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To mitigate air pollution problem, the government has been planning to build more liquefied petroleum gas stations to motivate drivers to use liquefied petroleum gas vehicles in Taiwan. Such facility allocation problem is a multi-objective optimization process considering spatial variation in the need of refueling. This study presents a stochastic multi-objective optimization model for liquefied petroleum gas station allocation (SMOMLSA) that integrates a nondominated sorting genetic algorithm II with a Monte Carlo simulation to optimally allocate liquefied petroleum gas stations according to three trade-off objectives, including investment performance, energy conversion, and business opportunity. Monte Carlo simulation procedure generates the starting location of a taxicab car in need of refueling in the spatial grid based on a probability distribution. Nondominated sorting genetic algorithm II resolves the station location problem with these multi-objectives. The SMOMLSA was validated by conducting a real-world case study. Result depicts that the SMOMLSA can provide information on the optimal allocation of liquefied petroleum gas stations for minimizing construction costs, minimizing average refueling distance for vehicles, and maximizing potential customers.

Herein, the nanostructured polypyrrole-coated MnO2 nanofibers growth on carbon cloth (PPy-MnO2-CC) to serve as the electrodes used in conjunction with a quasi-ionic liquid-based polymer gel electrolyte (urea-LiClO4-PVA) for solid-state symmetric supercapacitors (SSCs). The resultant PPy-MnO2-CC solid-state SSCs exhibited a high specific capacitance of 270 F/g at 1.0 A/g in a stable and wide potential window of 2.1 V with a high energy/power density (165.3 Wh/kg at 1.0 kW/kg and 21.0 kW/kg at 86.4 Wh/kg) along with great cycling stability (capacitance retention of 92.1% retention after 3000 cycles) and rate capability (141 F/g at 20 A/g), exceeding most of the previously reported SSCs. The outstanding performance of the studied 2.1 V PPy-MnO2-CC flexible SSCs could be attributed to the nanostructured PPy-coated MnO2 composite electrode and the urea-LiClO4-PVA polymer gel electrolyte design. In addition, the PPy-MnO2-CC solid-state SSCs could effectively retain their electrochemical performance at various bending angles, demonstrating their huge potential as power sources for flexible and lightweight electronic devices. This work offers an easy way to design and achieve light weight and high-performance SSCs with enhanced energy/power density.

The effects of both climate change and the geographic location of Taiwan have influenced the perceived variability of river flow and increased uncertainty and complexity in the management of river basins. In this study, a genetic algorithm (GA) optimizer was integrated into a stochastic river basin model to develop a stochastic optimization river basin management model (SORBMM). Firstly, the flow probability density function was determined through statistical analysis of the hydrological data. A Monte Carlo simulation was then conducted to evaluate the effect of flow variability, and a GA was implemented to obtain an optimal river pollution reduction strategy. A true case involving multi-objective management of a river basin under conditions of high spatiotemporal flow variation was tested to demonstrate the feasibility of the SORBMM. The results revealed that a reduction in pollution removal would lead to higher risks for river basin management due to the dilution effect in the river downstream and the objective of lowering pollution removal costs.

A 3D network composed of V2O5 nanofibers was manufactured on a novel conductive printing paper [urea-LiClO4-PVA (ULP) deep eutectic solvent gel-doped graphite/printing paper, U-paper] for use as electrodes linked with a ULP neutral gel electrolyte for 3D network V2O5 wearable symmetric pseudocapacitors (WSSCs). The function of the ULP gel is not only that it can be doped into the conductive ink to decrease the resistance of the conductive printing paper but also that it increases the stability of V2O5-based electrodes. Moreover, 3D network V2O5 WSSCs containing the ULP gel can support high operating voltages of 4.0 V with great specific capacitance (160 F/g) and offer a high energy density (355 W h/kg at 0.2 kW/kg). The 3D network V2O5 WSSCs exhibit a superior cycling stability/durability after 5000 cycles (capacitance retention of ∼91%). Operando X-ray absorption spectroscopy experiments show the reversibility and pseudocapacitive properties of V2O5 from the ULP gel and offer the information of the oxidation states of vanadium during charge-discharge cycles. The 3D network V2O5 WSSCs with the ULP gel electrolyte show great potential prospective candidates for smarter 3D wearable energy-storage devices and Internet-of-Things applications.

