Carbon nanocapsules as an electrocatalyst support for the oxygen reduction reaction in alkaline electrolyte

Abstract

Carbon Nanocapsules (CNCs) were investigated for their electrocatalytic performances for the oxygen reduction reaction in alkaline electrolyte. With an average diameter of 10-30 nm, the CNCs are composed of graphene layers encapsulating a hollow core. A gas diffusion electrode (GDE) made of CNCs revealed a much enhanced i-V polarization response than that of Vulcan XC72. However, its performance was moderately lower than that of Black Pearls 2000. In addition, the CNCs were impregnated with nanoparticles of Ag, MnO x and CoO x . The i-V and galvanostatic results of the catalyzed CNCs indicated significant improvements over that of noncatalyzed CNCs. For example, a Ag-CNC derived GDE was capable of delivering 1.03 and 0.88 V at current densities of 100 and 200 mA cm -2 , respectively. Our study offers direct evidence that the CNCs not only exhibit unique electrocatalytic abilities but also function superbly as an electrocatalyst support.

Synthesis of highly nitrogen-doped hollow carbon nanoparticles and their excellent electrocatalytic properties in dye-sensitized solar cells

“…They are mainly prepared by the template-duplicate technique. In contrast to conventional porous carbon materials, such as activated carbon, HCNPs exhibit uniform meso-structured and/or hierarchical pores, and display the intrinsic characteristics of carbon nanostructures, which endow them with wide potential applications in lithium ion batteries, 1,2 fuel cells, 3,4 energy storage, 2 catalysis, 5 and drug delivery. 6 In most of their applications, the performance of HCNPs depends greatly not only on their morphological, textural, and structural characteristics, but also on their surface chemistry and electronic properties.…”

Synthesis of graphitic mesoporous carbons with high surface areas and their applications in direct methanol fuel cells

“…The electrocatalysts supported on graphitic carbons, such as carbon nanotubes [9][10][11], carbon nanofibers [12,13], ordered hierarchical nanostructured carbons [14], carbon nanocapsule [15,16], carbon nanocages [17], ordered mesoporous carbons [18][19][20], and carbon nanocoils [21], showed good activity and stability whether in acidic solutions or in real fuel cell working conditions. Various conventional synthesis methods, including arc discharge, laser evaporation, and chemical vapor deposition, have been used to prepare graphitic carbons [22][23][24].…”

Controlled Synthesis of Silver Particles Supported on Carbon Nanocapsules for Oxygen Reduction Reaction in Alkaline Electrolyte

“…Recently, Yu and Yam reported a controlled synthetic approach preparing monodisperse silver nanotubes in water [3]. Previously, we synthesized various catalysts supported on carbon nanocapsules (CNCs) and studied their oxygen reduction capabilities [4]. The objective for this work is to carry out detailed electrochemical analysis on Ag-CNCs, and in particular, study the size and shape effects of Ag particles on the resulting oxygen reduction abilities in alkaline electrolyte.…”