Influence of nitrogen precursors on the structure, composition, and oxygen reduction reaction performance of dual heteroatom doped carbon nanohorns

Abstract

Heteroatom doped single-walled carbon nanohorns are produced via a facile one-step arc discharge method and used as metal-free catalysts for the oxygen reduction reaction (ORR). The influence of nitrogen-source on the structure and electrocatalytic activity of the nanohorns is studied. Two kinds of N doped carbon nanohorns produced by N2 or melamine as the N-source, respectively, present similar structure. However, dual-doped carbon nanohorns fabricated from different N-sources possess different structures. NB-dual doped carbon nanohorns synthesized by N2 would contain the enormous h-BN, which is chemical-inert for ORR. But using melamine as the N-source would prevent this phenomenon and raise the doping of B atoms into the graphene lattice, which lead to the increased ORR catalytic activity. Different with NB-dual doping, NP-dual doping via N2 would greatly give a rise to the content of N atoms into the materials, and result in the enhanced limited current intensity.Please do not adjust margins Please do not adjust margins As the attractive potential candidate for ORR electrocatalyst, the corresponding tolerance to methanol and stability of NBCNH-m were further investigated. The methanol crossover, The different N-sources used in the preparation would lead to different ways the doped N atoms interact with B or P dopants, and result in the enhanced or declined electrocatalytic activity of dual-doped carbon nanohorns in oxygen reduction reaction.

Carbon Nanohorn-Based Electrocatalysts for Energy Conversion

“…Meanwhile, the determination of the dopant source may play a crucial role in the electrocatalytic performance of the catalyst. As a proof of concept, nitrogen-boron and nitrogen-phosphorous co-doped CNHs (N-B-CNH and N-P-CNH, respectively) were prepared by using two different N-sources for each co-doped material, namely nitrogen and melamine, and boron carbide and triphenylphosphine as B and P sources by the one-step arc discharge method [ 76 ]. It was found that the co-doping of N and P synthesized by nitrogen resulted in higher N-amounts in CNHs, causing high catalytic activity towards ORR.…”

“…On the other hand, N-B dual-doping of CNHs by nitrogen favored the formation of hexagonal boron nitride, which is inert in ORR, resulting in reduced electrocatalytic activity. However, this was not noticed during the incorporation of N-B atoms in CNHs with melamine as N-source, where the synergetic effect among N-C-B due to polarization of adjacent atoms helped in marking the highest electrocatalytic activity overall [ 76 ].…”

Electrochemical Oxygen Reduction Activity of Metal Embedded Nitrogen Doped Carbon Nanostructures Derived from Pyrolysis of Nitrogen-Rich Guanidinium Salt

“…Lotsch et al 11 have reported thermal conversion of guanidine into melamine, widely used as a precursor for preparing M-N-C type electrocatalysts. 12 Furthermore, the intermediate formed during the thermal conversion of guanidine to melamine is reported to be cyanamide -a nitrogen source that has = These authors contributed equally to this work. z E-mail: salex@ariel.ac.il; gedanken@mail.biu.ac.il been employed by Chung et al as precursor for making nitrogen doped carbon micro and nanotubes 13 and carbon nanotube/nanoparticle composite catalysts.…”