A Facile Approach to Fabricate an N‐Doped Mesoporous Graphene/Nanodiamond Hybrid Nanocomposite with Synergistically Enhanced Catalysis

Abstract

Owing to their unique structural features and surface properties, graphene and nanodiamond have attracted tremendous attention in diverse fields. However, restacking of graphene and reagglomeration of dispersed nanodiamond inevitably depress their catalytic properties. Herein, inspired by the historic discovery of “pillared clay”, we successfully realized the simultaneous inhibition of their restacking by fabricating a N‐doped mesoporous graphene/nanodiamond (N‐RGO/ND) nanocomposite by a facile wet‐chemical approach. The electrocatalytic oxygen reduction reaction (ORR) and the thermocatalytic oxidant‐free and steam‐free direct dehydrogenation (DDH) of ethylbenzene were used to examine its catalytic properties. The nanocomposite showed synergistically improved catalytic DDH and electrocatalytic ORR activity relative to that of the individual components, which can be ascribed to synergy between graphene and nanodiamond and to the large surface area, well‐ordered mesoporous structure, small crystalline size, and rich defect and CO surface features. Moreover, the developed synthetic strategy in this work can be extended to diverse N‐doped nanocomposites from dispersion‐required carbon precursors.

Carbon Nitride Encapsulated Nanodiamond Hybrid with Improved Catalytic Performance for Clean and Energy-Saving Styrene Production via Direct Dehydrogenation of Ethylbenzene

“…39 Correlated to the HRTEM, BET, and XRD analyses, this is an indicator for the formation of loose carbon nitride layers close-wrapped on a ND hybrid, which is significantly different from the our previously reported M-ND hybrid. 36 Moreover, the remarkably higher I D /I G for the H-ND hybrid than the other two indicates the surface disordered carbon nitride and/or formed surface structural defects, 39,40,60,66 which gives further evidence for the presence of a great amount of carbon nitride. From FESEM images of the N-ND and the parent ND, no visible difference can be observed.…”

Nitrogen-doped carbon nanotubes via a facile two-step approach as an efficient catalyst for the direct dehydrogenation of ethylbenzene

“…[1][2][3][4][5][6] Carbon nanotubes, as one of the typical and commercially available nanocarbon materials, have been generally used as a support to fabricate supported metals and their derivatives catalysts for diverse reactions. [1][2][3][4][5][6] Carbon nanotubes, as one of the typical and commercially available nanocarbon materials, have been generally used as a support to fabricate supported metals and their derivatives catalysts for diverse reactions.…”

“…26 Thermal treatment refers to the method of heating carbon nanostructures in an ammonia atmosphere or pyrolysis of carbon materials with nitrogen-containing precursors to produce nitrogen-doped nanostructured carbon materials, 26,36,37 which has been considered to be a facile and scalable method to prepare nitrogendoped carbon materials. [3][4][5][33][34][35] Just like a coin has two sides, this type of pyrolysis method has its inherent disadvantage: high temperatures result in low doping levels due to the splitting of C-N bonds; however, low pyrolysis temperatures lead to a thicker CNx layer coating on carbon nanostructures, which may deteriorate their catalysis by inhibiting the reactants from reaching the surface active sites. Therefore, post treatment by heating is a facile and robust strategy to prepare metal-free nitrogen-doped carbocatalysts.…”

“…46,47 Correlated to the HRTEM results illustrated in Fig. [3][4][5][33][34] Therefore, XPS analysis was carried out to investigate the surface chemical properties of the as-prepared A-M-CNT, M-CNT and pristine CNTs. The PAA process possibly produces more surface oxygen, and therefore the surface oxygen can remove the CNx that View Article Online would be formed by the pyrolysis of melamine, which can increase the structural defects.…”

“…The PAA process possibly produces more surface oxygen, and therefore the surface oxygen can remove the CNx that View Article Online would be formed by the pyrolysis of melamine, which can increase the structural defects. [1][2][3][4][5][6] The surface phenolic hydroxyl group and/or possible COOH may promote the cracking of ethylbenzene due to its acidity, because acidic sites are active for facilitating the cracking reaction of hydrocarbons. In comparison with A-CNT, A-M-CNT has a little lower I D /I G ratio, which may be caused by the protective role of melamine.…”