Polymer gel electrolytes have shown potential for enhancing operation stability and cycle longevity in energy storage devices; however, their use in osmotic power conversion remains unexplored, because one would expect reduced ionic conductance at the nanoscale, which in turn can impact their performance output. Here we report the first polymer gel electrolyte-based osmotic power generator by introducing polyvinyl alcohol (PVA) as a solid matrix. We present the experimental evidence showing that with the PVA gel electrolyte, the ion transport and osmotic power can be enhanced under conditions in which the electric double layer overlap effect in nanochannels is significant; thus, a substantial increase of the power output as high as nearly two times can be achieved as compared to the corresponding aqueous electrolytes. The observations are explained by the adsorption of excess counterions onto PVA confined at the nanoscale, supported by our modeling performed using the modified Poisson and Nernst–Planck equations by considering a charged PVA layer in a nanochannel. The system presented offers a new avenue toward the exploitation of high-performance and safe osmotic power generators.

In this work, we successfully fabricated 3D network vanadium oxide (VOx) and manganese oxide (MnOx) nanofibers on conductive paper (PVA–acetamide–LiClO4-graphite/paper, PGP) as electrodes linked with an eco-friendly PVA–acetamide–LiClO4 (PAL) deep eutectic solvent-based gel electrolyte for high-voltage wearable asymmetric supercapacitors (HVWASCs). An ecologically compatible deep eutectic solvent-based electrolyte with self-supporting electroactive species has been generally accepted as a unique type of cost-effective and green electrolyte that possibly involves a bulk concentration of the electroactive species and a large working potential window, thereby achieving a high performance. The HVWASCs are able to work with a large operating voltage of 4.2 V, and supply outstanding energy and power densities (245 W hkg−1 at 0.18 W kg−1 and 95.3 kW kg−1 at 98 W h kg−1). The HVWASCs demonstrate remarkable cycling stability and durability after 6000 cycles, including bending and twisting (capacitance retention of 91.5%). The HVWASCs are a superior prospective candidate for wearable/flexible electronic devices and Internet of Things (IoT) applications.

To meet future demands for cutting-edge wearable electronics, flexible supercapacitors must possess many features, such as eco-friendly processing, aesthetic appeal and no health hazards, in addition to have lightweight, robust and excellent cycling stability. We proposed a biomimetic and scalable method to fabricate an all-solid-state flexible supercapacitor (assFSC) using bioinspired clay/polymer nanocomposites and electroplated manganese oxide as electrode materials and a gel electrolyte. Experimental results from X-ray techniques (tomography, scattering and diffraction) showed that the electrode’s structure features a 3D ant-nest-like framework composed of 2D nacre-like clay nanosheets, i.e. hierarchical layers-within-networks structure, which is formed via water-evaporation induced self-organization. The shapeable electrodes made by a molding process could, therefore, be used to meet the demands for fashionable, wearable electronics. Accordingly, the structural electrodes exhibit high tensile strength of 62 MPa, Young’s modulus of 4.4 GPa, and torsional strength of 165 MPa. Under a large operating potential of 4.0 V, the assFSC exhibited ultrahigh energy density (233.3 W h kg−1 at 2 kW kg−1), ultrahigh power density (125 kW kg−1 at 55.5 W h kg−1), and outstanding static cyclability (

The impurity level, surface functional group concentration, and specific surface area of activated carbons (ACs) are manipulated via acid rinsing, post heat treatment, and activation time, respectively. The effects of these factors on the electrode gravimetric/volumetric capacitances, leakage current, and gas evolution amount in 1 M triethylmethylammonium tetrafluoroborate/propylene carbonate electrolyte are systematically investigated. The impurity and surface functional groups do not significantly influence the electrode capacitances (regardless of charge–discharge rates), but increase the leakage current and gas evolution amount of the constructed supercapacitors. Increasing the specific surface area of ACs increases the capacitor gravimetric energy density and power density, but decreases the corresponding volumetric performance. The cyclic stability of various ACs is evaluated at 25 and 70 °C. Property variations of the electrodes upon cycling are examined using scanning electron microscopy and electrochemical impedance spectroscopy.

