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Articles 1351 - 1380 of 3176

Full-Text Articles in Engineering Science and Materials

Palladium Adatoms On Gold Nanoparticles As Electrocatalysts For Ethanol Electro-Oxidation In Alkaline Solutions, Hui-Mei Chen, Shang-Qian Zhu, Jia-Le Huang, Min-Hua Shao Dec 2018

Palladium Adatoms On Gold Nanoparticles As Electrocatalysts For Ethanol Electro-Oxidation In Alkaline Solutions, Hui-Mei Chen, Shang-Qian Zhu, Jia-Le Huang, Min-Hua Shao

Journal of Electrochemistry

Palladium (Pd) is a good catalyst for ethanol electro-oxidation in alkaline solutions. The activity of Pd is further improved in this study by modifying the gold (Au) nanoparticles with Pd adatoms using a simple spontaneous deposition process. The Pd overlayer on the Au core (Au@Pd) is un-uniform with some Au atoms exposed to the electrolyte. The activity of Au@Pd/C toward ethanol oxidation reaction (EOR) is much higher than that of Pd/C in an alkaline solution. The peak current density of Au@Pd/C is 4.6 times higher than that of Pd/C with a 100 mV lower onset potential. The enhanced activity may …

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Fuel Cells Reactor For Chemicals And Electric Energy Cogeneration, Zhi-Lin Heng, Xiao-Zi Yuan, Yi-Mei Yin, Zi-Feng Ma Dec 2018

Fuel Cells Reactor For Chemicals And Electric Energy Cogeneration, Zhi-Lin Heng, Xiao-Zi Yuan, Yi-Mei Yin, Zi-Feng Ma

Journal of Electrochemistry

As an energy conversion device, fuel cells can efficiently convert chemical energy into electrical energy. With the developing of technology, it is used as a reactor to conduct the synthesis of high value-added chemicals while generating electrical energy. Having benefits such as mild reaction conditions, controllability of the reaction process, high selectivity of the product, as well as high efficiency of energy utilization, it is widely used in many fields such as preparation of high value-added industrial products, gas separation, water treatment, etc. This paper introduces the current trends and statuses of fuel cell reactors in the cogeneration of chemicals …

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Durability Performance Of The High-Power Fuel Cell System, Ke-Yong Wang, Wei-Yu Shi, Ren-Fang Wang, Jia Liu, Zhong-Jun Hou Dec 2018

Durability Performance Of The High-Power Fuel Cell System, Ke-Yong Wang, Wei-Yu Shi, Ren-Fang Wang, Jia Liu, Zhong-Jun Hou

Journal of Electrochemistry

Fuel cell durability is the crucial challenge in fuel cell vehicle, and the lifetime of more than 5000 hours is believed to be necessary for vehicle application. Few works on durability test of the full fuel cell system have been reported. In this work, the long lifetime HySYS-30 fuel cell system was developed in Sunrise Power based on the improved MEA durability and system control strategy. The durability performance of the system was investigated under vehicle duty cycle for more than 6000 hours, and only 8.1% performance loss was observed, implying that the durability of HySYS-30 fuel cell system could …

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Recent Progress In Pt-Based Catalysts For Oxygen Reduction Reaction, Jing Li, Xin Feng, Zi-Dong Wei Dec 2018

Recent Progress In Pt-Based Catalysts For Oxygen Reduction Reaction, Jing Li, Xin Feng, Zi-Dong Wei

Journal of Electrochemistry

One major challenge for a large-scale commercialization of the proton-exchange membrane fuel cells (PEMFCs) technologies that enable a shift to ‘zero-emission’ personal transportation, is the expensive and unstable Pt catalysts, which are mainly used to catalyze the sluggish kinetics of the oxygen reduction reaction (ORR) occurred on the air electrode of PEMFCs. Many research works have targets to improve the stability of Pt-based catalysts and to construct Pt/transitional metal alloys with low Pt loading amount. Herein, we provide a minireview for the Pt-based ORR catalysts based on our recent work, which covers a brief background introduction, the stability improvement of …

