Effect of Different Iron Sources on In-Situ Growth of Zeolitic Imidazolate Frameworks-8: For Efficient Oxygen Reduction Electrocatalysts

2021 ◽  
Vol 21 (10) ◽  
pp. 5319-5328
Author(s):  
Sha-Sha Luo ◽  
Yu-Meng Ma ◽  
Peng-Wei Li ◽  
Ming-Hua Tian ◽  
Qiao-Xia Li
Keyword(s):  
Catalytic Activity ◽  
High Temperature ◽  
Oxygen Reduction ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Precious Metals ◽  
High Catalytic Activity ◽  
Zeolitic Imidazolate Frameworks ◽  
Wide Range

Transition metal and nitrogen co-doped carbon-based catalysts (TM-N-C) have become the most promising catalysts for Pt/C due to their wide range of sources, low cost, high catalytic activity, excellent stability and strong resistance to poisoning, especially Fe–N–C metal-organic frameworks (MOFs), which are some of the most promising precursors for the preparation of Fe–N–C catalysts due to their inherent properties, such as their highly ordered three-dimensional framework structure, controlled porosity, and tuneable chemistry. Based on these, in this paper, different iron sources were added to synthesis a sort of zeolitic imidazole frameworks (ZIF-8). Then the imidazole salt in ZIF-8 was rearranged into high N-doped carbon by high-temperature pyrolysis to prepare the Fe–N–C catalyst. We studied the physical characteristics of the catalysts by different iron sources and their effects on the catalytic properties of the oxygen reduction reaction (ORR). From the point of morphology, various iron sources have a positive influence on maintaining the morphology of ZIF-8 polyhedron. Fe–N/C–Fe(NO3)3 has the same anion as zinc nitrate, and can maintain a polyhedral morphology after high-temperature calcination. It had the highest ORR catalytic activity compared to the other four catalyst materials, which proved that there is a certain relationship between morphology and performance. This paper will provide a useful reference and new models for the development of high-performance ORR catalysts without precious metals.

A cobalt–nitrogen complex on N-doped three-dimensional graphene framework as a highly efficient electrocatalyst for oxygen reduction reaction

Nanoscale ◽  
2014 ◽  
Vol 6 (24) ◽  
pp. 15066-15072 ◽  
Author(s):  
Yuanyuan Jiang ◽  
Yizhong Lu ◽  
Xiaodan Wang ◽  
Yu Bao ◽  
Wei Chen ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Precious Metal ◽  
High Performance ◽  
Raw Materials ◽  
Low Cost ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
Highly Efficient ◽  
Doped Graphene

Effective preparation of a high-performance non-precious metal oxygen reduction electrocatalyst (a Co–N complex on 3D N-doped graphene) by a facile method from low-cost raw materials.

scholarly journals Low-Cost Open-Source Device to Measure Maximal Inspiratory and Expiratory Pressures

2021 ◽  
Vol 12 ◽  
Author(s):  
Claudia Aymerich ◽  
Miguel Rodríguez-Lázaro ◽  
Gorka Solana ◽  
Ramon Farré ◽  
Jorge Otero
Keyword(s):  
Open Source ◽  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
Three Dimensional ◽  
Technical Information ◽  
Whole Body ◽  
Measurement Tool ◽  
Measuring Device ◽  
Wide Range

The measurement of maximal inspiratory (MIP) and maximal expiratory (MEP) pressures is a widely used technique to non-invasively evaluate respiratory muscle strength in clinical practice. The commercial devices that perform this test range from whole body plethysmographs to portable spirometers, both expensive and include a wide range of other respiratory tests. Given that a portable, low-cost, and specific option for MIP and MEP measuring device is not currently available in the market. A high-performance and easy-to-build prototype has been developed and the detailed technical information to easily reproduce it is freely released. A novel device is based on an Arduino microcontroller with a digital display, an integrated pressure transducer, and three-dimensional (3D) printed enclosure (total retail cost €80). The validation of the device was performed by comparison with a laboratory reference setting, and results showed accuracy within ±1%. As the device design is available according to the open-source hardware approach, measuring MIP/MEP can greatly facilitate easily available point-of-care devices for the monitoring of patients and, most important, for making this lung function measurement tool affordable to users in low- and middle-income countries.

scholarly journals Nanosheets with High-Performance Electrochemical Oxygen Reduction Reaction Revived from Green Walnut Peel

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 328
Author(s):  
Yifei Zhou ◽  
Lei Yan ◽  
Junhua Hou
Keyword(s):  
Oxygen Reduction ◽  
High Performance ◽  
Hot Spot ◽  
Hydrothermal Process ◽  
Reduction Reaction ◽  
Alkaline Electrolyte ◽  
High Catalytic Activity ◽  
Metal Free ◽  
Thin Carbon ◽  
Wide Range

