Microwave assisted hydrothermal synthesis of single crystalline ZnO nanorods for gas sensor application

Single crystalline ZnO nanorods were synthesized via microwave assisted hydrothermal method using zinc hydroxide as starting material, cetyltrimethylammonium bromide (CTAB) as structure directing agents, and water as solvent. As synthesized ZnO was characterized using X-ray powder diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The SEM images showed that the diameter of the nanorods falls in the range of about 100-150 nm and length in the range of 1-2 μm. The TEM study showed that as prepared ZnO nanostructures are single crystalline in nature. Gas sensors were prepared and tested for the detection of CO (1000-200 ppm), ethanol and acetaldehyde (250-50 ppm) in air. Results demonstrate that as synthesized ZnO nanorods can be selectively used for the detection of ethanol at 200 °C testing temperature.