关键词： Nano-copper oxide   Sonoelectrochemical process   Solid state kinetics   Ultrasonic irradiation   Environmental-friendly method  

摘要： The main objective of this study was the development of a simple, clean, and industrial applicable electrochemical process for production of high pure nano-copper oxides from mining and industrial resources (e.g., ore, spent, slag and wastewater). To conduct the proposed process, a special set up containing an electrochemical cell in an ultrasonic system (28 kHz and 160 W) was proposed. Accordingly, using this set up and applying appropriate voltage (approximate to 5 V) at 25 degrees C, in the presence of N-2 gas, the simultaneous anode dissolution and nano-copper oxides formation (approximate to 24 nm) can be occurred, rapidly (less than 45 min). Then, the effect of N-2 gas and free radicals generated by ultrasonic irradiation was studied. The results showed, in the absence of ultrasonic irradiation and N-2, an increase of electrolyte pH from 6.42 to 10.92, a decrease of electrolyte Eh from 285 mV to -1.14 V, and formation of copper nanoparticles. While, in the presence of ultrasonic and N-2, the CuO nano particles were formed due to presence of H2O2 generated by interaction of free radicals. Moreover, a novel method for kinetics modeling of nanoparticles agglomeration was proposed according to distributed activation energy model and Arrhenius parameters variation. The results showed that, in the absence of ultrasonic irradiation, the nanoparticle agglomerates were firstly formed (interface controlled mechanism) and then, the diffusion of nanoparticle agglomerates was occurred (diffusion controlled mechanism). Therefore, the control of nanoparticles size and shape may be impossible without surfactant. Also, in the presence of ultrasonic irradiation, the whole of agglomeration process followed interface controlled mechanism. Therefore, using ultrasonic irradiation, the nanoparticles shape and size don't change due to prevention of agglomerates diffusion.

关键词： Polypyrrole   Q235 steel   Electrochemical deposition   Anti-corrosion performance  

摘要： The polypyrrole (abbr. PPy) film was deposited on the surface of Q235 steel by potentiostatic deposition at different constant potentials (0.75 V, 0.85 V, 0.95 V, 1.05 V and 1.15 V, respectively). Through comprehensive characterizations and investigations by FT-IR, SEM, EDX, XRD and I-t curves, it is proved that the deposition potential obviously affects the composition of the deposited PPy film by synchronously adjusting the dissolution rate of ferrous oxalate passivation layer and the polymerization and deposition rate of PPy. At the deposition potential of 0.75 or 1.15 V, FeC2O4 was embedded in the deposited films because of the mismatch of the above two types of rates. While the deposition potential was designed to be 0.85, 0.95 or 1.05 V, FeC2O4 did not exist in the deposited PPy films for the good rate match of passivation layer's dissolution and PPy's polymerization and deposition. On the other hand, deposition potential also affects the morphology of the as-deposited PPy films. Among the back three samples which without FeC2O4 in the film, PPy-Q235-0.95 has the smallest aggregate size and the highest film density. The results of anti-corrosion performance study through potentiodynamic polarization curve, electrochemical impedance spectroscopy indicates that PPy-Q235 series samples have superior anti-corrosion properties than bare Q235, and PPy-Q235 samples without FeC2O4 in the film have better anti-corrosion performance than those with FeC2O4 in. Moreover, PPy-Q235-0.95 shows the best anti-corrosion behaviors (with the maximum E-corr, the minimum I-corr and CR, as well as with the maximum R-ct, R-po, R-ox and the minimum C-dl, Q(po), C-ox) in this paper, which is mainly resulted from its smallest aggregate size and highest film density.

关键词： 能源生产   电气化   消费   进程   能源体系   政府工作   传统产业   习近平  

摘要： 习近平总书记在党的十九大报告中指出,＂推进能源生产和消费革命,构建清洁低碳、安全高效的能源体系＂,为我国能源发展指明了方向。今年的政府工作报告提出,发展壮大新动能,运用新技术、新业态、新模式,大力改造提升传统产业。贯彻落实好这些重要部署,破解能源发展难题,需要坚持以电力为中心,大力推进再电气化。

关键词： 清洁能源   电气化   进程   助推   特高压   电网  

摘要： 两会期间，来自电网的全国两会代表、委员围绕特高压、清洁能源消纳、再电气化、乡村振兴、服务人民美好生活等重大议题建言献策。

关键词： Simultaneous electroleaching-electrodeposition   Electro-oxidation   Silver   Thiosulfate   Recycling  

