scholarly journals Pd Doped Co3O4 Loaded on Carbon Nanofibers as Highly Efficient Free-Standing Electrocatalyst for Oxygen Reduction and Oxygen Evolution Reactions

2022 ◽  
Vol 9 ◽  
Author(s):  
Ruyue Wang ◽  
Deshuang Hu ◽  
Peng Du ◽  
Xiaodi Weng ◽  
Haolin Tang ◽  
...  
Keyword(s):  
Active Sites ◽  
Carbon Nanofiber ◽  
Ionic Conduction ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Oxygen Electrode ◽  
Free Standing ◽  
Highly Active ◽  
Binder Free

Self-supporting electrodes usually show excellent electrocatalytic performance which does not require coating steps, additional polymer binders, and conductive additives. Rapid in situ growth of highly active ingredient on self-supporting electric conductors is identified as a straight forward path to prepare binder-free and integrated electrodes. Here, Pd-doped Co3O4 loaded on carbon nanofiber materials through electrospinning and heat treatment was efficiently synthesized, and used as a free-standing electrode. Benefiting from its abundant active sites, high surface area and effective ionic conduction capability from three-dimensional (3D) nanofiber framework, Pd-Co3O4@CNF works as bifunctional oxygen electrode and exhibits superior activity and stability superior to commercial catalysts.

scholarly journals Ultrasonic-assisted preparation of highly active Co3O4/MCM-41 adsorbent and its desulfurization performance for low H2S concentration gas

RSC Advances ◽  
2020 ◽  
Vol 10 (50) ◽  
pp. 30214-30222
Author(s):  
Bolong Jiang ◽  
Jiaojing Zhang ◽  
Yanguang Chen ◽  
Hua Song ◽  
Tianzhen Hao ◽  
...  
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
High Surface ◽  
High Surface Area ◽  
Highly Active ◽  
Ultrasonic Assisted ◽  
Sulfur Capacity ◽  
Mcm 41

Co3O4/MCM-41 adsorbent with high surface area and more active sites was successfully prepared by ultrasonic assisted impregnation (UAI) technology and it has been found that the sulfur capacity was improved by 33.2% because of ultrasonication.

Co3S4 Nanosheets on Carbon Cloth as Free-Standing Anode with Improved Pseudocapacitive Storage for High-Performance Li-Ion Batteries

NANO ◽  
2020 ◽  
pp. 2150007
Author(s):  
Jinglong Li ◽  
Xia Wang ◽  
Qiang Li ◽  
Hongsen Li ◽  
Jie Xu ◽  
...  
Keyword(s):  
High Performance ◽  
High Surface ◽  
Specific Capacity ◽  
High Surface Area ◽  
Three Dimensional ◽  
Rate Capability ◽  
Lithium Ion ◽  
Carbon Cloth ◽  
Free Standing ◽  
Storage Behavior

Rationally engineered anode materials with high specific capacities and rate capability are essential for lithium-ion batteries (LIBs). In this paper, a free-standing anode composed of Co3S4 nanosheets arrays and carbon cloth (abbreviated Co3S4@CC) was fabricated for high performance LIBs. The three-dimensional (3D) porous carbon cloth could not only improve the conductivity but also boost Li[Formula: see text] transfer and increase contact area for reactions. Besides, the porous thin Co3S4 nanosheets possessing strong interaction with carbon cloth by formation of C–S bond and high surface area could facilitate the mitigation of volume expansion and reduction of Li[Formula: see text] diffusion distance, coupling with efficient contact with electrolytes during cycling process. As expected, the freestanding Co3S4@CC anode presents pseudocapacitance-dominated storage behavior with a very high specific capacity of 847[Formula: see text]mAh g[Formula: see text] at 250[Formula: see text]mA g[Formula: see text] after 100 cycles and good rate capability for LIBs. This work provides an approach for designing metal sulfides with high capacities and rate capability for LIBs, especially flexible LIBs.

scholarly journals Free-Standing and Heteroatoms-Doped Carbon Nanofiber Networks as a Binder-Free Flexible Electrode for High-Performance Supercapacitors

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1189 ◽  
Author(s):  
Yan ◽  
You ◽  
Liu ◽  
Wang ◽  
Wu
Keyword(s):  
High Performance ◽  
Carbon Nanofiber ◽  
Three Dimensional ◽  
Rate Capability ◽  
Mesoporous Structure ◽  
High Energy ◽  
High Energy Density ◽  
Free Standing ◽  
Electrode Cell ◽  
Binder Free

