Planar-type BiCuVOx solid electrolyte sensor for the detection of volatile organic compounds

Mixed potential-type gas sensors with a BiCuVOx (Bi2Cu0.1V0.9O5.35) oxygen conductor, fitted with composite electrodes made of perovskite-type oxide (La0.6Sr0.4Co0.8Fe0.2O3) and BiCuVOx, were tested for their organic gas sensing properties. A planar-type BiCuVOx-based device, in which thin sensing electrode and thick counter electrode are attached, exhibited good sensing characteristics to low ethanol concentrations (4–30 ppm) at 400 °C. The electromotive force (EMF) of the device had a linear relation to the logarithm of ethanol concentration. The 90% response and recovery times of the device were short, i.e., less than 1 min. Moreover, the planar structure successfully eliminated any oxygen interference. The ethanol sensing mechanism is based on the mixed potential generation from the simultaneous anodic oxidation of ethanol and the cathodic reduction of oxygen, at the BiCuVOx/electrode interface.