Materials Chemistry Commons^™

Preparation And Process Optimization Of Cathode Materials For Lithium-Sulfur Batteries, Kai Wu

Journal of Electrochemistry

Lithium-sulfur (Li-S) batteries represent promising candidates for next-generation energy storage system due to their high energy density and low material cost. However, the industrial application of Li-S batteries remains challenges because of the shuttle effect from lithium polysulfides and the lack of facial routes for Li-S battery preparation. To solve these problems, a cathode consisting of different commercial carbon materials, namely, acetylene black (SP), Ketjen Black (KB) and carbon nanotube (CNT), with sulfur (S) is prepared separately for Li-S battery. After the process of 8-h ball milling for KB/S composite, together with the polyvinyl pyrrolidone (PVP) binder, the cathode could …

Novel Electrochemical Sensor Based On Integration Of Nanoporous Gold With Molecularly Imprinted Polymer For Detection Of Arsenic Ion(Iii), Wu-Wei Ma, Qi-Gang Chang, Xiong-Fang Shi, Yan-Bin Tong, Li Zhou, Bang-Ce Ye, Jian-Jiang Lu, Jin-Hu Zhao

Journal of Electrochemistry

Arsenic, a toxic chemical element, is detrimental to environment and human health in particular. Therefore, the development of simple, fast, and accurate arsenic ion (As³⁺) detection methods has attracted extensive attention. In this work, an electrochemical sensor based on molecular imprinted polymer (MIP) and nano-porous gold (NPG) modified indium tin oxide (ITO) electrode (MIP/NPG/ITO) was developed for determination of As³⁺ in water with different quality. NPG with high conductivity, large specific surface area and high biocompatibility was prepared in situ on ITO surface by a green electrodeposition method using simple and controllable steps. Then, a layer of …

Synergistic Effect Of Dissolving O2 And Wavelength On The Photo-Assisted Anodic Deposition Of Ceo2 Thin Films, Tong-Zheng Jin, Yu-Meng Yang, Sheng-Hui Fan, Guo-Ying Wei, Zhao Zhang

Journal of Electrochemistry

Cerium dioxide (CeO₂) thin films have been applied as new material in many technical fields such as solid oxide fuel cells, catalysts, UV absorbents, pharmacology, and coatings for corrosion protection of many metals and alloys. Electrodeposition is widely considered to be one of the best preparation methods for CeO₂ film. In this work, the CeO₂ films were prepared by photo-assisted anodic deposition in the bath solutions containing 0.05 mol·L^-1 cerium (III) nitrate, 0.1 mol·L^-1 ammonia acetate and 70% (V/V) ethanol onto 316L stainless steel (SS) surface. The synergistic effects of …

Preparations And Properties Of Low Cost Sulfide Solid Electrolytes Li6-XPs5-XClX, Na-Chuan Yang, Yu Wang, Yi Shuai, Kang-Hua Chen

Journal of Electrochemistry

With the shortage of energy and environmental pollution, the storage of electric energy is getting more attention all over the world. In order to improve the energy density and safety performance of batteries, uses of solid electrolyte become more and more popular. However, because the conductivity of solid electrolyte is not comparable to that of liquid electrolyte, the solid electrolyte application has certain limitations. With the efforts of researchers from various countries, there are several different solid electrolytes having better conductivity, for instance, sulfide solid electrolyte and oxide solid electrolyte. Sulfide solid electrolyte is a highly promising solid electrolyte material …

Step-By-Step Modification Of Graphite Felt Electrode For Vanadium Redox Flow Battery, Jing-Yuan Lou, Dong-Jiang You, Xue-Jing Li

Journal of Electrochemistry

As a well-known electrode material of the vanadium redox flow battery (VRFB),graphite felt electrode is the frequently-used electrode material in VRFB, and its low electrochemical activity is one of the key factors for the low power density of VRFB. In this work, we proposed a step-by-step modification method, which used KMnO₄ to oxidize graphite felt first and then placed in an activation solution to excite its reactivity, to improve the electrochemical performance of the graphite felt electrode. According to the results from cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) characterizations …

