Controlled synthesis of various hierarchical nanostructures of copper sulfide by a facile microwave irradiation method

Hierarchical flower-like spheres and self-assembled chains of copper sulfide have been synthesized by a facile microwave irradiation. The as-obtained products were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectroscopy. The SEM and TEM results showed that three-dimensional (3D) flower-like CuS spheres are constructed by a number of two-dimensional (2D) nanosheets as primary building units, whereas the one-dimensional (1D) hierarchical chains are formed by the oriented attachment of the 3D flower-like spheres of CuS. The influences of the additive EDTA, concentration of reactants, microwave power, and reaction time on final morphology and assembled structure of the products were systematically investigated. On the basis of our experimental results, a phenomenological elucidation of the mechanism for the growth of the CuS architectures has been presented, and the driving force for the self-assembly of the nanoplates can be attributed to interfacial tension and the interaction between the hydrophilic surfaces of CuS nanoplates. EDTA acts as both a chelating reagent and a surface capping agent in the synthesis process. Moreover, the optical property of the flower-like CuS microspheres was measured by UV–vis absorption spectroscopy.