A 3D network composed of V

The goal of this study was to examine the effects of lipid composition on physicochemical characteristics of hydrogenated soybean lecithin (HL)/d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) dispersions using dynamic light scattering, transmission electron microscopy, differential scanning calorimetry, and fluorescence polarization spectroscopy. Our results showed that HL-rich nano-dispersions exhibited larger size, narrower size distribution, higher negative zeta potential, more obvious phase transition regions, and lower membrane fluidity than did the TPGS-rich ones. The membrane packing order, intermolecular attraction interaction, and molecular cooperativity in the phase transition region of the HL dispersions could be reduced by the incorporation of a large amount of TPGS. Furthermore, chemical stability, a drug release profile, and free radical-scavenging capacity of HL/TPGS nano-dispersions encapsulating black soybean seed coat extract (BE) were analyzed. HL/TPGS nano-dispersions improved the stability and radical-scavenging capacity of phytochemicals, such as BE. Nano-dispersions with the molar ratio of HL/TPGS = 9/1 exhibited good storage stability, a slow BE release rate, good free radical-scavenging capacity, and high in vitro biocompatibility; thus, they could be a high-potential vehicle for carrying active herbal agents.

Population increase and urbanization have considerably altered land-use patterns in central Taiwan. To determine the effects of urbanization in central Taiwan, this study used a buffer analysis, hierarchical cluster analysis, and multidimensional scaling to identify the relationship between egret nesting sites and land-use changes during the agricultural, industrial, and service economy periods of the urbanization process. The results demonstrate that built-up land increased markedly over time in central Taiwan, especially within the 1-km circle buffer of egret nesting sites. A longer interquartile range in the service economy period indicates that the distribution of cultivated land near egret nesting sites was relatively fragmented. The types of land-use with similar features were clustered into the same group using hierarchical cluster analysis and multidimensional scaling. The group classification results of the hierarchical cluster analysis and multidimensional scaling were consistent with the results of the Pearson correlation analyses. The horizontal axis in the multidimensional scaling dendrogram may represent the gradient from the main to minor food source areas. Hierarchical cluster analysis and multidimensional scaling could be used for initial identification of urbanization processes. Furthermore, egrets in central Taiwan adapted to urbanization and fed on discarded human food during Taiwan’s service economy period.

Large-area Co(OH)2-based supercapacitor electrodes composed of nanotube arrays grown on a 3D nickel-foam (CONTA) electrode and sucker-like nanoporous films grown on a 3D nickel-foam (COSNP) electrode were prepared with a facile electrochemical method for applications in energy storage. These nanoporous Co(OH)2 electrodes were fabricated with the codeposition of Cu/Ni film on the nickel foam, then etching of Cu from the Cu/Ni layer to form Ni nanotube arrays and sucker-like Ni nanoporous layers, and further cathodic deposition of Co(OH)2 on the prepared nanoporous Ni substrates. The CONTA and COSNP electrodes exhibited specific capacitances of 2500 and 2900 F/g in a voltage range of 0.65 V (capacitance of the substrates deducted from the total) at 1 A/g in a three electrode cell, respectively. The COSNP electrode demonstrated an excellent supercapacitive performance with specific capacitances 1100 F/g at 1 A/g and 850 F/g at 20 A/g in a voltage range of 1.2 V in a two electrode cell. The remarkable performance of COSNP electrodes correlated with a large conversion of the Co oxidation state during the charge/discharge cycling were examined by in situ X-ray absorption near edge structure (XANES).

With a simple electrochemical process, we prepared nano-architectured CuO electrodes with a 3D hierarchically porous structure and an excellent supercapacitive performance. These nano-architectured CuO electrodes were processed through co-deposition of a Ni–Cu layer on Ni foam, selective etching of Cu from the Ni–Cu film (leaving tentacle-like nanoporous Ni), and anodic deposition of CuO nanoribbons (NRs) on the tentacle-like nanoporous Ni/Ni foam substrate. Because of its unique nano-architecture, the prepared CuO nanoribbon-on-Ni-nanoporous/Ni foam (CNRNP) electrode shows exceptional performance of energy storage relative to a conventional version of the electrode. The CNRNP electrode has also a superior kinetic performance relative to CuO nanoflake-on-Ni foam (CNFNF) and flake-like CuO (FLC) electrodes. Besides its excellent cyclic stability, an exceptionally large specific capacitance of 880 and 800 F g−1 (deducting the substrate capacitance from the total) for the CNRNP electrode is obtained at scan rates of 10 and 200 mV s−1, respectively. The excellent pseudocapacitive characteristics of CNRNP electrodes associated with the variation of the Cu oxidation state during charge and discharge cycles were elucidated with in situ X-ray absorption near-edge structure (XANES) spectra.

