Improvement of the Structural and Chemical Properties of Carbon Nano‐onions for Electrocatalysis

Abstract

Heteroatom doping of carbon nanostructures is a convenient tool to control their physicochemical properties and to make them suitable for various applications. Carbon nano‐onions (CNOs) doped with nitrogen (N‐CNOs) have been prepared by annealing aminated‐nanodiamond particles (AM‐NDs) at different temperatures (1150, 1450 and 1650 °C) in an inert He atmosphere. Their physicochemical properties were compared with those of pristine CNOs obtained from non‐functionalized NDs under the same experimental conditions. The carbon nanostructures were characterized using transmission (TEM) and scanning (SEM) electron microscopy, X‐ray powder diffraction (XRD), Raman and Fourier transform infrared (FTIR) spectroscopy, porosimetry, and differential‐thermogravimetric analyses (TGA‐DTG). Their physicochemical properties are systematically discussed for undoped and for the nitrogen‐doped CNO samples. The results reveal that the surface morphology and the structure of undoped and nitrogen‐doped CNOs vary with the annealing temperature. All of these materials were electrochemically tested as electrode materials for enzyme‐free catalysis of hydrogen peroxide. The nitrogen‐doped carbon nanostructures have a higher catalytic activity than undoped nanostructures obtained under the same experimental conditions.

Carbon Nano‐Onions: A Review of Recent Progress in Synthesis and Applications

“…Nitrogen-doped CNOs (NÀ CNOs) have been prepared by annealing aminated-NDs (AM-NDs) at different temperatures (1,150, 1,450 and 1,650°C) in an inert He atmosphere. [150] HR-TEM investigations showed that NÀ CNOs have polygonal structures rather than spherical structures. This method allows for maintaining the π-conductive surface of CNOs, which is crucial for their applications in electrochemistry and electronics.…”

“…Boron‐doped CNOs (B‐CNOs) were obtained using an in situ method during electron irradiation of a graphitic material in a TEM and via chemical vapour deposition of BCl 3 and C 6 H 6 ,. The direct preparation of CNOs via thermal annealing of NDs using a boron source (H 3 BO 3 or amorphous powder of boron) or nitrogen was recently reported ,. A limited amount of boron species can be incorporated into the CNO structure (max.…”

“…Nitrogen‐doped CNOs (N−CNOs) have been prepared by annealing aminated‐NDs (AM‐NDs) at different temperatures (1,150, 1,450 and 1,650 °C) in an inert He atmosphere . HR‐TEM investigations showed that N−CNOs have polygonal structures rather than spherical structures.…”

“…Nitrogen‐doped CNs have interesting electrochemical and electrocatalytic properties and are frequently used in energy and sustainability applications ,. A GC electrode modified with pristine‐ or N−CNOs formed at different temperatures was used as a catalyst for the non‐enzymatic detection of hydrogen peroxide . It was observed that N‐doped samples had a higher catalytic activity than undoped CNOs prepared at the same temperature.…”

“…[145,146] The direct preparation of CNOs via thermal annealing of NDs using a boron source (H 3 BO 3 or amorphous powder of boron) or nitrogen was recently reported. [147,150] A limited amount of boron species can be incorporated into the CNO structure (max.…”