摘要： 在4月8日举办的"2021科技体验日"现场,上汽通用公布了其在电动化、智能网联化领域的领先科技与战略布局。上汽通用汽车总经理王永清表示:"上汽通用汽车将充分整合母公司双方的优势资源,叠加打磨了24年的强大体系力,不断提速,‘双擎’驱动,将电动化与智能网联的前沿科技和创新服务快速转化为用户触手可及的安全、智能、互联的用车体验,带来更美好的智慧出行生活"。

关键词： Nozzles  

摘要： In hybrid laser-electrochemical micromachining, both laser and electrochemical process energies act along the same machining axis and thus both influence material removal by their interaction. The traditional nozzle based laser assisted jet-ECM concepts require laser to be focused on workpiece surface in an electrochemical environment and are limited in aspect ratios as the nozzle stays above the workpiece surface. In this work, a hybrid tooling concept is proposed for a novel process scheme of precision hybrid laser-electrochemical micromachining. The tool serves the function of both an ECM electrode as well as a leaky-type multimode waveguide for the laser and delivers laser homogeneously together with the electrolyte on the workpiece surface without requiring laser to be focused on the workpiece surface. A precision prototype hybrid machine-tool is developed which employs short pulsed nano-second laser and micro-second pulsed voltage source for precision micromachining. For this system, ray tracing and detailed multiphysics electrochemical micromachining process simulations are carried out to demonstrate the applicability of this hybrid tooling concept and explain the shape evolution. Successful experimental realization of coaxial and concurrent application of electrochemical and laser processes is presented. Prototype tool electrodes are fabricated and experiments are carried out on an in-house developed prototype hybrid machine tool. The results reveal that the proposed hybrid tool is successfully capable of concentrating laser and electrochemical process energies simultaneously in the same machining zone. However, with the initial design of this hybrid tool, a maximum of 30-40% of laser power is available in the machining zone. Some suggestions for further research will be presented.

关键词： defects   electrocatalysis   methanol oxidation reaction   nanowires   oxygen reduction reaction  

摘要： Sauerstoffreduktionsreaktion In ihrem Forschungsartikel auf S. 13882 berichten Q. Wang et al. über leerstellenreiche Pt‐Cu‐Nanodrahtnetzwerke (VCu‐PtCu), die eine überlegene elektrokatalytische Leistung in der Sauerstoffreduktionsreaktion zeigen.

关键词： Cathodes  

摘要： In the present work, well-recognized La0.8Sr0.2MnO3 (LSM) system as cathode for IT-SOFC is prepared by using different process control reagents (PCAs) such as stearic acid and salicylic acid with varying grinding times. This is the first attempt to develop LSM by using PCAs in mechanochemical synthesis. By using stearic acid single cubic phase, LSM material is obtained at 3 h of grinding (LSM-St). However in case of salicylic acid, the respective phase of La0.8Sr0.2MnO3 is achieved for 5 h of grinding (LSM-Sa) and without PCA the same phase is obtained for 7 h of grinding (LSM-Wt). X-Ray diffraction confirms single crystalline cubic phase of as-synthesized LSM by PCAs and without PCA. All the samples are sintered at 700 °C to improve the degree of crystallinity. Scanning electron microscopy images of as-synthesized samples reveal highly agglomerate fine-scale grains. The temperature dependence of direct current conductivity curve exhibits linear dependence of conductivity with temperature, which is found maximum for LSM-St as compared to other two samples. Symmetric cells in the configuration given by—composite cathode/electrolyte/composite cathode—are fabricated using spin coating technique. The area specific resistance is minimum for LSM-St based symmetric cell and correlated with the maximum conductivity. © 2020 Wiley-VCH GmbH

关键词： Ferro-cerium oxide   Nanocomposite   Sol-gel combustion method   Cadmium ions   Square wave anode stripping voltammetry  

