Beyond SiO2：Controllable construction of spherical mesoporous metal oxides
Mesoporous metal oxides are of considerable scientific interest due to their broad functional properties and diverse potential industrial applications. Unfortunately, considering their distinctive sol-gel chemistry compared to silica, the decent control of inorganic-organic interactions and cooperative assembly of metal species and soft template is still a great challenge.
Recently, a research team led by Prof. WAN Lijun and CAO Anmin at the Institute of Chemistry, Chinese Academy of Sciences (CAS), demonstrated a kinetics-controlled process to realize the construction of spherical mesoporous metal oxides with systematically tailorable morphology and channel orientation.
Researchers initiated their study thorough adopting suitable precipitants to control the deposition speed for metal ions, using Al2O3 as a model system. The precisely-controlled pH value in the reaction system not only slows down the hydrolysis and condensation process of metal ions, but also controls the zeta potential of inorganic oligomers to maintain the electrostatic attraction with soft templates, resulting in the decent assembly and co-deposition of inorganic-organic species. The mesochannel orientation can be systematically tuned from random stacking, to radial orientation and concentric patterns, by regulating the interaction between metal ions and surfactants. In addition, this is a versatile strategy and can be readily extended to constructing mesoporous structures for various metal oxides, such as CeO2, La2O3, Cr2O3, Y2O3 and even composite oxides CexLayOz.
The study entitled "Spherical mesoporous metal oxides with tunable orientation enabled by growth kinetics control"was published in Journal of the American Chemical Society (DOI: 10.1021/jacs.0c07938).
The research work was financially supported by Key Research Program of Frontier Sciences, Chinese Academy of Sciences, Beijing National Laboratory for Molecular Sciences, Beijing Natural Science Foundation, and the National Natural Science Foundation of China.
Spherical mesoporous metal oxides with tunable pore orientation via kinetics-controlled process (Image by Prof. WAN Lijun and CAO Anmin)
Prof. CAO Anmin
Institute of Chemistry, Chinese Academy of Sciences