scholarly journals One Simple Strategy towards Nitrogen and Oxygen Codoped Carbon Nanotube for Efficient Electrocatalytic Oxygen Reduction and Evolution

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 159 ◽  
Author(s):  
Jing Sun ◽  
Shujin Wang ◽  
Yinghua Wang ◽  
Haibo Li ◽  
Huawei Zhou ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Oxygen Reduction ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Noble Metals ◽  
Oxygen Electrode ◽  
Great Promise ◽  
Simple Strategy ◽  
Electrocatalytic Oxygen Reduction ◽  
Electron Microscopes

The development of advanced electrocatalysts for oxygen reduction and evolution is of paramount significance to fuel cells, water splitting, and metal-air batteries. Heteroatom-doped carbon materials have exhibited great promise because of their excellent electrical conductivity, abundance, and superior durability. Rationally optimizing active sites of doped carbons can remarkably enhance their electrocatalytic performance. In this study, nitrogen and oxygen codoped carbon nanotubes were readily synthesized from the pyrolysis of polydopamine-carbon nanotube hybrids. Different electron microscopes, Raman spectra and X-ray photoelectron spectroscopy (XPS) were employed to survey the morphological and componential properties. The newly-obtained catalyst features high-quality nitrogen and oxygen species, favourable porous structures and excellent electric conductivity, and thus exhibits remarkably bifunctional oxygen electrode activity. This research further helps to advance the knowledge of polydopamine and its potential applications as efficient electrocatalysts to replace noble metals.

scholarly journals Mechanisms of Two-Electron and Four-Electron Electrochemical Oxygen Reduction Reactions at Nitrogen-Doped Reduced Graphene Oxide

2019 ◽  
Author(s):  
Hyo Won Kim ◽  
Vanessa Jane Bukas ◽  
Hun Park ◽  
Sojung Park ◽  
Kyle M. Diederichsen ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Isotope Effects ◽  
Underlying Mechanism ◽  
Reduction Reaction ◽  
Graphene Oxides ◽  
Nitrogen Doped ◽  
General Chemical ◽  
Reduced Graphene

Doped carbon-based systems have been extensively studied over the past decade as active electrocatalysts for both the two-electron (2e-) and four-electron (4e-) oxygen reduction reaction (ORR). However, the mechanisms for ORR are generally poorly understood. Here we report an extensive experimental and first-principles theoretical study of the ORR at nitrogen-doped reduced graphene oxides (NrGO). We synthesize three distinct NrGO catalysts and investigate their chemical and structural properties in detail via X-ray photoelectron spectroscopy, infrared and Raman spectroscopy, high-resolution transmission electron microscopy and thin-film electrical conductivity. ORR experiments include the pH dependences of 2e- versus 4e- ORR selectivity, ORR onset potentials, Tafel slopes and H/D kinetic isotope effects. These experiments show very different ORR behavior for the three catalysts, both in terms of selectivity and the underlying mechanism which proceeds either via coupled proton-electron transfers (CPETs) or non-CPETs. Reasonable structural models developed from DFT rationalize this behavior. The key determinant between CPET vs. non-CPET mechanisms is the electron density at the Fermi level under operating ORR conditions. Regardless of the reaction mechanism or electrolyte pH, however, we identify the ORR active sites as sp2 carbons that are located next to oxide regions. This assignment highlights the importance of oxygen functional groups, while details of (modest) N-doping may still affect the overall catalytic activity, and likely also the selectivity, by modifying the general chemical environment around the active site.

Engineering Active Sites of Gold-Cuprous Oxide Catalysts for Electrocatalytic Oxygen Reduction Reaction

2021 ◽  
Vol 13 (39) ◽  
pp. 46577-46587
Author(s):  
Aiai Zhang ◽  
Jinfang Wu ◽  
Lei Xue ◽  
Caixia Li ◽  
Shanghong Zeng ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Cuprous Oxide ◽  
Active Sites ◽  
Reduction Reaction ◽  
Oxide Catalysts ◽  
Electrocatalytic Oxygen Reduction

scholarly journals Defects on carbons for electrocatalytic oxygen reduction

2018 ◽  
Vol 47 (20) ◽  
pp. 7628-7658 ◽  
Author(s):  
Xuecheng Yan ◽  
Yi Jia ◽  
Xiangdong Yao
Keyword(s):  
Oxygen Reduction ◽  
Active Sites ◽  
Catalysis Mechanism ◽  
Electrocatalytic Oxygen Reduction ◽  
General Defect ◽  
Carbon Based

A general defect promoted catalysis mechanism is established to reveal the active sites of various defective carbon based ORR electrocatalysts.

Enhancement of bio-electrocatalytic oxygen reduction at the composite film of cobalt porphyrin immobilized within the carbon nanotube-supported peroxidase enzyme

2008 ◽  
Vol 53 (5) ◽  
pp. 2408-2415 ◽  
Author(s):  
Barbara Kowalewska ◽  
Magdalena Skunik ◽  
Katarzyna Karnicka ◽  
Krzysztof Miecznikowski ◽  
Malgorzata Chojak ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Composite Film ◽  
Oxygen Reduction ◽  
Cobalt Porphyrin ◽  
Electrocatalytic Oxygen Reduction ◽  
Peroxidase Enzyme

Preparation of monodisperse ferrous nanoparticles embedded in carbon aerogels via in situ solid phase polymerization for electrocatalytic oxygen reduction

Nanoscale ◽  
2020 ◽  
Vol 12 (28) ◽  
pp. 15318-15324
Author(s):  
Wei Hong ◽  
Xin Feng ◽  
Lianqiao Tan ◽  
Aiming Guo ◽  
Bing Lu ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Active Sites ◽  
Solid Phase ◽  
Reduction Reaction ◽  
Carbon Aerogels ◽  
Structured Materials ◽  
Nitrogen Doped ◽  
Electrocatalytic Oxygen Reduction ◽  
Nitrogen Doped Carbon

Core–shell structured materials constructed by using Fe/Fe3C cores and nitrogen doped carbon shells represent a type of promising non-precious oxygen reduction reaction (ORR) catalyst due to well-established active sites at the interface positions.

Sign in / Sign up

Export Citation Format

Share Document