摘要： Cd(II) is a biologically active element that requires rapid and reliable monitoring for its pollution control. We designed the electrochemical sensing nanocomposite with enhanced adsorption followed by redox processes, which was synthesized by incorporating ferric ions into cerium oxide substrate (hereafter CeFe2O5) via the sol-gel combustion method. The CeFe2O5 nanocomposite modified glassy carbon electrode (CeFe2O5/GCE) was used for selective detection of Cd(II) by square wave anode stripping voltammetry (SWASV). At optimal experimental conditions, the observed sensitivity and detection limits of CeFe2O5/GCE are 31.68 mu A/mu M and 0.94 nM, respectively. Our CeFe2O5/GCE exhibits excellent stability (RSD 3.34%) and analytical precision for Cd(II). The CeFe2O5/GCE can also be used in trace detection of heavy metal ions spiked in environmental samples. The nanocomposites with high electrochemical performance would be of great interest for constructing novel sensing platforms for monitoring heavy metal ions in environment. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Yttria stabilized zirconia  

摘要： Solid oxide cells (SOCs) have important applications as fuel cells and electrolyzers. The application for storage of renewable electricity is also becoming increasingly relevant;however, it is difficult to meet stringent area-specific resistance (ASR) and long-term stability targets needed to achieve required efficiency and cost. Here we show a new SOC that utilizes a very thin Gd-doped ceria (GDC)/yttria-stabilized zirconia (YSZ) bi-layer electrolyte, Ni-YSZ cell support with enhanced porosity, and electrode surface modification using PrO(x)and GDC nanocatalysts to achieve unprecedented low ASR values < 0.1 omega cm(2), fuel cell power density similar to 3 W cm(-2), and electrolysis current density similar to 4 A cm(-2)at 800 degrees C. Besides this exceptionally high performance, fuel cell and electrolysis life tests suggest very promising stability in fuel cell and steam electrolysis modes. Electrochemical impedance spectroscopy analysis done using a novel impedance subtraction method shows how rate-limiting electrode processes are impacted by the new SOC materials and design.

关键词： Porosity  

摘要： A large variety of synthetic methods have been developed for hierarchically porous materials by which the performance of a wide range of applications can be dramatically enhanced. Herein, hierarchically porous micropillar arrays are demonstrated by employing electrochemical etching to silicon micropillars. The approach relies on the steering of current flow through the three-dimensional silicon-electrolyte interface to enable nanopores to grow on the entire surface of the micropillars, simultaneously. The pores grow perpendicular to the surface of the micropillars, whereas the pore diameter and porosity vary depending on the locations of the surfaces. The finite element analysis shows that the spatial variation of the pore diameter and porosity is determined by the distribution of current density. Further, the thickness of the porous layer can be tuned by etching time so that sponge-like porous structures are conveniently obtained by regulating the etching time. In addition to the effect of current density flowing through the etched surfaces, the growth of pores also depends on the crystal orientations of the etched surfaces. The etching results on square micropillar arrays and microgroove arrays show that the growth direction and rate of nanopores inside the microstructure also depend on the exposed crystal planes. The facile characteristics of the fabrication method can serve as an effective route for a wide range of applications of porous materials with enhanced capabilities.

关键词： Electro-Fenton   Electroperoxidation   Trifluralin   Kinetic model   Industrial wastewater   Faradaic yield  

摘要： The aim of this manuscript was to investigate indirectly the kinetics of formation of hydroxyl/hydroperoxyl radicals responsible for the degradation of persistent pollutants by electrochemical peroxidation. Experiments involving iron electrodes with and without H2O2 were initially carried out in a batch reactor at 0.2-0.6 A and 25 degrees C in the absence of any pollutants. Concentrations of Fe2+, H2O2, Fe3+, and H+ were determined experimentally as a function of time, and from them a detailed kinetic model comprising 25 electrolysis, dissociation, flotation and Fenton reactions was established. The tuned parameters were only the Faradaic yields for the reactions on the anode, the rate constant for the forward reaction of water dissociation, and flotation of Fe3+. A set of three kinetic experiments of electroperoxidation of trifluralin performed at 0.2 to 0.6 A and 25 degrees C was correctly described by the already presented subset of reactions, plus two others involving trifluralin and hydroxyl/hydroperoxyl radicals. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Reactive electrochemical membrane   Advanced wastewater treatment   Antibiotics removal   Transformation products   Energy consumption  

