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Hybrid mesoporous silica based on a hyperbranch-substrate nanonetwork as highly efficient adsorbent was explored by an efficient and facile approach combined with one-pot condensation and grafting-to methodology, including a terminated amino hyperbranched polymer (HBP) modification. The specific synthesis procedure involves the following steps: (i) premodification of SBA-15 via a co-condensation-hydrolysis route, obtaining carboxyl functionalized SBA-15 (SBA-CAR), and (ii) grafting HBP onto SBA-CAR by a grafting-to method, obtaining hybrid mesoporous silica (SBA-HBP). The main structural characteristics of SBA-15 are preserved in the resultant SBA-HBP, which exhibits high surface area, large pore volume, and well-ordered porosity made up of uniform mesopores. Due to its reusability and with a three-dimensional hyperbranch-substrate nanonetwork with substantial functional groups, the as-synthesized SBA-HBP is considered a versatile and sustainable adsorbent for dyes (i.e., methylene blue and congo red) and heavy metal ions (i.e., Cu2+ and Fe3+) from aqueous media with high adsorption capacity and quick adsorption rate. Also, the saturated adsorption capacities are 452.1 mg/g for MB, 593.4 mg/g for CR, 224.2 mg/g for Fe3+, and 158.7 mg/g for Cu2+, respectively.

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Amidoxime and hydroxamic acid functional groups have comparable chelating ability with synthetic resins, but the synthesis of cellulose fibers bearing amidoxime and hydroxamic acid functional groups using simple and effective strategies have yet to be developed. In this study, a poly(amidoxime-hydroxamic acid) cellulose derivative (pAHA-cellulose) was prepared via free radical polymerization followed by an oximation reaction. A series of microscopic analyses and spectral tests proved that the pAHA-cellulose was covered with uniform amidoxime and hydroxamic acid functional groups. The use of pAHAcellulose towards heavy metal ion removal was investigated and an uptake equilibrium was achieved within 60 min for Cu 2+ and Zn 2+ , and 120 min for Pb 2+ and Cr 3+, through a chelation mechanism. The adsorption behavior followed the pseudo-second-order kinetic model and Langmuir isotherm with and Zn 2+ , respectively. Regeneration of pAHA-cellulose did not significantly influence the adsorption towards metal ions for up to five sequential cycles. Considering the simple and efficient grafting process, excellent adsorbability and prominent renewability, pAHA-cellulose is believed to be a new and feasible candidate for heavy metal ion removal from aqueous solution.