Growth of binder free mesoporous 3D-CuCo2O4 electrocatalysts with high activity and stability for electro-oxidation of methanol (original) (raw)
Related papers
ChemCatChem, 2019
Transition metal oxides have attracted attention as promising electrode materials for energy storage and conversion devices with high electrochemical activity and stability. In this study, a simple and cost‐effective solvothermal synthesis of rectangular 3D CuCo2O4 hollow tubes have been developed for methanol electro‐oxidation application. Electrochemical analysis shows that CuCo2O4 hollow tubes exhibit superior electrochemical performance in terms of current density and cycling stability, with 75 mA cm−2 and 90 % retention rate after 1000 cycles, respectively. The high electrochemical performances are mainly due to the morphological structure of CuCo2O4 hollow tubes, which possess high surface area and porosity, resulting to a faster electron‐ion transfer, enhanced reactivity and stability. Given that the synthesis of CuCo2O4 hollow tubes involve a facile and cost‐effective technique, the present approach, thus, opens a new era to novel materials for large‐scale processes in diffe...
Nanomaterials
Although direct methanol fuel cells (DMFCs) have been spotlighted in the past decade, their commercialization has been hampered by the poor efficiency of the methanol oxidation reaction (MOR) due to the unsatisfactory performance of currently available electrocatalysts. Herein, we developed a binder-free, copper-based, self-supported electrode consisting of a heterostructure of Cu3P and mixed copper oxides, i.e., cuprous–cupric oxide (Cu-O), as a high-performance catalyst for the electro-oxidation of methanol. We synthesized a self-supported electrode composed of Cu-O|Cu3P using a two-furnace atmospheric pressure–chemical vapor deposition (AP-CVD) process. High-resolution transmission electron microscopy analysis revealed the formation of 3D nanocrystals with defects and pores. Cu-O|Cu3P outperformed the MOR activity of individual Cu3P and Cu-O owing to the synergistic interaction between them. Cu3P|Cu-O exhibited a highest anodic current density of 232.5 mAcm−2 at the low potential...
Bi‐Co‐Cu Metal Oxide Foam as Significant Electrocatalyst for Methanol Electrooxidation
ChemistrySelect, 2020
Transition metals and metal oxides are carrying out vibrant role in electrooxidation of methanol. Unfortunately, the unclear cognition of methanol oxidation reaction (MOR) mechanism hampers the development of high performance electrocatalysts. Thus, in this report, a fascinating MOR mechanism has been studied using CoCuBi oxide foam structure, where the (220) plane of CoCuBi oxides are playing an exciting role in an unprecedented mechanism. Interestingly, the (220) plane belongs to the families of plane, where transition metal oxides prefer Eley-Rideal (ER) mechanism with concomitant reduction in the poisoning effect due to CO. The synergetic effect of these planes triggers the excellent current density of 118 mA/ cm 2 with 50% retention of activity even after 10 h stability test. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) studies revealed different oxidation states of metal ions indicating formation of mixed oxides along with different phase formation in CoCuBi foam structure. More excitingly, CoCuBi nanocomposites show remarkable electrochemical methanol oxidation to form specific product such as formate, which is strongly confirmed by proton NMR spectroscopy.
Crystals, 2021
Methanol electrochemical oxidation in a direct methanol fuel cell (DMFC) is considered to be an efficient pathway for generating renewable energy with low pollutant emissions. NiO−CuO and Ni0.95Cr0.05O2+δ thin films were synthesized using a simple dip-coating method and tested for the electro-oxidation of methanol. These synthesized electrocatalysts were characterized by X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy. Different electrochemical techniques were used to investigate the catalytic activity of these prepared electrocatalysts for methanol oxidation, including linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA). In the presence of 0.3 M methanol, the current densities of NiO−CuO and Ni0.95Cr0.05O2+δ thin films were found to be 12.2 mA·cm−2 and 6.5 mA·cm−2, respectively. The enhanced catalyt...