Flexible and heteroatoms-doped (N, O and P) activated carbon nanofiber networks (ACFNs) have been successfully prepared with a mixture of polyamic acid (PAA) and poly(diaryloxyphosphazene) (PDPP) as a solution through electrospinning, followed by a heat post-treatment. The resultant heteroatoms-doped ACFNs can be used as binder-free electrodes for high-performance flexible supercapacitors (SCs) due to lightweight, three-dimensional open-pore structure and good mechanical strength. Despite its surface area being lower than 130.6 m2·g−1, the heteroatoms-doped ACFNs exhibited a high heteroatoms (N, O and P) content of 17.9%, resulting in a highly specific capacitance of 182 F·g−1 at a current density of 1 A·g−1 in 6 M KOH electrolyte in a two-electrode cell and an excellent rate capability of 74.7% of its initial capacitance from 1 A·g−1 to 10 A·g−1 under the mass loading of 1.5 mg·cm−2. The electrical double-layer (EDL) capacitance and pseudocapacitance can be easily decoupled in the heteroatoms-doped mesoporous ACFNs. SCs device based on heteroatoms-doped ACFNs exhibited a high energy density of 6.3 W·h·kg−1 with a power density of 250 W·kg−1, as well as excellent cycling stability with 88% capacitance retention after 10,000 charge–discharge cycles. The excellent electrochemical performance was attributed to the mesoporous structure of ACFNs and pseudocapacitive heteroatoms.

Metal-organic-framework derived hollow manganese nickel selenide spheres confined with nanosheets on nickel foam for hybrid supercapacitors

2021 ◽  
Author(s):  
Bahareh ameri ◽  
Akbar Mohammadi Zardkhoshoui ◽  
Saied Saeed Hosseiny Davarani
Keyword(s):  
Active Sites ◽  
Nickel Foam ◽  
Metal Organic Framework ◽  
High Surface ◽  
Metal Organic Frameworks ◽  
High Surface Area ◽  
Supercapacitive Performance ◽  
Hybrid Supercapacitors ◽  
Porous Networks ◽  
Metal Organic

Metal-organic frameworks (MOFs) derived nanoarchitectures have special features, such as high surface area (SA), abundant active sites, exclusive porous networks, and remarkable supercapacitive performance when compared to traditional nanoarchitectures. Herein,...

scholarly journals Glucose/Graphene-Based Aerogels for Gas Adsorption and Electric Double Layer Capacitors

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 40 ◽  
Author(s):  
Kang-Kai Liu ◽  
Biao Jin ◽  
Long-Yue Meng
Keyword(s):  
Gas Adsorption ◽  
High Surface ◽  
Aqueous Media ◽  
High Surface Area ◽  
Three Dimensional ◽  
High Specific Capacitance ◽  
Mesopore Size Distribution ◽  
Excellent Electrochemical Performance ◽  
Double Layer Capacitors ◽  
Hydrothermal Reduction

In this study, three-dimensional glucose/graphene-based aerogels (G/GAs) were synthesized using the hydrothermal reduction and CO2 activation method. Graphene oxide (GO) was used as a matrix, and glucose was used as a binder for the orientation of the GO morphology in an aqueous media. We determined that G/GAs exhibited narrow mesopore size distribution, a high surface area (763 m2 g−1), and hierarchical macroporous and mesoporous structures. These features contributed to G/GAs being promising adsorbents for the removal of CO2 (76.5 mg g−1 at 298 K), CH4 (16.8 mg g−1 at 298 K), and H2 (12.1 mg g−1 at 77 K). G/GAs presented excellent electrochemical performance, featuring a high specific capacitance of 305.5 F g−1 at 1 A g−1, and good cyclic stability of 98.5% retention after 10,000 consecutive charge-discharge cycles at 10 A g−1. This study provided an efficient approach for preparing graphene aerogels exhibiting hierarchical porosity for gas adsorption and supercapacitors.

Hierarchical Nano/Micro-structured Surfaces with High Surface Area/Volume Ratios

2021 ◽  
pp. 1-36
Author(s):  
Ketki Lichade ◽  
Yizhou Jiang ◽  
Yayue Pan
Keyword(s):  
Surface Structure ◽  
Surface Area ◽  
Light Trapping ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Structure Design ◽  
Surface Structures ◽  
Structured Surfaces ◽  
Design And Manufacture

Abstract Recently, many studies have investigated additive manufacturing of hierarchical surfaces with high surface area/volume (SA/V) ratios, and their performance has been characterized for applications in next-generation functional devices. Despite recent advances, it remains challenging to design and manufacture high SA/V ratio structures with desired functionalities. In this study, we established the complex correlations among the SA/V ratio, surface structure geometry, functionality, and manufacturability in the Two-Photon Polymerization (TPP) process. Inspired by numerous natural structures, we proposed a 3-level hierarchical structure design along with the mathematical modeling of the SA/V ratio. Geometric and manufacturing constraints were modeled to create well-defined three-dimensional hierarchically structured surfaces with a high accuracy. A process flowchart was developed to design the proposed surface structures to achieve the target functionality, SA/V ratio, and geometric accuracy. Surfaces with varied SA/V ratios and hierarchy levels were designed and printed. The wettability and antireflection properties of the fabricated surfaces were characterized. It was observed that the wetting and antireflection properties of the 3-level design could be easily tailored by adjusting the design parameter settings and hierarchy levels. Furthermore, the proposed surface structure could change a naturally-hydrophilic surface to near-superhydrophobic. Geometrical light trapping effects were enabled and the antireflection property could be significantly enhanced (>80% less reflection) by the proposed hierarchical surface structures. Experimental results implied the great potential of the proposed surface structures for various applications such as microfluidics, optics, energy, and interfaces.