The synthesis of metal-free carbon-based electrocatalysts for oxygen reduction reactions (ORR) to replace conventional Pt-based catalysts has become a hot spot in current research. This work proposes an activation-assisted carbonization strategy, to manufacture N-doped ultra-thin carbon nanosheets (GWS180M800) with high catalytic activity, namely, melamine is used as an accelerator/nitrogen source, and walnut green peels biological waste as a carbon source. The melamine acts as a nitrogen donor in the hydrothermal process, effectively enhancing the nitrogen doping rate. The content of pyridine nitrogen groups accounts for up to 48.5% of the total nitrogen content. Electrochemical tests show that the GWS180M800 has excellent ORR electrocatalytic activity and stability, and makes a quasi-four-electron ORR pathway clear in the alkaline electrolyte. The initial potential and half slope potential are as high as 1.01 and 0.82 V vs. RHE, respectively. The GWS180M800 catalyst has a better ability to avoid methanol cross poisoning than Pt/C has. Compared with 20 wt% Pt/C, GWS180M800 has improved methanol tolerance and stability. It is a metal-free biochar ORR catalyst with great development potential and application prospects. This result provides a new space for the preparation of valuable porous nano-carbon materials based on carbonaceous solid waste and provides new ideas for catalyzing a wide range of electrochemical reactions in the future.

Study of the Preparation and Property of Oxygen Reduction Electrode Based on Polyaniline or Polypyrrole

2013 ◽  
Vol 320 ◽  
pp. 639-643 ◽  
Author(s):  
Qing Hao Yang ◽  
Tian Zhu Huang
Keyword(s):  
Catalytic Activity ◽  
Oxygen Reduction ◽  
Noble Metal ◽  
Influential Factor ◽  
Metal Catalyst ◽  
High Catalytic Activity ◽  
Noble Metal Catalyst ◽  
Binding Forms ◽  
Wide Range ◽  
Physical And Chemical

Polyaniline (PANI) and polypyrrole (PPy) is developed rapidly with special physical and chemical performance. According to high catalytic activity, polyaniline is applied in a wide range of electrocatalysis area, especially for oxygen reduction. In this paper, electrochemical prepared polyaniline was used as catalyst as well as the loading of noble metal catalyst for manufacturing oxygen reduction electrode. Then the influence of carrier, noble metal and their binding forms to the ability of oxygen reduction were investigated by cyclic voltammeter. The result shows that PANI carrier was the most influential factor for oxygen reduction; for single noble metal catalyst, Pt shows bigger catalytic activity than Ag. And the best catalytic activity was optimized at dual deposited catalyst as Ag, Pt mass ratio to 23:100. Further more; compared to glassy carbon, graphite is much better for electrode basement.

Single-atom-sized Ni–N4 sites anchored in three-dimensional hierarchical carbon nanostructures for the oxygen reduction reaction

2020 ◽  
Vol 8 (30) ◽  
pp. 15012-15022
Author(s):  
Zhewei Cai ◽  
Pan Du ◽  
Wenhui Liang ◽  
Hui Zhang ◽  
Ping Wu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Carbon Nanostructures ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
Single Atom ◽  
High Catalytic Activity ◽  
Hierarchical Carbon

Single-atom-sized Ni–N4 sites embedded in three-dimensional and hierarchically structured carbon exhibit a high catalytic activity for the ORR.

Scalable synthesis of bi-functional high-performance carbon nanotube sponge catalysts and electrodes with optimum C–N–Fe coordination for oxygen reduction reaction

2015 ◽  
Vol 8 (6) ◽  
pp. 1799-1807 ◽  
Author(s):  
Gang Yang ◽  
Woongchul Choi ◽  
Xiong Pu ◽  
Choongho Yu
Keyword(s):  
Catalytic Activity ◽  
Carbon Nanotube ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
High Performance ◽  
Synthesis Method ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
Scalable Synthesis

Three-dimensional N/Fe-containing carbon nanotube sponges showing striking improvements in catalytic activity and stability were grown using a facile/scalable synthesis method.

Design and Synthesis of a High Performance Coating

2019 ◽  
Author(s):  
Swarn Jha ◽  
Yan Chen ◽  
Rick Wang ◽  
Mohamed Gharib ◽  
Hong Liang
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Structural Integrity ◽  
Low Cost ◽  
Surface Characteristics ◽  
Design And Synthesis ◽  
Main Challenge ◽  
Lubrication Performance ◽  
Wide Range ◽  
High Performance Coating

Abstract High performance coatings are needed for downhole drilling applications. The main challenge in developing such coatings is to impart desirable surface characteristics such as low friction, high wear and corrosion resistance, while retaining structural integrity and consistency. Most coatings do not sustain the conditions in harsh environments resulting in failure and safety hazards. In this research, we designed high temperature coatings with integration of components that display wear resistance. After synthesis, they exhibited promising lubrication performance. Specifically, a simple and low-cost method was developed that can process the coating consisting high-temperature ceramics such as BN, SiC. Hybridizing graphite and α-zirconium phosphate as friction modifiers ideal for use with metals, alloys and ceramics, this coating is durable in a wide range of temperatures. Experimental results showed that the friction coefficient obtained for our coating was 0.17 as against the 0.50 value obtained for steel on steel sliding contact. In this work, we detail about the composition, microstructure, and tribological evaluation of the coatings tailored for drilling applications.