ACS Sustainable Chemistry & Engineering, 2018
Transition metals have been emerged as highly active catalysts for methanol oxidation reaction. 12 The development of low density metallic foams is exceedingly intriguing for various 13 applications. Here we report a systematic design of three dimensional (3D) porous 14 nanocomposites (foam) of transition metals like Cu and Ni with reduced graphite oxide (Cu-15 Ni@rGO) using simple self-propagation combustion method, where Cu-Ni foam structures are 16 wrapped around reduced graphite oxide. The field emission scanning electron microscopy 17 (FESEM) and transmission electron microscopy (TEM) show nanoporous structural morphology. 18 X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) show presence of different 19 oxidation states of metal ions and phase formation respectively. The electrochemical studies of 20 Cu-Ni@rGO nanocomposites exhibit interesting methanol electrooxidation properties with 21 exciting current density of 280 mA/cm 2 , which further retain 95% of their activity even after 600 22 s. In addition, these, Cu-Ni@rGO structures also reveal negligible poisoning effects during 23 methanol electrooxidation. More interestingly, Cu-Ni@rGO nanocomposites show remarkable 24 electrochemical CO oxidation to form CO 2 and the evidences support the Eley-Rideal 25 mechanism of CO oxidation, where presence of oxygen does not affect the oxidation process. 26
Nanomaterials
In this work a novel bimetallic nickel oxide/copper oxide metal–organic framework (NiO/CuO MOF) has been developed by using two linkers: Benzene Dicarboxylic acid (BDC) and Pyrazine. The composites of NiO/CuO MOF with different amounts of reduced graphene oxide (rGO) were synthesized through a hydrothermal method and subsequently characterized by multiple significant techniques like XRD, SEM, EDX, FTIR and Raman IR for an investigation of their structural and morphological properties. The prepared series of material was later employed for electrochemical oxidation of methanol, tested by cyclic voltammetry (CV) in basic medium on a modified glassy carbon electrode (GCE). The electrochemical response depicts that increasing concentration of rGO enhances the electrocatalytic activity of the catalyst for methanol oxidation reaction (MOR). The catalyzed oxidation reaction of methanol by NiO/CuO MOF and rGO-NiO/CuO MOF composites give a superlative current density of 437. 28 mA/cm2 at 0.9...
Electrochimica Acta, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Ternary spinel CuCo 2 O 4 nanostructure clenches great potential as high-performance electrode material for next-generation energy storage systems because of its higher electrical conductivity and electrochemical activity. Carbon free and binder free 3D flower-like CuCo 2 O 4 structure are grown on nickel foam (NF) via a facile hydrothermal synthesis method followed by annealing. The obtained CuCo 2 O 4 /NF is directly used as electrode for lithium ion batteries (LIBs) and supercapacitors (SCs) application. The electrochemical study of 3D flower-like CuCo 2 O 4 as an electrode for LIB and SC shows highly mesoporous unique architecture plays important role in achieving high capacity/capacitance with superior cycle life. The high surface area and mesoporous nature not only offer sufficient reaction sites, but also can accelerate the liquid electrolyte to penetrate electrode and the ions to reach the reacting sites. In outcome, it exhibits highest capacity of 1160 mA h g −1 after 200 cycles when used as an anode for LIB and specific capacitance of 1002 F g −1 after 3000 cycles. The superior electrochemical of synthesized material is attributed to direct contact of electrode active material with good intrinsic electrical conductivity to the underneath conductive NF substrate builds up an express path for fast ion and electron transfer.
Electrochimica Acta, 2024
Tailoring a reduced graphene oxide-Cu-Cu 2 O (rGO-Cu-Cu 2 O) as a three-dimensional (3D) integrated catalytic system via an in-situ potential-controlled electrodeposition approach is a feasible pathway to boost methanol oxidation reaction (MOR) for direct methanol fuel cell. The enhancement in catalytic functionality and performances is due to the synergistic interaction between the in-situ electroreduced graphene oxide (rGO) and copper metal ions over it. The sequential and synergistic effect of the co-deposition potential, optimized time, and probable corrosion-promotion effect (formation of a galvanic cell between rGO and copper due to entrapped dissolved oxygen) is believed to be responsible for the structural growth of as-developed 3D catalytic systems. The MOR results suggest that the composite material deposited at the higher cathodic deposition potential (-1.2 V vs SCE), i.e., rGO-Cu (c) featured the remarkable lowest onset oxidation potential (i.e., +0.37 V), peak potential (i.e., +0.73 V), peak current density (135.76 mAcm − 2), potentiostatic durability at +0.6 V after 3.5 h (~65.85 mAcm − 2) and outstanding cyclic stability (~97.7 % current retention after 500 cycles), which is superior to the other modified composite electrodes. The enhanced performances are due to the effective dissociative adsorption of methanol from the available active catalytic site's and the presence of hydroxyl groups which has probably improved the oxidation of adsorbed intermediates from the surface. Further, Fouriertransform infrared (FT-IR) experiments revealed that formate as an active intermediate is being generated on all three rGO-Cu-Cu 2 O modified electrodes and follows the non-CO reaction pathway for direct oxidation of methanol.