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Facile Synthesis Of Pt-Cu Alloy Nanodendrites As High-Performance Electrocatalysts For Oxygen Reduction Reaction, Liu-Xuan Luo, Guang-Hua Wei, Shui-Yun Shen, Feng-Juan Zhu, Chang-Chun Ke, Xiao-Hui Yan, Jun-Liang Zhang Dec 2018

Facile Synthesis Of Pt-Cu Alloy Nanodendrites As High-Performance Electrocatalysts For Oxygen Reduction Reaction, Liu-Xuan Luo, Guang-Hua Wei, Shui-Yun Shen, Feng-Juan Zhu, Chang-Chun Ke, Xiao-Hui Yan, Jun-Liang Zhang

Journal of Electrochemistry

Structures and compositions have significant effects on the catalytic properties of nanomaterials. Herein, a facile etching-based method was employed to synthesize Pt-Cu nanodendrites (NDs) with uniform and homogeneous alloy structures for enhancing oxygen reduction reaction (ORR). The formation of dendritic morphology was ascribed to the etching effect caused by the oxidative etchants of the Br-/O2 pair. The atomic ratio of Pt/Cu in Pt-Cu NDs could be easily tuned by altering the ratio of the Pt/Cu precursors, without deteriorating the dendritic morphology. The most active carbon-supported Pt1Cu1 NDs (Pt1Cu1 NDs/C) exhibited the …

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Optimization Of Useful Hard X-Ray Photochemistry, David Lewis Goldberger Dec 2018

Optimization Of Useful Hard X-Ray Photochemistry, David Lewis Goldberger

UNLV Theses, Dissertations, Professional Papers, and Capstones

X-ray induced damage is generally considered a nuisance, but in the field of Useful Hard X-ray Photochemistry we harness the highly ionizing and penetrating properties of hard X-rays (> 7 keV) to initiate novel photochemical decomposition and synthesis at ambient and extreme conditions. Preliminary experiments suggest that the energy of irradiating photons and the sample pressure play roles in determining the nature of X-ray induced damage. Here, we present the X-ray energy dependence of damage induced in strontium oxalate, strontium nitrate, and barium nitrate, as well as the pressure dependence of X-ray induced damage of strontium oxalate. Our results indicate …

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Multifunctional Nanocomposites Based On Bacterial Cellulose, Qisheng Jiang Dec 2018

Multifunctional Nanocomposites Based On Bacterial Cellulose, Qisheng Jiang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cellulose is biodegradable, renewable, and abundant in nature thus cellulose (or paper)-based products can be inexpensively produced and recycled. Among cellulosic materials, bacterial nanocellulose (BNC) draws a special research attention due to the inherent three-dimensional nanofibrous structure, excellent mechanical flexibility, high purity and well-defined surface chemistry, and cost-efficient, scalable and environment-friendly synthesis. BNC can be biosynthesized by Gluconacetobacter xylinus, which is the most characterized BNC producer among various microorganisms. BNC is composed of highly pure cellulose nanofibrils, produced from well-defined dextrose through biochemical steps and subsequent self-assembling of the secreted cellulose fibrils which has the dimension ranges from 25 to …

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Multifunctional Nanocomposites Based On Bacterial Cellulose, Qisheng Jiang Dec 2018

Multifunctional Nanocomposites Based On Bacterial Cellulose, Qisheng Jiang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cellulose is biodegradable, renewable, and abundant in nature thus cellulose (or paper)-based products can be inexpensively produced and recycled. Among cellulosic materials, bacterial nanocellulose (BNC) draws a special research attention due to the inherent three-dimensional nanofibrous structure, excellent mechanical flexibility, high purity and well-defined surface chemistry, and cost-efficient, scalable and environment-friendly synthesis. BNC can be biosynthesized by Gluconacetobacter xylinus, which is the most characterized BNC producer among various microorganisms. BNC is composed of highly pure cellulose nanofibrils, produced from well-defined dextrose through biochemical steps and subsequent self-assembling of the secreted cellulose fibrils which has the dimension ranges from 25 to …

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Reinventing The Wheel, Esther K. Unti, Ahmed Z. Shorab, Patrick B. Kragen, Adam M. Menashe Dec 2018

Reinventing The Wheel, Esther K. Unti, Ahmed Z. Shorab, Patrick B. Kragen, Adam M. Menashe

Mechanical Engineering

Reinventing the Wheel selected tires and designed wheels for the 2018 Cal Poly, San Luis Obispo Formula SAE combustion vehicle. Available tire options were evaluated for steady-state and transient performance as well as vehicle integration. A single-piece composite wheel with hollow spokes was designed to meet stiffness, strength, and tolerance requirements. A detailed study of wheel loading and geometric structural efficiency was performed. Finite element analysis was used to iterate the geometry and laminate. A two-piece male mold was designed and machined to manufacture the wheel. Removable silicone inserts were used to create the hollow spokes.

