Oxidation Modification of Polyacrylonitrile-Based Carbon Fiber and Its Electro-Chemical Performance as Marine Electrode for Electric Field Test

A novel sensor for ocean electric field testing has been fabricated by polyacrylonitrile-based on carbon fibers with electro-chemical oxidation.The surface profile characteristics of the carbon fibers were characterized by scanning electron microscope,Fourier transform infrared spectra and contact angle.Cyclic voltammetry and Tafel curves have been used to study its electro-chemical performances.Two identical electrodes in sea water as the electric field sensor will swiftly respond to applied electric field which causes positive and negative ions to move in opposite direction,resulting in a electric potential difference(ΔE).Test result indicates that the offset potential is typically below 1 m V with a drift of 60-170μVd^-1.Typical self noise level is 1.07 nV√Hz^(1/2)@1 Hz.The electric field response indicates that the modified electrode pair shows better response to AC sine signal of amplitude and frequency(5 mV and 1 mHz)respectively than its blank.The electric field response model of the modified electrodes is creatively presented according to its electric double layer capacitance and Faraday pseudo-capacitance.Many advantages of the carbon fiber electric field electrode will make it have potential application prospect.

Industrial Recycling Process of Batteries for EVs

The growing number of decarbonization standards in the transportation sector has resulted in an increase in demand for electric cars.Renewable energy sources have the ability to bring the fossil fuel age to an end.Electrochemical storage devices,particularly lithium-ion batteries,are critical for this transition’s success.This is owing to a combination of favorable characteristics such as high energy density and minimal self-discharge.Given the environmental degradation caused by hazardous wastes and the scarcity of some resources,recycling used lithium-ion batteries has significant economic and practical importance.Many efforts have been undertaken in recent years to recover cathode materials(such as high-value metals like cobalt,nickel,and lithium).Regrettably,the regeneration of lower-value-added anode materials(mostly graphite)has received little attention.However,given the widespread use of carbon-based materials and the higher concentration of lithium in the anode than in the environment,anode recycling has gotten a lot of attention.As a result,this article provides the most recent research progress in the recovery of graphite anode materials from spent lithium ion batteries,analyzing the strengths and weaknesses of various recovery routes such as direct physical recovery,heat treatment recovery,hydrometallurgy recovery,heat treatment-hydrometallurgy recovery,extraction,and electrochemical methods from the perspectives of energy,environment,and economy;additionally,the reuse of recycled anode mats is discussed.Finally,the problems and future possibilities of anode recycling are discussed.To enable the green recycling of wasted lithium ion batteries,a low energy-consuming and ecologically friendly solution should be investigated.

ECA在饮料生产清洗消毒中的应用

饮料生产设备使用热水和碱液的传统清洗消毒方式,会造成大量的蒸汽、化学药品(氢氧化钠)、水的耗用,并且增加了生产制造成本,企业在追求效益的同时需要降低生产成本和减少环境的污染。采用一种新的电解活化水(Electro-Chemical Activation Water,ECA))清洗消毒代替传统的清洗消毒方式,将有助于降低生产成本,减少对环境的污染,并且清洗效果及运行良好稳定。

Substituent Effects on Reduction Potentials of Meta-substituted and Para-substituted Benzylideneanilines

Effects of meta-substituent of 3,4＇/4,3＇/3,3＇-substituted benzylideneanilines （XBAYs） on the electrochemical reduction potentials （E（Red）） were investigated, in which 49 samples of target compounds were synthesized, and their reduction potentials were measured by cyclic voltammetry. The substituent effects on the E（Red） of target compounds were analyzed and an optimality equation with four parameters （Hammett constant a of X, Hammett constant a of Y, excited-state substituent constant σexCC of X, and the substituent specific cross-interaction effect △σexCC2 between X and Y） was obtained. The results show that the factors affecting the E（Red） of 3,4＇/4,31/3,3P-substituted XBAYs are different from those of 4,4＇-substituted XBAYs. For 3,4＇/4,3＇/3,3＇-substituted XBAYs, σ（X） and σ（Y） must be employed, and the contribution of △σexCC2 is important and not negligible. Compared with 4,4＇-substituted XBAYs, X group contributes less to 3,4＇/4,3＇/3,3＇-substituted XBAYs, while Y group contributes more to them. Additionally, it was observed that either para-substituted XBAYs or meta-substituted XBAYs, the substituent effects of X are larger than those of Y on the E（Red） of substituted XBAYs.

