Ultra-fast microwave irradiation: a superior method of fabricating ZnO quantum wires

Abstract

ZnO nanorods were successfully synthesized by the microwave irradiation method in this project. The procedure verified the highest yields, least expense, and fastest synthesis of pure, fine-grained, single-phase ZnO nanorods; additionally, the procedure is ecologically friendly. Same-scale size nanorods displayed varying d-spacing values with the Hold time changed at a constant temperature of 150 °C in the microwave reactor, as supported by the TEM results. HRTEM pictures verified the ZnO nanorods’ perfect form. The quality of the nanoparticles’ crystallization was demonstrated by SAED patterns and data. The hexagonal wurtzite structure of ZnO nanorods is further supported by the matching of the diffraction rings in the SAED image with the peaks in the XRD pattern. Based on the data analysis, we concluded that the d-spacing values in ZnO nanorods at various nanometer scales increased. The absence of diffraction peaks from other contaminants indicated a high level of purity in ZnO samples. All the diffraction peaks were in good arrangement with those of the hexagonal structure of ZnO. Only the elements zinc (Zn) and oxygen (O) appeared in the EDX data, and the mass fraction was calculated. In the UV–visible absorbance spectrum, the absorbance peak located at the wavelength of 376 nm was the characteristic peak for hexagonal wurzite ZnO. The bandgap for ZnO nanorods held for one minute at a constant temperature of 150 °C is 3.24 eV; the binding energy gap for samples maintained for five minutes is 3.25 eV; and the binding energy gap for samples held for fifteen minutes is 3.28 eV, as determined by the UV–vis data. The presence of a peak at 432 cm⁻¹ at 1 min Hold Time ZnO nanorods FTIR data, 434 cm⁻¹ in 5 min Hold time ZnO nanorods FTIR data, and 451 cm⁻¹ proved a characteristic vibration of the Zn–O bond in the wurzite structure of ZnO. Therefore, at a constant temperature of 150 °C, the distinctive peaks of ZnO nanorods increased with variations in hold duration.