Conductive bimetal organic framework nanorods decorated with highly dispersed Co3O4 nanoparticles as bi-functional electrocatalyst

2021 ◽  
Author(s):  
Yaxin Duan ◽  
Haitao Liu ◽  
Huabing Zhang ◽  
Shaojie Ke ◽  
Shuaize Wang ◽  
...  
Keyword(s):  
Electrocatalytic Activity ◽  
Electronic Conductivity ◽  
Reduction Reaction ◽  
Alkaline Electrolyte ◽  
Co3o4 Nanoparticles ◽  
Cobalt Ions ◽  
Design And Synthesis ◽  
Half Wave ◽  
Highly Dispersed ◽  
Organic Framework

Abstract The poor electronic conductivity and low intrinsic electrocatalytic activity of metal organic frameworks (MOFs) greatly limit their direct application in electrocatalytic reactions. Herein, we report a conductive two-dimensional π–d conjugated Ni and Co bimetal organic framework (MOF)——NiCo-(2,3,6,7,10,11-hexaiminotriphenylene) (NiCo-HITP) nanorods decorated with highly dispersed Co3O4 nanoparticles (NPs) as a promising bi-functional electrocatalyst towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) through an effective and facile strategy by modifying the rod-shaped Ni3(HITP)2 crystals using cobalt ions. The triggered electrocatalytic activity of the resulting MOF-based materials was achieved by increasing the electrical conductivity (7.23 S cm-1) originated from Ni3(HITP)2 substrate and also by creating the cooperative catalysis sites of Co-Nx and Co3O4 NPs. Optimized syntheses show a promising ORR activity with a high half-wave potential (0.77 V) and also a significantly improved OER activity compared with pure Ni3(HITP)2 in alkaline electrolyte. Furthermore, a rechargeable Zn–air battery using the as-prepared material as air-cathode also shows a high power density (143.1 mW cm-2) –even comparable to a commercial Pt/C-RuO2-based battery. This methodology offers a new prospect in the design and synthesis of non-carbonized MOF bi-functional electrocatalysts for efficient catalysis towards ORR and OER.

Synthesis of an ε-MnO2/metal–organic-framework composite and its electrocatalysis towards oxygen reduction reaction in an alkaline electrolyte

2015 ◽  
Vol 3 (31) ◽  
pp. 16168-16176 ◽  
Author(s):  
Hao Wang ◽  
Fengxiang Yin ◽  
Biaohua Chen ◽  
Guoru Li
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Metal Organic Framework ◽  
Reduction Reaction ◽  
Alkaline Electrolyte ◽  
Metal Organic ◽  
Organic Framework

An ε-MnO2/metal–organic-framework (Fe) (i.e., ε-MnO2/MOF(Fe)) composite was synthesised by integrating ε-MnO2 and a MOF(Fe) support.

scholarly journals Synthesis and electrocatalytic activity towards oxygen reduction reaction of gold-nanostars

2018 ◽  
Vol 18 (44) ◽  
pp. 36-40
Author(s):  
Oyunbileg G ◽  
Batnyagt G ◽  
Enkhsaruul B ◽  
T Takeguchi
Keyword(s):  
Electron Microscope ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Electrocatalytic Activity ◽  
Electrical Energy ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Alkaline Electrolyte ◽  
Study Results

The oxygen reduction reaction (ORR) is a characteristic reaction which determines the performance of fuel cells which convert a chemical energy into an electrical energy. Aims of this study are to synthesize Au-based nanostars (AuNSs) and determine their preliminary electro-catalytic activities towards ORR by a rotating-disk electrode method in alkaline electrolyte. The images obtained from a scanning electron microscope (SEM) and a transmission electron microscope (TEM) analyses confirm the formation of the star-shaped nanoparticles. Among the investigated nanostar catalysts, an AuNS5 with smaller size and a few branches showed the higher electrocatalytic activity towards ORR than other catalysts with a bigger size. In addition, the electron numbers transferred for all the catalysts are approximately two. The present study results infer that the size of the Au-based nanostars may influence greatly on their catalytic activity. The present study results show that the further improvement is needed for Au-based nanostar catalysts towards the ORR reaction.