Effect of stoichiometry and Cu-substitution on the phase structure and hydrogen storage properties of Ml-Mg-Ni-based alloys

To improve the electrochemical properties of rare-earth-Mg-Ni-based hydrogen storage alloys, the effects of stoichiometry and Cu-substitution on the phase structure and thermodynamic properties of the alloys were studied. Nonsubstituted Ml0.80Mg0.20（Ni2.90Co0.50-Mn0.30Al0.30）x （x=0.68, 0.70, 0.72, 0.74, 0.76） alloys and Cu-substituted Ml0.80Mg0.20（Ni2.90Co0.50-yCuyMn0.30Al0.30）0.70 （y=0, 0.10, 0.30, 0.50） alloys were prepared by induction melting. Phase structure analysis shows that the nonsubstituted alloys consist of a LaNi5 phase, a LaNi3 phase, and a minor La2Ni7 phase;in addition, in the case of Cu-substitution, the Nd2Ni7 phase appears and the LaNi3 phase vanishes. Ther-modynamic tests show that the enthalpy change in the dehydriding process decreases, indicating that hydride stability decreases with in-creasing stoichiometry and increasing Cu content. The maximum discharge capacity, kinetic properties, and cycling stability of the alloy electrodes all increase and then decrease with increasing stoichiometry or increasing Cu content. Furthermore, Cu substitution for Co ame-liorates the discharge capacity, kinetics, and cycling stability of the alloy electrodes.

Integration of Real-Time Chemical Sensors for Deep Sea Research

There is a great demand for in-situ real-time chemical sensors in the oceanographic research, to measure the chemical components under the deep sea. The ISE (Ion Selective Electrode) is commonly used as a detecting part of deep-sea electro-chemical sensors. The paper highlights the solidification and micromation of the working and reference electrodes. The sensors of pH and H 2S with a thermal probe are accomplished after the solution of configuration of electrodes and signal processing. The sensor system has been tested successfully in the cruise of DY105-12, 14 sponsored by China Ocean Mineral Research and Exploitation Association(COMRA).

Preparation and characterization of spinel LiMn_2O_4 nanorods as lithium-ion battery cathodes

The hydrothermal synthesis of single-crystallineβ-MnO2 nanorods and their chemical conversion into single-crystalline LiMn2O4 nanorods by a simple solid-state reaction were reported.This method has the advantages of producing pure,single-phase and crystalline nanorods.The LiMn2O4 nanorods have an diameter of about 300 nm.The discharge capacity and cyclic performance of the batteries were investigated.The LiMn2O4 nanorods show better cyclic performance with a capacity retention ratio of 86.2% after 100 cycles.Battery cyclic studies reveal that the prepared LiMn2O4 nanorods have high capacity with a first discharge capacity of 128.7 mA·h/g.

Corrosion behavior of magnesium-graphene composites in sodium chloride solutions

Coating of graphene and graphene/polymer composites on metals improves the corrosion resistance of metal substrates.On other hand,graphene embedded inside metal(especially Mg)matrices increases or decreases corrosion,is a crucial factor and must be explored.In present study,electrochemical behaviors of magnesium alloys(AZ31 and AZ61)and their composites reinforced with graphene nanoplatelets(GNPs)were carried out in 3.5%NaCl solution by polarization method.The surface morphology of composites before and after corrosion tests were analyzed using scanning electron microscopy.Experimental results revealed that presence of graphene nanoplatelets in different matrices decrease corrosion resistance of composites.This may be attributed to presence of graphene nanoplatelets which activates the corrosion of magnesium/alloys due to the occurrence of galvanic corrosion and this effect increases with increasing graphene nanoplatelets content.Further,an appropriate model describing the corrosion mechanism was proposed.

Slow-rise and fast-drop current feature of ultraviolet response spectra for ZnO-nanowire film modulated by water molecules

This study describes the fabrication of ZnO-nanowire films by electro-chemical anodization of Zn foil. The ZnO films are characterized by field emission scanning electron microscopy, X-ray diffraction patterns, and transmission electron microscopy, respectively. The ultraviolet （UV） photo-response properties of the surface-contacted ZnO film are studied through the current evolution processes under different relative humidities. Unlike the usually observed current spectra of the ZnO films, the drop time is shorter than the rise time. The photo-conductivity gain G and the response time T are both increased with the increase of the applied bias. The photo-conductivity gain G is lowered with the increase of the environmental humidity, while the response time τ- is increased. These results can be explained by considering three different surface processes： 1） the electron-hole （e-p） pair generation by the UV light illumination, 2） the following surface O2 species desorption, and 3） the photo-catalytic hydrolysis of water molecules adsorbed on the ZnO surface. The slow-rise and fast-drop current feature is suggested to originate from the sponge-like structure of the ZnO nanowires.

3-Aminopropyltriethoxysilane Complexation with Iron Ion Modified Anode in Marine Sediment Microbial Fuel Cells with Enhanced Electrochemical Performance

Anode modification plays a key role in higher power output in marine sediment microbial fuel cells(MSMFCs).A low-molecular organosilicon compound(3-aminopropyltriethoxysilane)was grafted onto the surface of carbon felt using chemical method and a composite modified anode was prepared through organic ligands coordination Fe^(3+)for better electro-chemical per-formance.Results show that the biofilm resistance of the composite modified anode(2707Ω)is 1.3 times greater than that of the unmodified anode(2100Ω),and its biofilm capacitance also increases by 2.2 times,indicating that the composite modification pro-motes the growth and attachment of electroactive bacteria on the anode.Its specific capacitance(887.8 Fm^(−2))is 3.7 times higher than that of unmodified anode,generating a maximum current density of 1.5Am^(−2).In their Tafel curves,the composite modified anodic exchange current density(5.25×10^(−6)Acm^(−2))is 5.8 times bigger than that of unmodified anode,which suggests that the electro-chemical activity of redox,anti-polarization ability and electron transfer kinetic activity are significantly enhanced.The marine sediment microbial fuel cell with the composite modified anode generates the higher power densities than the blank(203.8mWm^(−2) versus 45.07mWm^(−2)),and its current also increases by 4.4 times.The free amino groups on the anode surface expands a creative idea that the modified anode ligates the natural Fe(Ⅲ)ion in sea water in the MSMFCs for its higher power output.