Here we report a simple, scalable, and low-cost method to enhance the electrochemical properties of Mn oxide electrodes for highly efficient and flexible symmetrical supercapacitors. The method involving printing on a printer, pencil-drawing, and electrodeposition is established to fabricate Mn oxide/Ni-nanotube/graphite/paper hybrid electrodes operating with a low-cost, novel urea-LiClO

This paper describes a fabrication protocol for a dipole-assisted solid phase extraction (SPE) microchip available for trace metal analysis in water samples. A brief overview of the evolution of chip-based SPE techniques is provided. This is followed by an introduction to specific polymeric materials and their role in SPE. To develop an innovative dipole-assisted SPE technique, a chlorine (Cl)-containing SPE functionality was implanted into a poly(methyl methacrylate) (PMMA) microchip. Herein, diverse analytical techniques including contact angle analysis, Raman spectroscopic analysis, and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis were employed to validate the utility of the implantation protocol of the C-Cl moieties on the PMMA. The analytical results of the X-ray absorption near-edge structure (XANES) analysis also demonstrated the feasibility of the Cl-containing PMMA used as an extraction medium by virtue of the dipole-ion interactions between the highly electronegative C-Cl moieties and the positively charged metal ions.

Vanadium-based oxides are prepared on graphite substrates by an anodic deposition technique. The plating bath is 0.2 M VOSO 4 solution with NaCH 3 COO addition. A scanning electron microscope and an X-ray diffractometer are used to characterize the deposits; the analyses indicate that the porous Na-doped V 2 O 5 electrodes with a nano-crystalline nature are obtained. Supercapacitor properties of the oxide electrodes are studied using cyclic voltammetry in KCl aqueous electrolyte. The data show that the deposited oxides can exhibit ideal capacitive behavior over a potential range of 1 V; the optimum specific capacitance is ∼180 F/g. A lower deposition potential leads to a higher porosity of the oxide, resulting in a better high-rate supercapacitor performance of the electrode.

An Al coating film, electrodeposited on a Mg alloy from aluminum chloride–1-ethyl-3-methylimidazolium chloride (AlCl 3 –EMIC) ionic liquid, effectively prevents the substrate from rapid corrosion in a hostile environment. The thickness of the Al film can be easily determined by controlling the total cathodic charge applied, because the current efficiency of the electrodeposition reaction is close to 100%. Heat treatment at 450 °C under an argon atmosphere for 10 min causes an inter-diffusion at the Al/Mg interface, optimizing the protective performance of the coating film. Prolonging heating leads to a Mg 17 Al 12 intermetallic phase and a Mg solid solution phase to be formed at the expense of the deposited Al film. This phase transformation gives rise to a degradation in the corrosion resistance of the Al-coated sample.

The corrosion properties of carbon steel (CS), 304 stainless steel (304 SS), and pure titanium (Ti) are first studied in aluminum chloride–1-ethyl-3-methylimidazolium chloride ionic liquid (IL). An active-to-passive transition behavior was clearly observed for CS. The 304 SS exhibited the best stability among the materials; no considerable corrosion was recognized even in this high-chloride environment. In contrast, although Ti resists corrosion in ambient environments, it was not passivated in the IL and became severely corroded under an anodic applied potential. The material corrosion behaviors and mechanisms in the non-aqueous, low-oxygen, and high-halogen-containing IL are completely different from those in traditional aqueous solutions. Keywords: Ionic liquid, Corrosion behavior, Titanium, Stainless steel, Carbon steel

Charge storage mechanisms of electrodeposited MnO2 in various aprotic ionic liquids (ILs) are studied using in situ X-ray absorption spectroscopy (XAS). The analytical results show that a unique thiocyanate (SCN−) anion can reversibly insert/desert into/from the tunnels between the [MnO6] octahedral subunits depending on the applied potential. This process charge compensates the Mn3+/Mn4+ redox transition upon charging–discharging and thus contributes to an ideal pseudocapacitive behavior of the MnO2 electrode. The present work would open up a route for developing a novel oxide-based supercapacitor, with high cell-voltage, high thermal stability, and high safety, incorporating IL electrolytes.