Electrochemical behavior of a number of bispyridyl-substituted porphyrins and their electrocatalytic activity in molecular oxygen reduction reaction

2016 ◽  
Vol 20 (05) ◽  
pp. 615-623 ◽  
Author(s):  
Minh N. Do ◽  
Nadezhda M. Berezina ◽  
Mikhail I. Bazanov ◽  
Sabir S. Gyseinov ◽  
Mikhail M. Berezin ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Molecular Oxygen ◽  
Electrocatalytic Activity ◽  
Reduction Reaction ◽  
Central Metal ◽  
Axial Ligands ◽  
Active Layers ◽  
Half Wave ◽  
Electrochemical Parameters

The investigation of electrochemical properties of active layers containing 5,15-bis(pyrid-3-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphine, [5,15-bis(pyrid-3-yl)-3,7,13,17-tetramethyl-2,8,12, 18-tetraethylporphinato]cobalt(II), bispyridine[5,15-bis(pyrid-3-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphinato]cobalt(III), [5,15-bis(pyrid-4-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphinato]cobalt(II) and bispyridine[5,15-bis(pyrid-4-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphinato]cobalt(III) in 0.1 M KOH aqueous solution has been carried out by cyclic voltammetry. The potential ranges of redox processes related to the transformation of the porphyrin macrocycle, pyridyl substituents and central metal have been established. The electrochemical parameters of oxygen electroreduction reaction (the half-wave potential — E[Formula: see text](O[Formula: see text]), the maximum potential — E[Formula: see text](O[Formula: see text]), the current density — j, the activation energy — Eact) have been determined. It was shown that all porphyrins exhibit the catalytic activity. The electroreduction process of oxygen on electrode with the porphyrin-ligand occurs via 2-electron mechanism to give hydrogen peroxide ion HO2-, and on ones with the cobalt porphyrins — via parallel-sequential pathway including 2-electron and 4-electron processes to give HO2-, OH-. The presence of pyridine axial ligands in Co-complexes leads to a significant increase of the electrocatalytic activity in molecular oxygen reduction reaction.

scholarly journals Effect of Co3O4 Nanoparticles on Improving Catalytic Behavior of Pd/Co3O4@MWCNT Composites for Cathodes in Direct Urea Fuel Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1017
Author(s):  
Nguyen-Huu-Hung Tuyen ◽  
Hyun-Gil Kim ◽  
Young-Soo Yoon
Keyword(s):  
Fuel Cells ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Electrocatalytic Activity ◽  
Hydrothermal Process ◽  
Pd Nanoparticles ◽  
Reduction Reaction ◽  
Co3o4 Nanoparticles ◽  
Cathode Catalyst ◽  
Multi Walled Carbon Nanotubes

Direct urea fuel cells (DUFCs) have recently drawn increased attention as sustainable power generation devices because of their considerable advantages. Nonetheless, the kinetics of the oxidation-reduction reaction, particularly the electrochemical oxidation and oxygen reduction reaction (ORR), in direct urea fuel cells are slow and hence considered to be inefficient. To overcome these disadvantages in DUFCs, Pd nanoparticles loaded onto Co3O4 supported by multi-walled carbon nanotubes (Pd/Co3O4@MWCNT) were employed as a promising cathode catalyst for enhancing the electrocatalytic activity and oxygen reduction reaction at the cathode in DUFCs. Co3O4@MWCNT and Pd/Co3O4@MWCNT were synthesized via a facile two-step hydrothermal process. A Pd/MWCNT catalyst was also prepared and evaluated to study the effect of Co3O4 on the performance of the Pd/Co3O4@MWCNT catalyst. A current density of 13.963 mA cm−2 and a maximum power density of 2.792 mW cm−2 at 20 °C were obtained. Pd/Co3O4@MWCNT is a prospectively effective cathode catalyst for DUFCs. The dilution of Pd with non-precious metal oxides in adequate amounts is economically conducive to highly practical catalysts with promising electrocatalytic activity in fuel cell applications.

scholarly journals Recent Advances in Isolated Single-Atom Catalysts for Zinc Air Batteries: A Focus Review

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1402 ◽  
Author(s):  
Weimin Zhang ◽  
Yuqing Liu ◽  
Lipeng Zhang ◽  
Jun Chen
Keyword(s):  
Electrocatalytic Activity ◽  
High Performance ◽  
Rational Design ◽  
High Energy ◽  
Reduction Reaction ◽  
High Energy Density ◽  
Single Atom ◽  
Design And Synthesis ◽  
Dual Metal ◽  
Zinc Air Batteries

Recently, zinc–air batteries (ZABs) have been receiving attention due to their theoretically high energy density, excellent safety, and the abundance of zinc resources. Typically, the performance of the zinc air batteries is determined by two catalytic reactions on the cathode—the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Therefore, intensive effort has been devoted to explore high performance electrocatalysts with desired morphology, size, and composition. Among them, single-atom catalysts (SACs) have emerged as attractive and unique systems because of their high electrocatalytic activity, good durability, and 100% active atom utilization. In this review, we mainly focus on the advance application of SACs in zinc air batteries in recent years. Firstly, SACs are briefly compared with catalysts in other scales (i.e., micro- and nano-materials). A main emphasis is then focused on synthesis and electrocatalytic activity as well as the underlying mechanisms for mono- and dual-metal-based SACs in zinc air batteries catalysis. Finally, a prospect is provided that is expected to guide the rational design and synthesis of SACs for zinc air batteries.

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