Y4Al2O9 hierarchically nanostructured microspheres assembled with nanosheets: Microwave-solvothermal synthesis combined with thermal treatment and photocatalytic property

We have developed a microwave-solvothermal synthesis combined with thermal treatment method for the preparation of Y4Al2O9 hierarchically nanostructured microspheres assembled with nanosheets. First, a simple microwave-assisted solvothermal method is used to prepare the precursor using Y(NO3)3 and Al(NO3)3 at 200 °C in mixed solvents of water and N,N-dimethylformamide (DMF) without any surfactant. Then, thermal treatment of the precursor at 900 °C in air for 2 h is performed to obtain Y4Al2O9 hierarchically nanostructured microspheres, during which the morphology of the precursor can be well preserved. The samples are characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. The photocatalytic activity of as-prepared Y4Al2O9 hierarchical microspheres over phenol is investigated and the degradation rate of phenol is up to 91.2% in a period of 240 min.