensors represent an essential strategy for the monitoring of environmental constituents at low level exposures, but are often limited by relatively low sensitivity and slow response time. Here we report highly crystalline SnO2 doped ZnO framework with a cave-shaped porous nanostructure synthesized by a facile chemical approach as a high performance ethanol chemical sensor. A simple sensing system in solution is established using the modified glassy carbon electrode and applying the current–potential (I–V) and cyclic voltammetry techniques. With unique pore channels and small crystallite size, efficient electron and ion transport occur, leading to a remarkable sensitivity of 62.56μAcm−2mM−1 which is, to our knowledge, 9 orders of magnitude higher than those previously reported. The calibration plot is linear (r2=0.9887) over ethanol concentration range 0.195–25mM, with a limit of detection 0.137mM. The interaction of ethanol is a diffusion dominated with fast electron-transfer kinetics. The findings can open up exciting opportunities to fabricate highly efficient chemical sensors.