Sensors, Vol. 19, Pages 1903: Improved Sensitivity of ?-Fe2O3 Nanoparticle-Decorated ZnO Nanowire Gas Sensor for CO (Sensors)

A strategy for improving the sensitivity of a sensor for detecting CO and NH3 gases is presented herein. The gas sensor was fabricated from ZnO metal oxide semiconductor nanostructures grown via a vapor-liquid-solid process and decorated with ?-Fe2O3 nanoparticles via a sol-gel process. The response was enhanced by the formation of an ?-Fe2O3/ZnO n-n heterojunction and the growth of thinner wires. ZnO nanowires were grown on indium-tin-oxide glass electrodes using Sn as a catalyst for growth instead of Au. The structure and elemental composition were investigated using field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The gas sensing results indicate that the response value to 100 ppm CO was 18.8 at the optimum operating temperature of 300 °C.