Charged Nanowire-Directed Growth of Amorphous Calcium Carbonate Nanosheets in a Mixed Solvent for Biomimetic Composite Films.

Bio-inspired mineralization is an effective way for fabricating complex inorganic materials, which inspires us to develop new methods to synthesize materials with fascinating properties. In this article, we report that the charged tellurium nanowires (TeNWs) can be used as biomacromolecule analogues to direct the formation of amorphous calcium carbonate (ACC) nanosheets (ACCNs) in a mixed solvent. The effects of surface charges and the concentration of the TeNWs on the formation of ACCNs have been investigated. Particularly, the produced ACCNs can be functionalized by Fe3O4 nanoparticles to produce magnetic ACC/Fe3O4 hybrid nanosheets that can be used to construct ACC/Fe3O4 composite films through a self-evaporation process. Moreover, sodium alginate-ACC nanocomposite films with remarkable toughness and good transmittance can also be fabricated by using such ACCNs as nanoscale building blocks. This mineralization approach in a mixed solvent using charged TeNWs as biomacromolecule analogues provides a new way for the synthesis of ACCNs, which can be used as nanoscale building blocks for the fabrication of biomimetic composite films.

Bio-Inspired Synthesis of Hematite Mesocrystals by Using Xonotlite Nanowires as Growth Modifiers and Their Improved Oxygen Evolution Activity.

Bio-inspired synthesis of functional materials with highly ordered structure and tunable properties is of particular interest, but efficient approaches that allow the access of these materials are still limited. A method has been developed for the preparation of hematite particles by using xonotlite nanowires (XNWs) as growth modifiers. The concentration of the XNWs has a profound effect on the final morphology of the products, whereas the concentration of the iron(III) ions can control the size of the hematite particles. The underlying mechanism of the bio-inspired XNW-modified mineralization process has been proposed. The obtained hematite particles exhibit good catalytic performance in the oxygen evolution reaction (OER), affording a current density of 10 mA cm-2 with an overpotential of 370 mV, a small Tafel slope of 65 mV dec-1 , and good stability in alkaline electrolyte. This strategy for preparing functional materials by using nanowires as the growth modifiers has great potential for future application in the construction of various materials with hierarchical structures.