摘要： The simultaneous electroleaching-electrodeposition of silver was studied systematically to develop an alternate process for the recovery of metallic silver. The system was assessed employing electrochemical and micro structural characterization techniques in a thiosulfate-ammonia medium. The electrochemical studies revealed the dependence of silver electroleaching rate in thiosulfate-ammonia solutions on different processes controlled by anodic potential. At the anodic potential below 200 mV(SHE), the silver is electro-oxidized and complexed by the applied potential and thiosulfate, respectively. Increasing the potential up to 445 mV(SHE), the thiosulfate is oxidized and the silver leaching current is decreased due to the diffusional control of the leaching. It was also found that the sulfite species formed from the thiosulfate decomposition can leach small amounts of metallic silver. Finally, at potentials from 695 to 795 mV(SHE), the thiosulfate is further decomposed and a silver sulfide film is generated which inhibits the silver dissolution. The simultaneous electroleaching-electrodeposition of silver was also studied in an electrolytic cell with graphite electrodes at room temperature. The results showed that a 74% of silver can be recovered at a low applied current density of 0.066 mA/cm(2) with a negligible thiosulfate decomposition and a current efficiency of 76.54%. On the other hand, when the current is increased the silver recovery and current efficiency is decreased, due to the oxidative decomposition of thiosulfate which promotes the formation of silver sulfide. These results are corroborated by the X-ray diffraction and SEM-EDS analyses.

关键词： Steel pipeline   soil   cathodic protection   stray current corrosion   anodic transient  

摘要： The steel/soil interface on cathodically protected pipeline steel has been investigated using electrochemical polarisation measurements and electrochemical impedance spectroscopy, to add more insights into the electrochemical processes occurring at the interface. A critical electrode potential (CEP) was found that divides the steel corrosion reaction kinetics into two regions. When the electrode potential is below this critical value, the steel surface has a large impedance value, indicating much slower corrosion kinetics than when the electrode potential is more positive than the CEP value. This critical value is found to be related to pitting potential determined by potentiodynamic polarisation measurements. The CEP could be affected by the CP condition and environmental, including the CP potential and the soil moisture content. At a more negative CP potential, the CEP was found to be nobler;while at the same CP potential but in the soil with a higher moisture content, the CEP became more negative. The impact of the CP potential and soil moisture level on the CEP value is explained by local soil pH effects on steel passivity.

关键词： Hydrogen   Sulfur-iodine cycle   Electrochemical Bunsen reaction   Electrochemical cell (EC)   Flow channel   Pressure drop  

摘要： Renewable hydrogen production through sulfur-iodine (SI) cycle is energy efficient and environmentally friendly. Electrochemical cell (EC) has recently been proposed to carry out the Bunsen reaction in the cycle. Existing studies on the EC are limited only to time-consuming experiments whereas cell performance with respect to flow channel is very few. In this study, numerical study is conducted for determining the impact of flow channel on the EC performance of electrochemical Bunsen reaction. Five different configurations of flow channel are physically modelled. A three dimensional, steady state and laminar flow through EC is simulated by solving the governing equations, and show good agreement with experimental data at low current density. It is found that the flow field, local current and potential of serpentine, straight parallel and spiral tubular flow channels distribute almost uniformly, except the significant vortex regions and high resistance at the square bends of straight parallel channel due to the sudden geometric changes. The flow maldistribution in Z-type and U-type parallel flow channels makes them unsuitable for EC. The straight parallel flow channel is found to be optimal due to its low pressure drop as well as low electric power input, followed by serpentine and spiral tubular patterns. The simulation concerning flow channels design favors improving EC performance and the thermal efficiency of SI cycle.

关键词： copper electrodeposition   through silicon via   ultrasound  

摘要： As one of the key technologies in 3D packaging, through silicon via (TSV) interconnection technology has become a focus recently. In this paper, an electrodeposition method for TSV filling with the assistance of ultrasound and additives are introduced. Two important parameters i.e. current density and ultrasonic power are studied for TSV filling process and electrochemical properties. It is found that ultrasound can improve the quality of TSV-filling and change the TSV-filling mode. The experimental results also indicate that the filling rate enhances more significantly with decreasing current density under ultrasonic conditions than under silent conditions. In addition, according to the voltammetry curve, the increase of ultrasonic power can significantly increase the current density of cupric reduction, and decrease the thickness of diffusion layer. So that the reduction speed of copper ions is accelerated, resulting in a higher TSV-filling rate.

关键词： Photoluminescence   Chemical elements   Scanning electron microscopy   Etching  

摘要： In this work, the electrochemical etching of p-type silicon was performed in aqueous ethanol-surfactant solutions and the dependence of morphology and luminescent properties of porous silicon with respect to the etching parameters and silicon resistivities have been studied. The obtained porous silicon structures have been studied using various characterisation techniques such as SEM (Scanning Electron Microscopy) and Photoluminescence (PL) spectroscopy.

关键词： ELECTROCHEMICAL analysis   ISOMERIZATION kinetics   DIHYDROPYRENES   PYRIDINIUM compounds   PHOTOCHROMIC materials   NUCLEAR magnetic resonance spectroscopy  

摘要： The electrochemical control of the isomerization process of a photo-switchable dimethyldihydropyrene (DHP) derivative has been investigated. Spectro-electrochemical experiments clearly evidence that the substitution of the DHP core by electron-withdrawing entities can be used to control the opening/closing process.