scholarly journals Fabrication of Non-precious Vanadium Tungsten Nanocomposite for Enhanced Electrocatalytic Oxygen Reduction Reaction

2021 ◽  
Vol 33 (4) ◽  
pp. 919-924
Author(s):  
L. Stanlykeninxavier ◽  
P. Elangovan ◽  
M.S.S. Saravanakumaar
Keyword(s):  
Catalytic Activity ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
High Performance ◽  
High Efficiency ◽  
Low Cost ◽  
High Capacity ◽  
Reduction Reaction ◽  
Highly Active ◽  
Electrocatalytic Oxygen Reduction

For the commercialization of alkaline fuel cells and metal air batteries, the advances in non-precious, cheap, stable electrocatalysts for the oxygen reduction reaction (ORR) and highly active remain a major problem. To overcome this problem, a facile approach was established to fabricate non-precious metal electrocatalysts, such as nanoparticles, pristine V2O5 and their WO3 hybrids. This is the first study reporting the utilization of monoclinic-WO3-nanocrystal-coupled V2O5 that serves as ORR catalysts. Compared with 50 wt.% WO3 with 50 wt.% V2O5 (VW-2) spheres and pristine V2O5, the hybrid catalyst of 25 wt.% WO3 and 75 wt.% V2O5 (VW-1) spheres exhibits outstanding catalytic activity towards ORR. In addition, the hybrid of 25 wt.% WO3 and 75 wt.% V2O5 (VW-1) exhibits a higher long-term durability and catalytic activity than high-quality commercial Pt/C catalysts, which renders the composites of WO3/V2O5 composites hybrid a high-capacity candidate for non-precious, high-performance, metal-based electrocatalysts having high efficiency and low cost for electrochemical energy conversion. The enhanced activity of WO3/V2O5 composites is mainly obtained from the improved structural openness in the V2O5 tunnel structure when coupled with WO3.

scholarly journals Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 37
Author(s):  
Mayra K. S. Monteiro ◽  
Djalma R. Da Silva ◽  
Marco A. Quiroz ◽  
Vítor J. P. Vilar ◽  
Carlos A. Martínez-Huitle ◽  
...  
Keyword(s):  
Electrochemical Sensor ◽  
Linear Response ◽  
High Performance ◽  
Low Cost ◽  
Pharmaceutical Formulations ◽  
Caffeine Concentration ◽  
Real Samples ◽  
Wide Range ◽  
Potential Use

This study aims to investigate the applicability of a hybrid electrochemical sensor composed of cork and graphite (Gr) for detecting caffeine in aqueous solutions. Raw cork (RAC) and regranulated cork (RGC, obtained by thermal treatment of RAC with steam at 380 °C) were tested as modifiers. The results clearly showed that the cork-graphite sensors, GrRAC and GrRGC, exhibited a linear response over a wide range of caffeine concentration (5–1000 µM), with R2 of 0.99 and 0.98, respectively. The limits of detection (LOD), estimated at 2.9 and 6.1 µM for GrRAC and GrRGC, suggest greater sensitivity and reproducibility than the unmodified conventional graphite sensor. The low-cost cork-graphite sensors were successfully applied in the determination of caffeine in soft drinks and pharmaceutical formulations, presenting well-defined current signals when analyzing real samples. When comparing electrochemical determinations and high performance liquid chromatography measurements, no significant differences were observed (mean accuracy 3.0%), highlighting the potential use of these sensors to determine caffeine in different samples.

scholarly journals Carbon nanomaterial hybrids via laser writing for high-performance non-enzymatic electrochemical sensors: a critical review

2021 ◽  
Author(s):  
Marcel Simsek ◽  
Nongnoot Wongkaew
Keyword(s):  
Noble Metal ◽  
Critical Review ◽  
High Performance ◽  
Carbon Nanomaterials ◽  
Electrochemical Sensors ◽  
Low Cost ◽  
Three Dimensional ◽  
Laser Writing ◽  
Enzyme Mimicking ◽  
Natural Enzyme

AbstractNon-enzymatic electrochemical sensors possess superior stability and affordability in comparison to natural enzyme-based counterparts. A large variety of nanomaterials have been introduced as enzyme mimicking with appreciable sensitivity and detection limit for various analytes of which glucose and H2O2 have been mostly investigated. The nanomaterials made from noble metal, non-noble metal, and metal composites, as well as carbon and their derivatives in various architectures, have been extensively proposed over the past years. Three-dimensional (3D) transducers especially realized from the hybrids of carbon nanomaterials either with metal-based nanocatalysts or heteroatom dopants are favorable owing to low cost, good electrical conductivity, and stability. In this critical review, we evaluate the current strategies to create such nanomaterials to serve as non-enzymatic transducers. Laser writing has emerged as a powerful tool for the next generation of devices owing to their low cost and resultant remarkable performance that are highly attractive to non-enzymatic transducers. So far, only few works have been reported, but in the coming years, more and more research on this topic is foreseeable. Graphical abstract

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