Synthesis of Boehmite Hollow Core/Shell and Hollow Microspheres via Sodium Tartrate-Mediated Phase Transformation and Their Enhanced Adsorption Performance in Water Treatment

Abstract

A variety of boehmite hollow core/shell and hollow microspheres with high adsorption affinity toward organic pollutants in water were prepared via a facile one-pot hydrothermal method using aluminum sulfate as a precursor and urea and sodium tartrate as precipitating and mediating agents, respectively. These microspheres were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption. In addition, the aforementioned microspheres were examined as potential adsorbents for Congo red and phenol from aqueous solutions. This study shows that the crystallinity, specific surface area, and pore structure of the resulting microspheres can be controlled by varying the concentration of sodium tartrate and reaction time. The reported experiments allowed us to propose the mechanism of formation of hollow core/shell and hollow microspheres, which involves sodium tartrate-mediated phase transformation, followed by a subsequent self-assembly process. ...