Soft-template self-assembly of hierarchical mesoporous SrCO3 by low-temperature hydrothermal route and their application as adsorbents for methylene blue and heavy metal ions

Abstract

Toward the efficient and cost effective synthesis of three-dimensional hierarchical architectures at mild condition and their potential applications in environmental protection, the materials chemistry for green synthesis of strontium carbonate (SrCO3) superstructures and their application as adsorbents for methylene blue solution and heavy metal ions were explored. Uniform hierarchical mesoporous SrCO3 microspheres with a narrow diameter distribution were synthesized via a mild hydrothermal treatment (110°C, 6.0h) of the slurry derived from the room temperature coprecipitation of SrCl2 and Na2CO3 solution, in the presence of ethylenediaminetetraacetic acid (EDTA). The as-synthesized mesoporous SrCO3 microspheres had a specific surface area of 56.3m2g−1 and a narrow pore size distribution concentrating on 2–20nm, with an average pore diameter of 9.45nm. The introduction of EDTA in due case with tuned pH value was favorable for the formation of SrCO3 microspheres, whereas the mild hydrothermal treatment promoted the morphology uniformity of the mesoporous microspheres with narrow diameter distribution. The adsorption evaluation indicated that the present mesoporous SrCO3 microspheres exhibited excellent adsorption performance for deionized (DI) water containing methylene blue, or heavy metal ions such as Fe3+ and Pb2+, revealing the as-synthesized uniform hierarchical mesoporous SrCO3 microspheres as potential adsorbents with wide applications in environmental protection.