Hydrothermal synthesis and characterization of core/shell ALOOH microspheres

The AlOOH core/shell microspheres were successfully synthesized via a one-step template-free hydrothermal route. By simply changing the ratio of alcohol to water, core/shell microspheres constructed with nanoplatelets and their curling structures could be selectively synthesized. A series of controlled experiments have also been carried out to better understand the formation mechanism of AlOOH spheres and the function of reactants used in the experiments. The formation of core/shell structures may involve aggregation of amorphous building clusters into spheres and their subsequent reaction, dissolution, and re-deposition process. The morphology, structure, and composition of the spheres are investigated using field-emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analysis. The specific surface area and pore-size distribution of the obtained product as determined by gas-sorption measurements show that the boehmite core–shell microspheres exhibit high Brunauer–Emmett–Teller (BET) surface area and porosity properties. The as-prepared AlOOH core–shell superstructures are powerful in the removal of Congo red pollutant from waste water.