Degradation And Thermal Characteristics Of Lini0.8Co0.15Al0.05O2/Graphite Lithium Ion Battery After Different State Of Charge Ranges Cycling, Cun Wang, Wei-Jiang Zhang, Teng-Fei He, Bo Lei, You-Jie Shi, Yao-Dong Zheng, Wei-Lin Luo, Fang-Ming Jiang

Journal of Electrochemistry

The LiNi_0.8Co_0.15Al_0.05O₂ (NCA) cathode exhibits high energy density and large reversible capacity, which plays an essential role in the field of electric vehicles (EVs). However, low capacity retention and poor thermal stability limit its application. Few literatures are found for the capacity degradation mechanism of NCA/graphite batteries at home and abroad. The different state of charge (SOC) ranges cycle degradation behaviors of 18650-type NCA/graphite (2.4 Ah) battery were studied in this paper. The SOC ranges considered were 0% ~ 20% (low), 20% ~ 70% (medium), 70% ~ 100% (high), and 0% ~ 100% …

Preparations And Sodium Storage Properties Of Ni3S2@Cnt Composite, Ming-Tao Duan, Yan-Shuang Meng, Hong-Shuai Zhang

Journal of Electrochemistry

Transition metal sulfides (TMSs)-based electrode materials with highly reversible sodium storage have attracted extensive attentions as one of the most prospective electrode materials for sodium ion batteries (SIBs). However, low cycling stability and rate property caused by large volume expansion and poor electronic conductivity during the electrochemical reaction still hamper their further practical application. In this work, in-situ encapsulated Ni₃S₂ nanoparticles in carbon nanotubes (Ni₃S₂@CNT) have been successfully fabricated as an anode material for high-performance SIBs by a one-step solid-phase calcination process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), …

Core-Shell Structured Ru@Ptru Nanoflower Electrocatalysts Toward Alkaline Hydrogen Evolution Reaction, Xue-Liang Wang, Yuan-Yuan Cong, Chen-Xi Qiu, Sheng-Jie Wang, Jia-Qi Qin, Yu-Jiang Song

Journal of Electrochemistry

Water electrolysis for hydrogen production is beneficial for solving the problem of energy crisis and environmental issues. It is necessary to study highly active and cost-effective catalysts toward hydrogen evolution reaction (HER) to reduce the consumption of noble metals. Herein, we report the synthesis of core-shell structured Ru@Pt_0.24Ru nanoflowers electrocatalyst by stepwise reduction of Ru and Pt precursors in the mixture of oleylamine and benzyl alcohol at 160 ^oC. The average diameter of the resultant Ru@Pt_0.24Ru was 16.5±4.0 nm with a bulk atomic ratio between Pt and Ru of 0.24:1 and a surface ratio of …

Effect Of 18-Crown-6 Additive On Chromium Electrodeposition In Ionic Liquid, Yi-Jie Wang, Dong-Fang Niu, Xin-Sheng Zhang

Journal of Electrochemistry

Trivalent chromium ion (Cr³⁺) is used for electrodeposition due to its low toxicity. Electrodeposition in ionic liquids can greatly solve for hydrogen evolution problem. However,as a widely used Cr(III) precursor, chromium chloride hydrate (CrCl₃·6H₂O), still contains water. In the presence of water, Cr³⁺ will form a complex coordination structure with water molecules ([Cr(H₂O)₆]³⁺), which is a stable octahedral structure and is difficult to be directly reduced to chromium metal. Therefore, coordination agents should be added into the bath. In this work, the effect of 18-Crown-6 additive on …

Electrochemical Determination Of Dopamine Based On Metal-Substituted Polyoxometalates Composites, Yi-Fei Xing, Na Li, Xiao-Fang Wen, Hong-Yan Han, Min Cui, Cong Zhang, Ju-Jie Ren, Xue-Ping Ji