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Measuring Characteristic Shrinkage Variability Due To Metal Loading Effects In Low Temperature Co-Fired Ceramic Using Image Processing, John Ezekiel Zumbro Dec 2018

Measuring Characteristic Shrinkage Variability Due To Metal Loading Effects In Low Temperature Co-Fired Ceramic Using Image Processing, John Ezekiel Zumbro

Graduate Theses and Dissertations

Low temperature co-fired ceramic (LTCC) has many benefits when it comes to electronic packaging due to the low dielectric loss, reliability in extreme environments, and high breakdown voltage. Though the ceramic has a lot of benefits it is not widely used due to the high cost and complexities associated with manufacturing. One of these issues with manufacturing is compensating for the shrinkage of the ceramic, this is accomplished by using an expansion factor, creating the “green” or manufactured design. This expansion factor is approximated through knowledge of the ceramic factors such as the metal loading, layers of ceramic tape, firing …

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Comparative Study Of Power Semiconductor Devices In A Multilevel Cascaded H-Bridge Inverter, Kenneth Mordi Dec 2018

Comparative Study Of Power Semiconductor Devices In A Multilevel Cascaded H-Bridge Inverter, Kenneth Mordi

Graduate Theses and Dissertations

This thesis compares the performance of a nine-level transformerless cascaded H-bridge (CHB) inverter with integrated battery energy storage system (BESS) using SiC power MOSFETs and Si IGBTs. Two crucial performance drivers for inverter applications are power loss and efficiency. Both of these are investigated in this thesis. Power devices with similar voltage and current ratings are used in the same inverter topology, and the performance of each device is analyzed with respect to switching frequency and operating temperature. The loss measurements and characteristics within the inverter are discussed. The Saber® simulation software was used for the comparisons. The power MOSFET …

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Analysis Of Casting Defect, Tensile Strength, And Hardness Of Al-Si Casting Alloy With Percentage Variation Of Clay Binder Bangkalan, Imam Muhtarom, Sunomo Sunomo Nov 2018

Analysis Of Casting Defect, Tensile Strength, And Hardness Of Al-Si Casting Alloy With Percentage Variation Of Clay Binder Bangkalan, Imam Muhtarom, Sunomo Sunomo

Journal of Mechanical Engineering Science and Technology (JMEST)

Casting is one of method that used in forming the work piece by melting specific metal and pouring into moulding that has been prepared. This study aimed to determine the effect of the use of Bangkalan clay as binder in sand moulding against tensile strength, hardness, and defects in Al-Si casting alloy by using gravity casting method. The method used in this study was experimental method then using descriptive analysis. Descriptive analysis included explanation of the test result of tensile strength, hardness, and the type of surface defect of Al-Si casting. Based on the research result obtained the highest shear …

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Analysis Of Hardness, Quality And Fluidity Al-Si Casting Result By Using Clamshell (Placuna Placenta) As The Mixture Of Sand Moulding, Shikh Mohd Shahrul Nizan Shikh Zahari, Saif Aziz Saputra, Putut Murdanto Nov 2018

Analysis Of Hardness, Quality And Fluidity Al-Si Casting Result By Using Clamshell (Placuna Placenta) As The Mixture Of Sand Moulding, Shikh Mohd Shahrul Nizan Shikh Zahari, Saif Aziz Saputra, Putut Murdanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Metal is an element that cannot be separated from human life. Almost all of human activities includes metal element in it. Metals can be formed through several ways, one of which is metal casting. Metal casting is one of technique in producing products where the metal was melted in crucible and then poured in a moulding which is similar to the original shape of the product. Moulding that are commonly used are sand moulding. Commonly, binder which used in sand casting process is bentonite. Bentonite, was kind of mineral which can be run out during its usage. This study aimed …

