Abstract

Hierarchical Co₃O₄ nanorods are prepared by effective hydrothermal strategy. The morphology and structure of the hierarchical nanostructures are characterized by means of field emission scanning electron microscope, high-resolution transmission electron microscopy and X-ray diffraction. The as-prepared Co₃O₄nanorods with the diameters about 200 nm are composed of small nanorods with average sizes of 20 nm. The gas-sensing properties of synthesized nanorods are tested to ammonia. Results reveal that hierarchical Co₃O₄ nanorods have excellent sensing performance. Moreover, the sensor consisting of hierarchical Co₃O₄nanorods exhibits high response and fast response/recovery speed to ammonia gas, while the sensor made of normal Co₃O₄nanorods do not exhibit notable response to ammonia gas. Significant enhancement of the sensing performance is attributed to the unique hierarchical nanostructure and good catalytic activity of Co₃O₄ nanomaterials.

Keywords

• Co₃O₄; 

• Rod-like hierarchical structures; 

• Gas sensor; 

• Fast response