Fabrication of uniform 1-D ZnO/ZnCo2O4 nano-composite and enhanced properties in gas sensing detection

Binary composite with heterostructure have received intense concerns in gas sensing domains. In this paper, we describe the design, fabrication, and gas-sensing tests of 1-D decorated-type ZnO/ZnCo2O4 nanocomposite, which is synthesized through a facile and eco-friendly solution-based process. A series of characterization methods are employed to evaluate the as-synthesized products, including X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and BET technique. The acetone gas-sensing properties of ZnO/ZnCo2O4 nanorods are evaluated with different acetone vapor concentrations at the working temperature of 240 °C. Among, the response of 1:1 ZnO/ZnCo2O4 nanorod based sensor displays a fascinating value ca. 15.3, which is superior to the sensor based on original ZnO nanorods. Gas test results also reveal that the sensor has fast response kinetics and good selectivity to acetone gas. A plausible sensing mechanism is also illustrated hereinafter, which we believe it can provide theoretical guidance for the further development of novel and advanced gas-sensitive materials with p-n heterojunction. As such, this binary nanocomposite (ZnO/ZnCo2O4) is a rather promising candidate to be applied into gas detection field.