Journal of Materials Science, Vol.55, No.9, 3845-3859, 2020
Hollow Li2SiO3 architectures with tunable secondary nanostructures and their potential application for the removal of heavy metal ions
Li2SiO3 is a potential new material for mitigating environmental issues such as greenhouse effect and wastewater treatment, but the high-quality failure and evolvable morphology limit have restricted its large-scale application. Herein, a high-quality hierarchically hollow-structured Li2SiO3 assembled by tunable secondary structures was precisely fabricated by an efficient green and facile hydrothermal method. The secondary structures, from nanosheets to belts, thorns, spinule and eventually to nanoparticles, accompanying the corresponding morphologies evolving from peony-like to chrysanthemum-like, urchin-like, waxberry-like and eventually to spherical structures, could be tuned by adjusting precursors' Li/Si molar ratios. All of the obtained hollow Li2SiO3 structures were attributed to a common growth mechanism called inside-out Ostwald ripening. The as-prepared hollow Li2SiO3 structures were experimented as heavy metal adsorbents for the first time and exhibited excellent adsorption performance for all employed heavy metal ions (Cu2+, Mn2+ and Ni-)(2+). Furthermore, as a case study, the obtained heavy metal-bearing Li2SiO3 architectures (Cu(OH)(2)@Li2SiO3, MnO(OH)(2)@Li2SiO3 and Ni(OH)(2)@Li2SiO3) inherited the primary hollow morphology, which endowed them with reusability as high-efficient adsorbents for methylene blue by color removal efficiency higher than 98%. This work lays the foundation for the development of an environmentally friendly "two birds with one stone" route of "remover of heavy metal ions to dye adsorbent," which will be of great significance for the wastewater treatment.