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Analysis Of Mechanical Properties And Permeability Of Sand Moulding By Using Eggshell In Sand Casting, Wahyu Kurnianto, Poppy Puspitasari, Wahono Wahono Nov 2018

Analysis Of Mechanical Properties And Permeability Of Sand Moulding By Using Eggshell In Sand Casting, Wahyu Kurnianto, Poppy Puspitasari, Wahono Wahono

Journal of Mechanical Engineering Science and Technology (JMEST)

This study aimed to analyse the usage of Eggshell as mixture material of bentonite in metal casting process which used dried sand moulding. Eggshell variations in this study were 4%, 7%, 10% eggshell, and additional 3% of bentonite on each sample. This study used pre-experimental method and included to OneShot Case Study model. The highest strength was found on the sample 3 ES 10%. Tensile strength of dried sand moulding reach up to 0.09 kg/cm2, the compressive strength of dried sand moulding reached up to 3.11 kg/cm2, and the shear strength of dried sand moulding reached up to 1.13 kg/cm2. …

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The Analysis Of Permeability And Mechanical Properties Of Sand Moulding Using Mixed Material Clamshell (Placuna Placenta) On Sand Casting, Kritchakhris Nawettanaprasert, Zakaria Bagus Aminanta, Putut Murdanto Nov 2018

The Analysis Of Permeability And Mechanical Properties Of Sand Moulding Using Mixed Material Clamshell (Placuna Placenta) On Sand Casting, Kritchakhris Nawettanaprasert, Zakaria Bagus Aminanta, Putut Murdanto

Journal of Mechanical Engineering Science and Technology (JMEST)

This study objected to determine mechanical properties of sand moulding by conducting tensile test, compressive and shear test, and also permeability test. This study also had the other objective that was analyse clamshell (Placuna placenta) as mixture material for bentonite as binder in manufacturing sand moulding in order to reduce the usage of bentonite. The method that used in this study was pre-experimental method with One-Shot Case Study model. The best mechanical properties obtained on sample 3 clamshell 11%, permeability results obtained was 190 ml/min, tensile strength results obtained for the dry sand was 0.015 kg/cm2, compressive strength obtained for …

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Metal Segregation During The Solidification Of Titanium-Aluminum Alloys For 3d Printing Applications, Jwala Parajuli Nov 2018

Metal Segregation During The Solidification Of Titanium-Aluminum Alloys For 3d Printing Applications, Jwala Parajuli

Master's Theses

Titanium-Aluminum alloys are one of the widely used alloys in multiple engineering applications. They are highly preferred in Selective Laser Melting (SLM) processes due to their low density, high melting temperature, and good strength. Segregation occurs during the solidification of most alloys and produces a non-uniform distribution of atoms. In SLM, segregation may depict the type of adhesion between the two deposited interfacial layers and the strength between the interphase between an already solidified layer and a new one, and overall, the quality of the printed part. In order to avoid segregation, the understanding of the segregation behavior at atomistic …

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Effective Magnetic And Electric Response Of Composite Materials, Mona Hassan Alsaleh Nov 2018

Effective Magnetic And Electric Response Of Composite Materials, Mona Hassan Alsaleh

Doctoral Dissertations

Metamaterials (MMs) are nanocomposite materials consisting of metal-dielectric resonators much smaller in size than the wavelength of the incident light. Common examples of metamaterials are based on split ring resonators (SRRs), parallel wires or strips and fishnet structures. These types of materials are designed and fabricated in order to provide unique optical responses to the incident electromagnetic radiation that are not available in naturally existing materials. The MMs can exhibit unusual properties such as strong magnetism at terahertz (THz) and optical frequencies. Additionally, negative index materials (NIMs) can provide negative index of refraction which can be used in many applications …

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Mechanical Characterization Of Expanded Polystyrene Spheres Embed Sandwich Composites For Packaging Applications, Maheswaran R, Arockia Reemas S Nov 2018

Mechanical Characterization Of Expanded Polystyrene Spheres Embed Sandwich Composites For Packaging Applications, Maheswaran R, Arockia Reemas S

