Fabrication of a Spherical Superstructure of Carbon Nanorods

Abstract

superstructure with a large radius of curvature, such as spherical organization, is still a challenge. So far, only a few kinds of 1D oxides could be assembled into 3D spherical superstructures. [13][14][15] Low-dimensional carbon nanomaterials have been widely used in energy storage and conversion owing to their distinct electrochemical properties and mechanical and thermal stability. [16][17][18] 3D superstructures constructed from lowdimensional components such as carbon nanorods/wires or graphene nanorribbons can inherit the exceptional properties of their building blocks and acquire certain unconventional advantages. [19,20] However, the self-assemblies of 1D carbon nanomaterials into 3D ordered spherical superstructures are considerably challenging owing to the reduced accessible contact areas between the building blocks and core templates. Although various synthetic approches have been developed for the synthesis of lowdimensional carbon nanostructures with well-defined size and controllable composition, [21][22][23] no techniques have been applied for controlling the assembly of 1D carbon nanomaterials into 3D spherical superstructure with uniform morphology.Metal-organic frameworks (MOF) are a class of porous crystalline materials that are constructed by metal ions/clusters and organic linkers. [24] The use of MOF as a template or precursor to synthesize carbon nanostructure is an efficient approach to produce carbon materials with controlled morphology and Hierarchical superstructures in nano/microsize have attracted great attention owing to their wide potential applications. Herein, a self-templated strategy is presented for the synthesis of a spherical superstructure of carbon nanorods (SS-CNR) in micrometers through the morphology-preserved thermal transformation of a spherical superstructure of metal-organic framework nanorods (SS-MOFNR). The self-ordered SS-MOFNR with a chestnut-shell-like superstructure composed of 1D MOF nanorods on the shell is synthesized by a hydrothermal transformation process from crystalline MOF nanoparticles. After carbonization in argon, the hierarchical SS-MOFNR transforms into SS-CNR, which preserves the original chestnut-shell-like superstructure with 1D porous carbon nanorods on the shell. Taking the advantage of this functional superstructure, SS-CNR immobilized with ultrafine palladium (Pd) nanoparticles (Pd@SS-CNR) exhibits excellent catalytic activity for formic acid dehydrogenation. This synthetic strategy provides a facile method to synthesize uniform spherical superstructures constructed from 1D MOF nanorods or carbon nanorods for applications in catalysis and energy storage. 3D SuperstructuresHierarchical superstructures are ubiquitous in the biological systems (e.g., proteins, lipids, and carbohydrates). From the aspect of synthesis, self-assembly of simple building blocks into 3D, highly ordered superstructure with novel properties has attracted great interest in the fields of optics, catalysis, and energy storage. [1][2][3][4] Highly organized building bloc...

Seed-mediated evolution of hierarchical metal–organic framework quaternary superstructures

“…23,24 Multiple research groups found that morphologies of MOF-74 could be altered by controlling the synthetic conditions, including chestnut-shell structures, superlong nanotubes, hollow tubes, ripened multichannel tubes and helical tubular structures. [25][26][27][28] Very recently, we found that by choosing a N,N-dimethylformamide (DMF) solvent as the reaction medium, the assembly of hierarchical superstructures could be accelerated, generating MOF-74 spherulites as a nal product (Fig. 1b).…”

MOF‐Mediated Fabrication of a Porous 3D Superstructure of Carbon Nanosheets Decorated with Ultrafine Cobalt Phosphide Nanoparticles for Efficient Electrocatalysis and Zinc–Air Batteries

“…Three‐dimensional superstructures with specific morphologies and functionalities have received substantial attention in chemistry and material science due to their potential applications [1–3] . In comparison with isolated building blocks (nanoparticles, nanorods, nanosheets, etc.…”

“…Three-dimensional superstructures with specific morphologies and functionalities have received substantial attention in chemistry and material science due to their potential applications. [1][2][3] In comparison with isolated building blocks (nanoparticles, nanorods, nanosheets, etc. ), which suffer from poor total conductivity, [4] well-defined arrangement of these nanostructures into 3D integrative networks of superstructures can show simultaneous electrical conductivity and porous channels for effective mass transport with retained their own functionality.…”

A Hydrangea‐Like Superstructure of Open Carbon Cages with Hierarchical Porosity and Highly Active Metal Sites

“…[18][19][20] They have been used as precursors/templates for the synthesis of functional carbons and metal/ carbon composites with various controlled morphologies/structures and functionalities, showing a great potential in catalysis. [21][22][23][24][25] Generally, carbonization of MOFs produces collapsed structures or isolated carbon nanoparticles with insufficient contact and total conductivity. Thus, the transformation of MOFs into an active site-decorated carbon structure with simultaneous electrical conductivity and porous channels for fast electron transfer and effective mass transport, particularly in a self-templated or noncasting fashion, presents a major challenge.…”