ZnO nanorods synthesized in large-scale via sonochemical method and its sensing potential towards methyl mercaptan

A novel and simple approach has been developed for a large-scale synthesis of ZnO nanorods using ultrasound radiation. Double-pod-like ZnO nanorods were directly grown from the starting precursors of zinc nitrate hydrate [Zn(NO ₃)₂6H₂O] and hexamethylene tetramine (HMT) in deionized water without any templates or seeds. The obtained double-pod-like product had a diameter ranging from 80 to 150 nm and length ranging from 1 to 5 um. Scanning electron microscope (SEM), X-ray diffraction (XRD) and transmission electron microscope (TEM) revealed that these products are of high purity, hexagonal and of single-crystalline structure. The ZnO nanorods synthesized were utilized for gas sensing application. Alumina plate consists of Pt interdigitated electrode was used as sensor substrate. The as-prepared products were transferred to the surface of substrate by screen printing method to fabricate the gas sensor. The sensing properties of the sensor were investigated toward methyl mercaptan (CH₃SH). The sensor shows good and fast response towards methyl mercaptan at a fixed operating temperature. The high sensitivity may be ascribed to the high surface area and aspect ration of the double-pod-like nanomaterial.