Journal of Electrochemistry

In this report, a dopamine electrochemical sensor based on metal-substituted polyoxometalates and reduced graphene oxide (RGO) composite was successfully constructed. The K₂H₂SiW₁₁NiO₃₉·xH₂O (SiW₁₁Ni) was synthesized by hydrothermal method, while the RGO was prepared by Hummers' method and chemical reduction method. The above-mentioned materials were characterized by SEM, FTIR and XRD. The as-synthesized SiW₁₁Ni and RGO composites were modified on the surface of glassy carbon electrode (GCE) by drop coating method, and the sensing interface (SiW₁₁Ni-RGO/GCE) was successfully constructed. The electrochemical properties of …

Pitting Behaviors Of Passivated And Trans-Passivated 304 Stainless Steel, Jing Shen, Zi-Ming Wang, Da-Jiang Zheng, Guang-Ling Song

Journal of Electrochemistry

In order to further understand the passivation and trans-passivation behaviors of 304 stainless steels, the samples were pretreated under different polarization potentials and their corrosion behaviors were investigated. It was found that the pitting potential of the untreated sample was the same as that of the sample treated with 1.1 V trans-passivation potential, while the pitting potential of the sample treated with 0.5 V passivation treatment was the highest. This observation was further verified by the SKP results. According to SEM observations, the surface of the untreated sample preserved a polishing morphology, while the surface of the 0.5 V passivation …

Atom Transfer Radical Processes: From Catalyst Design To Polymer Synthesis, Characterization, And Application, Michael Novak

Electronic Theses and Dissertations

Due to the toxicity of heavy metals and their prevalence in the environment there exists a need to develop highly active transition metal catalysts ultimately reducing the amount needed for chemical transformations. Additionally, there is interest in the scientific community for creating new materials that can remove these pollutants from industrial wastewater prior to its release into the environment. The work presented here focuses on the reduction and removal of heavy metals from industrial hazardous waste by designing novel highly active catalysts and developing polymeric adsorbents.

Highly active catalyst complexes consisting of novel hybrid ligands, 2-(dimethylamino)ethyl-bis-[2-(pyridylmethyl)amine] (M1-T2), and bis[2-(dimethylamino)ethyl]-2-(pyridylmethyl)amine (M2-T1), …

Control Of Corrosion On Ss316l Using Surface Initiated Polymers, Alexander Rupprecht

Electronic Theses and Dissertations

Pitting corrosion is arguably one of the most destructive and dangerous forms of corrosion, resulting in damage to structures, the environment, and public health. In addition, damage caused to structures such as bridges, pipelines, and boats, corrosion also has a profound effect on the biomedical community. Implanted metallic devices (i.e., vascular stents and artificial joints) are prone to pitting corrosion caused by aggressive ions present in extracellular fluid. To provide a corrosion-resistant surface on SS316L, films of poly(styrene), poly(methyl acrylate), and poly(methyl methacrylate) were formed using surface-initiated atom transfer radical polymerization (SI-ATRP). The resulting hydrophobic polymer films had a fractional …

Nanomaterial Composites Based On Potassium Hexaniobate, Perovskites, And Iron Triazole Spin Crossover Complexes, Alexis A. Blanco

LSU New Orleans Theses and Dissertations

Development of novel materials with sought after properties has been the forefront in the field of nanomaterials. Hybrid nanomaterial architectures, or nanocomposites, is an important subgroup within the material chemistry umbrella. One such example of nanocomposite systems is peapod-like structures that are composed of 0D nanoparticles (“peas”) and 2D nanosheets (“pods”). Nanopeapods may display unique properties that were not attainable within individual components. BaTiO₃ nanoparticles can be produced using solvothermal methods (20 h) in the presence of Ba(NO₃)₂, titanium (IV) butoxide, and oleic acid as the surfactant. Synthesis parameters were modified to allow for both …

Fluorinated Phthalonitriles And Phthalocyanines: Synthesis And Spectroscopic Properties, Marius Pelmus

Seton Hall University Dissertations and Theses (ETDs)

Since their discovery at the beginning of the 20^th century, phthalocyanines (Pc) have come a long way; today they are replacing the porphyrins (natural products) in most of their applications. The functionalization of the organic macrocycle, the use of different metals, and the change of the axial ligands resulted in Pc applications in a wide range of fields, ranging from photochemistry, paints, catalysis, to fuel cells and cosmetic products.