Journal of Applied Packaging Research

This paper addresses on study of development of new packaging material comprising Expanded Polystyrene Spheres (EPS) embedded epoxy polymer based sandwich composites with aluminium skin. The density of the packing material is controlled by varying the volume of embedded spheres. In this study, the Flexural and Compression performance of Expanded Polystyrene Spheres (EPS) embedded polymer based sandwich composites with aluminium skin are investigated. The EPS volume percent in the core is 25% with epoxy matrix which makes the the density less than 1 g/cm3 for the composite. The fabricated Sandwich Composite are very light weight, the density is less than …

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Creating A Computational Tool To Simulate Vibration Control For Piezoelectric Devices, Ahmet Ozkan Ozer, Emma J. Moore Nov 2018

Creating A Computational Tool To Simulate Vibration Control For Piezoelectric Devices, Ahmet Ozkan Ozer, Emma J. Moore

Posters-at-the-Capitol

Piezoelectric materials have the unique ability to convert electrical energy to mechanical vibrations and vice versa. This project takes a stab to develop a reliable computational tool to simulate the vibration control of a novel “partial differential equation” model for a piezoelectric device, which is designed by integrating electric conducting piezoelectric layers constraining a viscoelastic layer to provide an active and lightweight intelligent structure. Controlling unwanted vibrations on piezoelectric devices (or harvesting energy from ambient vibrations) through piezoelectric layers has been the major focus in cutting-edge engineering applications such as ultrasonic welders and inchworms. The corresponding mathematical models for piezoelectric …

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Recent Process In Transition-Metal-Oxide Based Catalysts For Oxygen Reduction Reaction, Yao Wang, Zi-Dong Wei Oct 2018

Recent Process In Transition-Metal-Oxide Based Catalysts For Oxygen Reduction Reaction, Yao Wang, Zi-Dong Wei

Journal of Electrochemistry

Transition metal oxides (TMOs) based catalysts have become the most promising catalysts to be employed in anion exchange membrane fuel cell for the sluggish oxygen reduction reaction (ORR). However, their ORR activity is still far from that of the Pt-based catalysts. Therefore, it is important to develop high performance TMO based catalysts. Electrical conductivity and intrinsic activity have been regarded as the two keys to affect the ORR activity of the TMOs based catalysts. In this review, we focused on the recent progresses in the fundamental viewpoints on the electrical conductivity and intrinsic activity of the TMOs based ORR catalysts. …

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Recent Advances In Continuous Models Of Electrochemical Supercapacitors, Hao-Tian Lu, Jing-Hong Zhou, Guang-Hua Ye, Xing-Gui Zhou Oct 2018

Recent Advances In Continuous Models Of Electrochemical Supercapacitors, Hao-Tian Lu, Jing-Hong Zhou, Guang-Hua Ye, Xing-Gui Zhou

Journal of Electrochemistry

Electrochemical capacitors (supercapacitors) have been developed as a new type of energy storage device with high energy and power densities, which have the advantages of both fast charging-discharging as traditional capacitors and high energy density as batteries. Notable improvements in their electrochemical performance have been achieved in recent years owing to the recent advances in understanding of charge storage mechanisms and the development of advanced nanostructured materials. Recently, modeling and simulation of these supercapacitors has been applied as a useful approach to better understand the working mechanisms of the supercapacitors by describing the concentrations and electric fields inside the capacitors. …

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Recent Advances In Non-Noble Metal Nanomaterials For Oxygen Evolution Electrocatalysis, Dan-Dan Zhao, Nan Zhang, Ling-Zheng Bu, Qi Shao, Xiao-Qing Huang Oct 2018

Recent Advances In Non-Noble Metal Nanomaterials For Oxygen Evolution Electrocatalysis, Dan-Dan Zhao, Nan Zhang, Ling-Zheng Bu, Qi Shao, Xiao-Qing Huang

