Heteroatom‐doped Carbon Spheres from Hierarchical Hollow Covalent Organic Framework Precursors for Metal‐Free Catalysis

Abstract

Covalent organic frameworks (COFs) with hollow structures hold great promise for developing new types of functional materials. Herein, we report a hollow spherical COF with a hierarchical shell, which serves as an effective precursor of B,N-codoped hierarchical hollow carbon spheres. Benefiting from the synergistic effects of hierarchical porosity, high surface area, and B,N-codoping, the as-synthesized carbon spheres show prospective utility as metal-free catalysts in nitroarene reduction. A mechanistic hypothesis is proposed based on theoretical and experimental studies. Boron atoms situated meta to pyridinic N atoms are identified to be the main catalytic active sites. The anti-aromaticity originating from the codoping of B and pyridinic N atoms, not charge distribution and deformation energy, is confirmed to play a pivotal role in the catalytic reaction.

Collectively Exhaustive Electrodes Based on Covalent Organic Framework and Antagonistic Co‐Doping for Electroactive Ionic Artificial Muscles

“…Further, hierarchical porous nitrogen‐doped carbons, owing to their high specific surface area (SSA) and impressive electrical conductivity and electrochemical activity, have recently been used as electrodes for ultrasensitive bio‐inspired artificial muscles . Recently, heteroatom co‐doping in porous carbon is a growing avenue of research in the fields of supercapacitors and electrocatalysts . However, to the best of authors' knowledge, co‐doped porous carbon‐based electrodes for exploration of ionic soft actuators have not carefully been investigated to date by considering both direct current (DC) and alternating current (AC) input patterns.…”

“…With their high surface area, tunable compositions, and diverse structural topologies, they have been widely explored for catalysis, gas storage and separation, and proton conduction . These materials are outstanding templates for the preparation of heteroatom‐doped porous carbons via pyrolysis process owing to their ordered porous structures, regular arrangement of diverse heteroatoms such as B, O, N, and S, and high concentrations of carbon species . Notably, sulfur‐doped carbon is more beneficial compared to nitrogen due to its linkage to the electron‐rich aromatic sulfide, which offers more polarized surface under electric field leading to enhance dielectric constant of the electrolyte and assist the charge‐transfer process .…”

Covalent Organic Framework Derived Boron/Oxygen Codoped Porous Carbon on CNTs as an Efficient Sulfur Host for Lithium–Sulfur Batteries

“…The research strategies for carbon materials doped with heteroatoms (X = B, N, P, S, O, etc.) are particularly interesting because these heteroatoms not only effectively suppress the shuttle effect but also enhance the reaction activity of the sulfur. Among them, N‐doped porous carbons have been extensively studied and proven to effectively enhance the electrochemical performance of Li–S batteries .…”

Biomass Sucrose‐Derived Cobalt@Nitrogen‐Doped Carbon for Catalytic Transfer Hydrogenation of Nitroarenes with Formic Acid

“…To date, supported catalysts such as noble-metal catalysts, non-noble metal catalysts, and metal-free catalysts have been reported for catalytic hydrogenationo fn itroarenes. [4][5][6][7][8] For example, Doherty et al reported phosphine-decorated, polymer-immobilized, ionic-liquid-stabilized palladium nanoparticles (NPs) for highly efficient hydrogenation of nitroarenes. [9] Wang and co-workers fabricated heterogeneous nonnoble metal nickel-molybdenum oxide catalystss upported on ordered mesoporous silica SBA-15t hat exhibited excellent catalytic activity for catalytic hydrogenation of nitroarenes with hydrazineh ydrate as hydrogen donor.…”