Promotion of Nitrogen Reserve and Electronic Regulation in Bamboo-like Carbon Tubules by Cobalt Nanoparticles for Highly Efficient ORR

Abstract

N-doped carbon materials are the promising oxygen reduction reaction (ORR) electrocatalyst for many energy systems such as fuel cells and metal–air batteries. Here we report a facile method to regulate electronic structures of bamboo-like carbon tubules dually by rich N-doping and Co particles decoration via pyrolysis of HNO3-treated melamine with Co(OH)2 nanoparticles in an Ar environment (Co-NC-T). XRD, XAFS, and Raman spectra indicate the abundant decoration of metal Co rather than CoOx, and XPS spectra confirm the rich N-doping (7.6%) and abundant Co-NC sites in Co-NC-700, which shows superior ORR activities in 0.1 M KOH with the onset potential of 0.95 V, half-wave potential of 0.90 V, good stability, and methanol tolerance ability. The deformation charge density and adsorption energies (DFT) indicate the dual electronic regulations by N-doping and metal Co can significantly accelerate O2 adsorption and improve conductivity, which are beneficial for ORR performance of carbon materials. This work provides a facile method to obtain highly active carbon materials via the electronic regulation for efficient catalysis.