摘要： The ozone-reactive electrochemical membrane (O-3-REM) coupled process for tetracycline (TC) removal was developed by coupling ozonation and electrochemical oxidation in a substoichiometric titanium dioxide (Ti4O7) REM reactor. To achieve concurrent and efficient degradation-mineralization, TC was treated by ozonation and electrochemical oxidation over the Ti4O7 REM anode in a sequent manner. TC was nearly completely removed within 20 min, while the total organic carbon (TOC) removal efficiency attained 9.1% in 20 min, and then reached 77.1% in 80 min under optimal conditions of 2 mg/min ozone dosage and 2 mA/cm(2) current density. TC was suspected to be oxidized into some four- and three-ring intermediates within 20 min, some two- and one-ring intermediates within 80 min, and eventually carboxylic acids, CO2 and H2O. The concentrations of NO3-, NO2- and NH4+ increased slightly in the first 20 min and then elevated significantly from 20 to 80 min, indicating an enhanced denitrification rate via electrochemical oxidation. Besides, the bioluminescence inhibition ratio exhibited a slight decrease from 54.5% to 50.6% in the first 20 min and then significantly decreased to 14.5% in 80 min, suggesting an augmented toxicity reduction simultaneously by the coupled technology. Overall, the O-3-REM coupled process demonstrated higher TC degradation and TOC removal efficiencies, enhanced toxicity-reduction capability, and lower energy consumption for TC removal compared to individual O-3 or Ti4O7 REM processes. By comprehensively analyzing the performance, mechanism and energy consumption of TC removal by the O-3-REM coupled process, our research provides insights into the application potential of the coupled process to efficiently eliminate the amount and toxicity of various pharmaceuticals from wastewater.

关键词： MgFe2O4 nanoparticles   Alcohol combustion   Reactive red   Adsorption kinetics   Adsorption isotherm  

摘要： Magnetic MgFe2O4 nanoparticles were prepared successfully via a facile alcohol combustion process and applied to remove the reactive red (RR) from aqueous solution. Characterizations of the as-prepared MgFe2O4 nanoparticles were performed by the scanning electron microscopy (SEM), the transmission electron microscope (TEM), the X-ray diffraction (XRD), the vibrating sample magnetometer (VSM), and the Brunauer-Emmett-Teller (BET) measurement. The adsorption characteristics of RR onto MgFe2O4 nanoparticles at room temperature were investigated. Compared with the pseudo-first-order and intraparticle diffusion model, the pseudo-second-order kinetic model could be applied to evaluate the adsorption performance of RR onto MgFe2O4 nanoparticles in a range of initial concentration of 100-400 mg/L. Based on the values of the correlation coefficients, the equilibrium experimental data related to the adsorption of RR showed that the adsorption performance followed the Langmuir isotherm model with maximum adsorption capacity of 119.07 mg/g. The obtained results implied that the adsorption mechanism of RR onto MgFe2O4 nanoparticles at room temperature was the monolayer adsorption. Magnetic MgFe2O4 nanoparticles were prepared via the facile alcohol combustion process, and the magnetic MgFe2O4 nanoparticles were applied to remove the reactive red (RR) from aqueous solution, the adsorption kinetics and adsorption isothermals of RR onto MgFe2O4 nanoparticles at room temperature were investigated. [GRAPHICS] Highlights. MgFe2O4 nanoparticles were prepared via the facile alcohol combustion process.. The pseudo-second-order kinetics model can explain the adsorption process of RR onto them.. The adsorption isotherm of RR onto them at room temperature conformed to Langmuir model.