In Dr. Gorun’s group was developed a series of electron-deficient Pcs that benefit from a Teflon-like chemical shield, meant also to break the π-π interactions, namely the F₆₄PcM …

Characterizations Of Bimetallic Silver-Copper Nanoparticles, Omar Lezcano

Undergraduate Honors Theses

The goal of this study was to characterize alloy nanoparticles with different bimetallic ratios of silver (Ag) and copper (Cu) by determining the composition and alloy structures. One specific objective was to determine how the composition affects the electrical properties of the nanoparticles in terms of electrical resistance and nanoparticle sintering. The desire for this study stems from the need to make conductive pastes for low-cost solar panel manufacturing. We performed experiments to develop the aqueous synthesis of core-shell bimetallic nanoparticles.

We investigated the room temperature sintering properties with the nanoparticles of varying compositions. The nanoparticles were characterized with several …

The Analytical And Biomedical Applications Of Carbon Dots And Their Future Theranostic Potential: A Review, Sukunya Ross, Ren-Siang Wu, Shih-Chun Wei, Gareth M. Ross, Huan-Tsung Chang

Journal of Food and Drug Analysis

In recent years, carbon dots (C-dots) have gained appreciable interest owing to their unique optical properties, including tunable fluorescence, stability against photobleaching and photoblinking, and strong fluorescence. Simple and low-cost hydrothermal and electrochemical approaches have been widely used in the preparation of biocompatible and high-quality C-dots. Various C-dots have been used for the quantitation of small analytes, mostly based on analyte induced fluorescence quenching. Depending on the nature of precursors, synthetic conditions (such as reaction temperature and time), and surface conjugation, multi-function C-dots can be prepared and used in diagnostics and therapeutics. Their strong fluorescence and photostability, enables use in …

Carbon Dots As Artificial Peroxidases For Analytical Applications, Shih-Chun Wei, Yang-Wei Lin, Huan-Tsung Chang

Journal of Food and Drug Analysis

Nanozymes have become attractive in analytical and biomedical fields, mainly because of their low cost, long shelf life, and less environmental sensitivity. Particularly, nanozymes formed from nanomaterials having high surface area and rich active sites are interesting since their activities can be tuned through carefully controlling their size, morphology, and surface properties. This review article focuses on preparation of carbon dots (C dots) possessing peroxidase-like activity and their analytical applications. We highlight the important roles of the oxidation states and surface residues of C dots and their nanocomposites with metal, metal oxides, or metal sulfides playing on determining their specificity …

Functionalized Gold Nanoparticles For Sensing Of Pesticides: A Review, Wei-Bin Tseng, Ming-Mu Hsieh, Che-Hsie Chen, Tai-Chia Chiu, Wei-Lung Tseng

Journal of Food and Drug Analysis

Pesticides are a family of non-biodegradable chemical compounds which widely used in agriculture to control pests and increase yield production. However, overuse or abuse of pesticides and their metabolites may cause potential toxicity for the environment as well as human health and all other living organisms, even at deficient concentrations. Consequently, the development of sensors for monitoring these compounds is significant. Recently, nanoparticles-based sensors have been extensively employed as a potential alternative or complementary analytical tool to conventional detection methods for pesticides. Among them, gold nanoparticles (AuNPs) owing to their unique optical properties have been developed as smart sensors with …

Practical Adhesion Measurements In Organic Coatings; Advancing Understanding And Mechanical Methods Development, Diana Gottschalk

Dissertations

“Adhesion” can be considered either a mechanical or chemical phenomenon. The mechanical interpretation describes the difficulty of separating surfaces and is useful for quantifying performance within applications that depend on bulk and interfacial properties. Chemical adhesion describes interfacial resistance to chemical attack and does not depend on bulk properties. Predicting chemical failure through mechanical measurement is confounded by the influence of bulk properties. However, the prospect is attractive because of the robust tolerance for sample geometries, allowing experiments to resemble an end-use system. The present work's primary goal was to elevate mechanical methods to provide a detailed interfacial characterization of …