Journal of Electrochemistry

Hydrogen is a kind of renewable energies with the merits of environmentally friendly, abundance and high weight energy density, which can replace the fossil energy. The electrolysis of water is regarded as the most effective way to generate hydrogen. Owing to the sluggish kinetics and large overpotential of the anode oxygen evolution reaction (OER), the efficiency of the cathode hydrogen evolution reaction is greatly limited. Therefore, it is highly desirable to explore efficient, stable and low cost electrocatalysts to reduce the overpotential of OER and improve the efficiency of hydrogen evolution. Based on the natural characteristics of non-noble metal catalysts …

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Research Progresses In Improvement For Low Temperature Performance Of Lithium-Ion Batteries, Yue-Ru Gu, Wei-Min Zhao, Chang-Hu Su, Chuan-Jun Luo, Zhong-Ru Zhang, Xu-Jin Xue, Yong Yang Oct 2018

Research Progresses In Improvement For Low Temperature Performance Of Lithium-Ion Batteries, Yue-Ru Gu, Wei-Min Zhao, Chang-Hu Su, Chuan-Jun Luo, Zhong-Ru Zhang, Xu-Jin Xue, Yong Yang

Journal of Electrochemistry

Lithium-ion batteries (LIBs) have become a new research hotspot due to their high energy density and long service life. However, the temperature characteristics, especially the poor performance at low temperatures, have seriously limited their wider applications. In this report, the research progresses in the low temperature performance of LIBs are reviewed. The main existing limitations of LIBs at low temperatures were systematically analyzed, and followed by discussion on the recent improvements in low temperature performances by developing novel cathode, electrolyte, and anode materials. The developments for improving the low temperature performance of LIBs are prospected. The three most important factors …

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Synthesis Of Keggin Polyoxometalates Modified Carbon Paste Electrode As A Sensor For Dopamine Detection, Peng-Fei Dong, Na Li, Hai-Yan Zhao, Min Cui, Cong Zhang, Ju-Jie Ren, Xue-Ping Ji Oct 2018

Synthesis Of Keggin Polyoxometalates Modified Carbon Paste Electrode As A Sensor For Dopamine Detection, Peng-Fei Dong, Na Li, Hai-Yan Zhao, Min Cui, Cong Zhang, Ju-Jie Ren, Xue-Ping Ji

Journal of Electrochemistry

Polyoxometalates, a class of anionic clusters with structure diversity and size variability, make them very attractive in many fields such as electrochemistry, catalysis and medicine. The Co(C15N6H12)2[PW12O38]·5H2O(Co[PW12O38]) modified carbon paste electrode was prepared in this work, and its electrochemical performances as the sensor for dopamine detection were characterized with electrochemical impedance spectroscopy, cyclic voltammetry and differential pulse voltammetry. The preparation conditions and test conditions were optimized respectively. Under the optimized conditions, the POMs modified carbon paste electrode exhibited good selectivity and sensitivity …

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Effects Of Sulfur-Containing Additive On Low Temperature Performance Of Graphite Anode, Ze-Li Wu, Ye-Zhen Zheng, Zhong-Ru Zhang, Yong Yang Oct 2018

Effects Of Sulfur-Containing Additive On Low Temperature Performance Of Graphite Anode, Ze-Li Wu, Ye-Zhen Zheng, Zhong-Ru Zhang, Yong Yang

Journal of Electrochemistry

The low temperature performance of lithium ion battery mainly depends on the graphite anode, and one of the research focuses is to improve the low temperature performance of the anode by additives. In this paper, the effects of different sulfur-containing functional groups such as DTD (ethylene sulfate), 1,3-PS (1,3-propane sultone) and ES (ethylene sulfite) on low temperature performances of artificial graphite materials were systematically studied. The results in density functional theory (DFT) calculations, cyclic voltammetry (CV), scanning electron microscopy (SEM) and charge-discharge measurement clearly demonstrated that all three sulfur-containing additives could participate in formation of films on the surface of …

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Electrodeposition Of Cobalt From Eutectic-Based Ionic Liquid, Rostom Ali M., Sankar Saha S, Ziaur Rahman Md Oct 2018

Electrodeposition Of Cobalt From Eutectic-Based Ionic Liquid, Rostom Ali M., Sankar Saha S, Ziaur Rahman Md