Spidery catalyst for the synthesis of quinazoline-2,4(1H,3H)-diones

2016 ◽  
Vol 6 (5) ◽  
pp. 1435-1441 ◽  
Author(s):  
Seyed Mohsen Sadeghzadeh
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
High Surface ◽  
High Surface Area

In this study, a novel fibrous nanosilica (KCC-1) based nanocatalyst (Au, Pd, and Cu) with a high surface area and easy accessibility of active sites was successfully developed by a facile approach.

Highly active mixed-valent MnOxspheres constructed by nanocrystals as efficient catalysts for long-cycle Li–O2batteries

2016 ◽  
Vol 4 (43) ◽  
pp. 17129-17137 ◽  
Author(s):  
Sanpei Zhang ◽  
Zhaoyin Wen ◽  
Yang Lu ◽  
Xiangwei Wu ◽  
Jianhua Yang
Keyword(s):  
Surface Area ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Long Cycle ◽  
Highly Active

We demonstrate a low-cost and facile strategy to synthesize mixed-valent MnOxspheres constructed from nanocrystals (~5 nm), containing MnII, MnIII, and MnIVspecies. Such highly active mixed-valent MnOxspheres with high surface area greatly improve the performance of Li–O2batteries.

scholarly journals Catalytic Cracking of n-Hexadecane Using Carbon Nanostructures/Nano-Zeolite-Y Composite Catalyst

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1385
Author(s):  
Botagoz Zhuman ◽  
Shaheen Fatima Anis ◽  
Saepurahman ◽  
Gnanapragasam Singravel ◽  
Raed Hashaikeh
Keyword(s):  
Surface Area ◽  
Catalytic Cracking ◽  
Carbon Nanostructures ◽  
Active Sites ◽  
Zeolite Y ◽  
High Surface ◽  
High Surface Area ◽  
Composite Catalyst ◽  
Homogeneous Distribution ◽  
Binding Material

Zeolite-based catalysts are usually utilized in the form of a composite with binders, such as alumina, silica, clay, and others. However, these binders are usually known to block the accessibility of the active sites in zeolites, leading to a decreased effective surface area and agglomeration of zeolite particles. The aim of this work is to utilize carbon nanostructures (CNS) as a binding material for nano-zeolite-Y particles. The unique properties of CNS, such as its high surface area, thermal stability, and flexibility of its fibrous structure, makes it a promising material to hold and bind the nano-zeolite particles, yet with a contemporaneous accessibility of the reactants to the porous zeolite structure. In the current study, a nano-zeolite-Y/CNS composite catalyst was fabricated through a ball milling approach. The catalyst possesses a high surface area of 834 m2/g, which is significantly higher than the conventional commercial cracking catalysts. Using CNS as a binding material provided homogeneous distribution of the zeolite nanoparticles with high accessibility to the active sites and good mechanical stability. In addition, CNS was found to be an effective binding material for nano-zeolite particles, solving their major drawback of agglomeration. The nano-zeolite-Y/CNS composite showed 80% conversion for hexadecane catalytic cracking into valuable olefins and hydrogen gas, which was 14% higher compared to that of pure nano-zeolite-Y particles.

scholarly journals Green and facile synthesis of cerium doped Ni3Fe electrocatalyst for efficient oxygen evolution reaction

2020 ◽  
Vol 34 (2) ◽  
pp. 353-363
Author(s):  
F. Kanwal ◽  
A. Batool ◽  
R. Akbar ◽  
S. Asim ◽  
M. Saleem
Keyword(s):  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Large Scale ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Alkaline Electrolyte ◽  
Hydrogen Electrode ◽  
Molar Ratios

Electrochemical water splitting is the most promising pathway to produce high-purity hydrogen to alleviate global energy crisis. This reaction demands inexpensive, efficient and robust electrocatalyst for its commercial use. Herein, we demonstrate an effective, facile and scalable method for the synthesis of cerium doped Ni3Fe nanostructures as an electrocatalyst for oxygen evolution reaction (OER) by following simple chemical bath deposition route. The different molar ratios (3, 6 and 12 mM) of cerium in the chemical bath were used to study its effect on the structural and the electrochemical properties of the Ni3Fe nanostructured films. Doping of cerium contents induced variations in the morphology of deposited Ni3Fe nanostructures. The optimized electrocatalyst Ni3Fe/Ce-6 yielded high surface area catalyst nanosheets uniformly deposited on three-dimensional conductive scaffold to ensure increase in the exposure of doped Ni3Fe catalytic sites with high electrical conductivity. As a result, this earth-abundant electrocatalyst affords high OER performance with a small overpotential of 310 mV versus reversible hydrogen electrode (RHE) at 10 mA cm-2 and retains good stability up to ~ 10 h in alkaline electrolyte. This scalable strategy has great potential in future advancement of efficient and low-cost electrocatalysts for their large-scale application in energy conversion systems.                     KEY WORDS: Oxygen evolution, Electrocatalyst, Ni3Fe nanostructures, Cerium, Alkaline electrolyte   Bull. Chem. Soc. Ethiop. 2020, 34(2), 353-363 DOI: https://dx.doi.org/10.4314/bcse.v34i2.12

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