Morphology-Dependent Gas Sensing Properties of CuO Microstructures Self-Assembled from Nanorods

Materials with special microstructures provide excellent properties. In this study, three types of CuO microstructures with shrimp, flower, and urchin-like morphologies were synthesized via self-assembly of nanorods with a diameter of 30-50 nm using one-step hydrothermal synthesis method simply by adjusting the experimental parameters. At the same time, structural properties of the obtained materials were characterized using SEM, XRD, TEM, XPS, TGA and N₂ adsorption-desorption isotherms. The self-assembly mechanism was studied in detail, and a corresponding self-assembly strategy was proposed, which could guide the synthesis of other materials and may improve the potential of self-assembled crystalline materials in practical applications. Meanwhile, the gas sensing characteristics of three different gas sensors for volatile organic gases (methanol, ethanol, isopropanol, formaldehyde, ethyl acetate, acetone and triethylamine) were studied. The shrimp-like CuO sensor showed a higher sensitivity, shorter response time (21 s) and recovery time (19 s) than other sensors due to its higher specific surface area and special surface structure. At 200 °C, its response was upto 8.9 for 100 ppm triethylamine. This material has good application in the field of sensing.