title: Synthesis and Adsorption Properties of Hierarchically Ordered Nanostructures Derived from Porous CaO Network.
abstract: Using the porous framework of CaO as templates and reagents, we explored a surfactant-free and economical method for preparing calcium silicate hydrate (CSH) hierarchically ordered nanostructures. Incorporation of SiO2nanoparticles into the CaO framework, followed by a reaction assisted by hydrothermal treatment, resulted in the formation of CSH with well-defined morphologies. The structural features of CSH were characterized by 3-D hierarchical networks, wherein nanofibers assembled to form nanosheets, and nanosheets assembled to form hierarchically ordered structures. Investigation of the crystal growth mechanism indicated that the key to forming the CSH ordered assembly structure was confining the Ca/Si ratio within a small range. Nonclassic oriented aggregation mechanism was used to describe the crystal growth of nanosheets, while the porous CaO framework served as template/reagents responsible for the formation of hierarchical structures. The resulting CSH adsorbent exhibited better performance in removing Pb(II) compared with other types of random CSH adsorbents. Additionally, the hierarchical structure of CSH provided more pores and active sites as support for other active functional materials such as zerovalent iron (Fe0). As-produced CSH@Fe nanocomposite with self-supported structures displayed high capacities for removal of Pb(II) after five adsorption-desorption cycles, and high capacities for other heavy metal ions (Cu2+, Cd2+, and Cr2O72-) and organic contaminants.
authors.affiliation: Key Laboratory of Eco-materials Advanced Technology (Fuzhou University), Fujian Province University , Fujian Province 350108, China.|College of Materials Science and Engineering, Fuzhou University , New Campus, Fujian Province 350108, China.
authors.forename: Weijie
authors.initials: W
authors.lastname: You
authors.affiliation: Key Laboratory of Eco-materials Advanced Technology (Fuzhou University), Fujian Province University , Fujian Province 350108, China.|College of Materials Science and Engineering, Fuzhou University , New Campus, Fujian Province 350108, China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Weng
authors.affiliation: Key Laboratory of Eco-materials Advanced Technology (Fuzhou University), Fujian Province University , Fujian Province 350108, China.|College of Materials Science and Engineering, Fuzhou University , New Campus, Fujian Province 350108, China.
authors.forename: Xiu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Eco-materials Advanced Technology (Fuzhou University), Fujian Province University , Fujian Province 350108, China.|College of Materials Science and Engineering, Fuzhou University , New Campus, Fujian Province 350108, China.
authors.forename: Zanyong
authors.initials: Z
authors.lastname: Zhuang
authors.affiliation: Key Laboratory of Eco-materials Advanced Technology (Fuzhou University), Fujian Province University , Fujian Province 350108, China.|College of Materials Science and Engineering, Fuzhou University , New Campus, Fujian Province 350108, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yu
keywords: Hierarchically ordered structure; calcium silicate hydrates; oriented aggregation; porous CaO framework; surfactant-free