Improvement of fabrication and characterization methods for micromechanical disk resonators

In this paper we present a novel method to fabricate reliable micro-electro-mechanical system（MEMS） disk resonators with high yield and good performance.The key breakthrough in the fabrication process is a novel approach to effectively restraining electro-chemical corrosion of polycrystalline silicon（polysilicon） electrically coupled with noble metals of MEMS devices by hydrofluoric acid（HF）-based solutions.In addition,a measurement architecture based on a differential readout topology is demonstrated.The differential circuit proposed here can effectively suppress noise and feed-through current by common-mode rejection of the differential amplifier.This differential amplifier circuit configuration is also used to build up a notch filter.The preliminary result about the temperature dependence of the resonance frequency is discussed,and the device failure is analysed.

Electropolishing technique of Hastelloy C-276 alloy

Preparing a highly textured,flawless YBa_（2-）Cu_3O_7（YBCO）layer by ion-beam-as sis ted deposition（IBAD）requires a substrate with a smooth surface.In this paper,smooth tapes of Hastelloy C-276,a common template alloy,were prepared by electrochemical polishing,and the surface roughness the tapes was investigating by atomic force microscopy and scanning electron microscopy.By analyzing these results,it was discussed how the processing parameters affect the surface roughness,and it is found the following optimized processing parameters：current density of 0.104 A·cm^（-2）,temperature of 50℃,plate spacing of 9 cm and time of 150 s.With these optimized parameters,the substrate roughness decreases to less than 5 nm,meeting the requirements of IBAD.

Hydrothermal growth of MoS_2/Co_3S_4 composites as efficient Pt-free counter electrodes for dye-sensitized solar cells

MOS2/Co3S4 composite films were prepared via a facile one-step hydrothermal method, and used as efficient and low-cost Pt-free counter electrodes （CEs） for dye-sen- sitized solar cells （DSSCs）. Characterizations revealed that Co3S4 and MoS2 were obtained simultaneously during the facile hydrothermal process. The composites afforded a promising synergistic effect on the catalyzing of triiodide reduction. Enhanced electrocatalytic performance of the resultant composite films was confirmed through cyclic voltammetry （CV） and electrochemical impedance spec- troscopy （EIS） analyses. DSSCs using MoS2/Co3S4 composite CEs outperform the devices with pristine MoS2 or Co3S4 CEs in power conversion efficiency （PCE）. Furthermore, a PCE of 6.77% is obtained for the optimized devices using MoS2/Co3S4 composite CEs measured under standard 1 sun illumination （100 mW cm-2, AM 1.5G）, which is comparable to that of the devices fabricated under the same conditions with conventional thermally deposited Pt CEs （7.14%）. The results demonstrate that MoS2/Co3S4 composites are promis- ing alternatives to Pt to be applied as CEs for DSSCs,

Improvement in electrochemical capacitance of activated carbon from scrap tires by nitric acid treatment

Activated carbon （AC） obtained from the industrial pyrolytic tire char is treated by concentrated nitric acid （AC-HNO3） and then used as the electrode material for supercapacitors. Surface properties and electrochemical capacitances of AC and AC- HNO3 are studied. It is found that the morphology and the porous texture for AC and AC- HNO3 have little difference, while the oxygen content increases and functional groups change after the acid treatment. Electrochemical results demonstrate that the AC-HNO3 electrode displays higher specific capacitance, better stability and cycling performance, and lower equivalent series resistance, indicating that AC obtained from the industrial pyrolytic tire char treated by concentrated nitric acid is applicable for supercapacitors.

Synthesis, Structural Characterization,and Electrochemical Properties of Binuclear Copper(Ⅱ) Complexes Containing Tetradentate Schiff Base Ligand

Two binuclear copper（Ⅱ） complexes, [Cu2（saloph）2 （μ-O）2]·2（DMF）[Hasaloph N,N＇-o-phenylenebis（salicylideneaminato）] （a） and [Cu2（salen）2（μ-O）2] [H2salen=N,N＇-bis（salicylic-deneaminato） ethylene] （b）were synthesized and characterized by X-ray crystal-lography. Both of them have distorted rectangular pyramidal geometry around Cu（Ⅱ）. The complete series of complexes show bridging phenoxo groups between the copper centers, together with hydroxo-bridges in these complexes. The complexes have also been characterized by elemental analysis, IR, TG-DTA, and electrochemical results.