LDH nanocages synthesized with MOF templates and their high performance as supercapacitors

Abstract

Layered double hydroxides (LDHs) are currently attracting intense research interest for their various applications. Three LDH hollow nano-polyhedra are synthesized with zeolitic imidazolate framework-67 (ZIF-67) nanocrystals as the templates. The nanocages well inherit the rhombic dodecahedral shape of the ZIF-67 templates, and the shell is composed of nanosheets assembled with an edge-to-face stacking. This is the first synthesis of the LDH non-spherical structures. And the mechanism of utilizing metal-organic framework (MOF) nanocrystals as templates is explored. Control of the simultaneous reactions, the precipitation of the shells and the template etching, is extremely crucial to the preparation of the perfect nanocages. And the Ni-Co LDH nanocages exhibit superior pseudocapacitance property due to their novel hierarchical and submicroscopic structures.

Hierarchical Nanostructures: Design for Sustainable Water Splitting

“…Through this mechanism, LDH nanocages with different compositions, including Mg-Co, Ni-Co and Co-Co LDH, have been synthesized. [171] Interestingly, the reaction from ZIF to oxide/hydroxide can be reversed, which allows the templated synthesis of MOFs nanostructures. For example, as shown in Figure 9i, the zinc nitrate hydroxide nanosheets can be converted to ZIF-8 (zinccontaining ZIF) by immersing them in a 2-methylimidazole solution, and the ZIF-8 can be transformed back into LDH in Ni(NO 3 ) 2 or Co(NO 3 ) 2 solutions.…”

Co3O4 nanosheet-built hollow dodecahedrons via a two-step self-templated method and their multifunctional applications

“…Especially, ZIFs are often used as raw material to directly synthesize hollow nanostructures [13][14][15]. For example, Jiang et al [16] have synthesized ZnS hollow polyhedron with Zncontaining ZIF-8.…”

Transition metal oxides/hydroxides nanoarrays for aqueous electrochemical energy storage systems

“…Yuan et al [72] and Zhao et al [73] )), have attracted increasing interest from both academic and industrial angles due to their wide applications in various areas [74]. Recently, LDHs with vertically aligned structures have exhibited great potential in SCs [75][76][77][78]. Gu et al [79] prepared a NiTi-LDH nanosheet film by a two-step hydrothermal process, which showed a high areal capacitance of 10.37 F cm −2 at 5 mA cm −2 .…”