Mesoporous microspheres of nickel-based layered hydroxides by aerosol-assisted self-assembly using crystalline nano-building blocks
Structural control in micro- and nanometer scales is necessary to design highly functional materials. Crystalline mesoporous microspheres (MMSs) are expected to improve electrochemical, catalytic, and adsorption performances. In this study, we focused on the preparation of templated MMSs of nickel-based layered hydroxides by using pre-crystallized nano-building blocks (NBBs). Layered nickel hydroxide nanoparticles were prepared through an epoxide-mediated alkalinization process and used as NBBs to construct microspheres. The spherical particles in micrometer scale were synthesized by an aerosol-assisted assembly of the NBBs dispersed in a solvent, in the presence of supramolecular templates. It was found that controlling the crystallization as well as the surface philicity permits to yield the NBBs with an adequately small size and interparticle interactions that generate self-assembled MMSs akin to those obtained in NBB-based mesoporous thin films. The preparation technique demonstrated here is highly versatile; templated MMSs with various chemical compositions of nickel-based layered double hydroxides were successfully obtained.
Synthesis of mesoporous microspheres composed of crystalline layered nickel hydroxide and layered double hydroxides is demonstrated.
Spray-drying was applied to colloidal suspensions of crystalline nano-building blocks for the synthesis.
Controlling the crystallization and surface philicity are important factors for the successful self-assembly.
The preparation technique demonstrated here is highly versatile and can be extended to various systems.
KeywordsCrystalline mesoporous microspheres Nano-building blocks Layered nickel hydroxides Layered double hydroxides Epoxide-mediated alkalinization
Strategic Young Researcher Overseas Visits Program for Accelerating Brain Circulation from JSPS is gratefully acknowledged. The present work was partially supported by JSPS KAKENHI, JSPS bilateral program, LNLS proposal SAXS1 18927, ANPCyT (PICT 2012-2087 and 2015-3526), UBACyT (20020130100610BA), Hitachi Metals Materials Science Foundation, The Sumitomo Foundation, and Izumi Science and Technology Foundation. We thank Mr. J. Daniels and Mr. S. M. Nikka for the helpful discussions.
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Conflict of interest
The authors declare that they have no conflict of interest.
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