Journal of Electrochemistry

The electrodeposition of cobalt from a solution containing cobalt chloride in either a urea-choline chloride based or an ethylene glycol (EG)-choline chloride based ionic liquid has been carried out onto copper and steel cathodes by constant current and constant potential methods at different temperatures. The influences of various experimental conditions on electrodeposition and morphology of the deposited layers have been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD)technique. It has been shown that the smooth, shiny with good adherence and bright metallic coloured cobalt coatings were obtained from both urea and EG based ionic liquids at the applied …

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Recent Progress In Organic Redox Flow Batteries, Li-Xing Xia, Hao Liu, Lin Liu, Zhan-Ao Tan Oct 2018

Recent Progress In Organic Redox Flow Batteries, Li-Xing Xia, Hao Liu, Lin Liu, Zhan-Ao Tan

Journal of Electrochemistry

Redox flow batteries (RFBs) are promising candidate for balancing instability of grids caused by integration of intermittent renewable energies such as solar energy and wind energy. Along with wide deployments in solar energy and wind energy due to abundance and declining installation cost, it can be predicted that RFBs will enter a period of rapid development. Basically,RFBs are electrochemical energy storage devices that decouple energy and power of the system by storing liquid electrolyte in tanks outside battery system itself. Such a unique framework makes RFBs flexible and fulfills the various demands of grids. During battery operation, redox-active species are …

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The New Application Of Battery-Electrode Reaction: Decoupled Hydrogen Production In Water Electrolysis, Yuan-Yuan Ma, Zhao-Wei Guo, Yong-Gang Wang, Yong-Yao Xia Oct 2018

The New Application Of Battery-Electrode Reaction: Decoupled Hydrogen Production In Water Electrolysis, Yuan-Yuan Ma, Zhao-Wei Guo, Yong-Gang Wang, Yong-Yao Xia

Journal of Electrochemistry

Hydrogen has been considered as a promising alternative to unsustainable fossil fuels because of its high calorific value, clean and abundant resources. Water electrolysis combined with renewable energy is regarded as the best way for hydrogen production, which will become the foundation of future hydrogen economy. For the past few years, many efforts have been employed to develop the cheap and high-performance catalyst for hydrogen evolution reaction and oxygen evolution reaction. However,the coupled hydrogen and oxygen evolution and the use of the expensive membrane have greatly restricted the flexibility of the conventional water electrolysis, and hindered the utilization of renewable …

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Design Strategies Toward Highly Active Electrocatalysts For Oxygen Evolution Reaction, Tang Tang, Wen-Jie Jiang, Shuai Niu, Jin-Song Hu Oct 2018

Design Strategies Toward Highly Active Electrocatalysts For Oxygen Evolution Reaction, Tang Tang, Wen-Jie Jiang, Shuai Niu, Jin-Song Hu

Journal of Electrochemistry

Electrocatalytic water splitting is pivotal for efficient and economical production of hydrogen and oxygen gasses. However, the efficiency of the whole device is largely limited by the oxygen evolution reaction (OER) at the anode due to its sluggish kinetics. Thus, it is imperative to develop inexpensive, highly active OER catalysts to lower the reaction barriers. By examining the underlying critical factors for OER performance, this review outlines general principles for designing efficient nanosized OER catalysts, including (1) enhancing the intrinsic activity of active site by electronic modulation, crystallinity modulation, phase control, defect engineering and spin state engineering; (2) designing appropriate …

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Photocatalytic Activity: Experimental Features To Report In Heterogeneous Photocatalysis, Md. Ariful Hoque, Marcelo I. Guzman Oct 2018

Photocatalytic Activity: Experimental Features To Report In Heterogeneous Photocatalysis, Md. Ariful Hoque, Marcelo I. Guzman

Chemistry Faculty Publications

Heterogeneous photocatalysis is a prominent area of research with major applications in solar energy conversion, air pollution mitigation, and removal of contaminants from water. A large number of scientific papers related to the photocatalysis field and its environmental applications are published in different journals specializing in materials and nanomaterials. However, many problems exist in the conception of papers by authors unfamiliar with standard characterization methods of photocatalysts as well as with the procedures needed to determine photocatalytic activities based on the determination of “apparent quantum efficiencies” within a wavelength interval or “apparent quantum yields” in the case of using monochromatic …

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