The voltammetric behavior of N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid (BMP-TFSI) containing Cu(I), Mn(II), or mixtures of Cu(I) and Mn(II) as well as the electrodeposition of copper–manganese alloy coatings (Cu–Mn alloy coatings) was studied at 323 K. The Cu(I) and Mn(II) species required to prepare these coatings were introduced into the BMP-TFSI by anodic dissolution of the relevant metallic electrodes. Electrodeposits of Cu, Mn, and Cu–Mn with various contents of Mn can be obtained by controlled-potential electrolysis. It was found that the compositions and surface morphology of the electrodeposited Cu–Mn alloy coatings depend on the deposition potentials and the concentration ratio of [Cu(I)]/[Mn(II)] in BMP-TFSI. The Cu–Mn alloy coatings obtained in this study were compact and adherent. They did not show any significant X-ray diffraction signal that could be assigned to the crystalline structures of Cu, Mn, or Cu–Mn alloys. In the aqueous solution containing 0.1 M NaCl, the Cu–Mn alloy coatings demonstrated passive behavior—no continuous oxidation was observed. However, a significant oxidation current was observed at the electrodes deposited with Cu or Mn.

The electrochemical behavior of anodically deposited manganese oxide was studied in pyrrolidinium formate (P-HCOO), 1-butyl-3-methylimidazolium hexafluorophosphate (BMI-PF6), and 1-ethyl-3-methylimidazolium thiocyanate (EMI-SCN) ionic liquids (ILs). The experimental data indicate that the Mn oxide electrode showed ideal pseudocapacitive performance in aprotic EMI-SCN IL. In a potential window of approximately 1.5 V, the oxide specific capacitance, evaluated using cyclic voltammetry and chronopotentiometry, was about 55 F/g. The electrochemical energy storage reaction was examined using X-ray photoelectron spectroscopy (XPS). It was confirmed that the SCN- anions, instead of the EMI+ cations, were the primary working species that can become incorporated into the oxide and thus compensate the Mn3+/Mn4+ valent state variation upon the charge-discharge process. According to the analytical results, a pseudocapacitive mechanism of Mn oxide in the SCN- based aprotic IL was proposed.

Pseudocapacitive characteristics of manganese (Mn) oxide were recognized in aprotic ionic liquid (IL), namely, butylmethylpyrrolidinium−dicyanamide (BMP−DCA), within a potential window of 3 V. The electrochemical energy storage mechanism was examined using X-ray photoelectron spectroscopy and in situ X-ray absorption spectroscopy. It was confirmed that the DCA− anions, instead of the bigger BMP+ cations, were the working species that compensate the Mn valent state variation upon charging and discharging in the IL electrolyte. During oxidation of the Mn oxide electrode, to keep the charges balanced, the quasi-linear DCA− anions were inserted into the tunnels between the MnO6 octahedral units, expanding the structural framework. Importantly, a highly reversible process was observed during the subsequent reduction step. XPS depth profiling analyses showed that the electrochemical reaction thickness was approximately 50 nm.

Manganese (Mn) oxide was prepared by anodizing metallic Mn film that was electrodeposited in n-butylmethylpyrrolidinium bis(trifluoromethylsulfony)imide (BMP–NTf2) ionic liquid. Different anodization courses, namely potentiostatic and cyclic voltammetric methods, led to variations in physical and chemical characteristics of the Mn oxides, and therefore in their pseudocapacitive performance. Evolution of the microstructure, residual weight, and chemical state of the Mn oxides with the charge–discharge cycling number was studied using a scanning electron microscope (SEM), an atomic absorption spectroscope, and an X-ray photoelectron spectroscope, respectively. The analytical results indicate that the electrochemical stability of Mn oxide is mainly determined by its microstructure; the more fibrous (or porous) oxide had a greater durability against cyclic charge–discharge. Moreover, the chemically hydrous state was found to be the most crucial factor that governed the mass specific capacitance of Mn oxide.

Extraction of Cu(II) from neutral aqueous solutions with the hydrophobic room-temperature ionic liquid (IL) N -butyl- N -methylpyrrolidinium bis((trifluoromethyl)sulfonyl)imide (BMP-TFSI) in the presence of the pyridine-based ionophore N 1 , N 1 , N 4 , N 4 -tetrakis(2-(pyridin-2-yl)ethyl)butane-1,4-diamine (C 4 N 2 Py 4 ) is demonstrated in this study. Although the distribution coefficients, D M , of Cu(II) extraction depend on the concentration of Cu(II) in aqueous solutions, all values were higher than 200, indicating extremely high extraction efficiency. Based on spectrophotometric, electrochemical, and X-ray crystallography studies, the coordination number of the C 4 N 2 Py 4 -coordinated Cu(II) ions was determined as 2. The voltammetric behavior of Cu(I), Cu(II), and their C 4 N 2 Py 4 complex ions were also studied. The recovery of Cu from the IL was conducted by washing the IL phase containing the extracted Cu(II) complex with an acidic aqueous phase or by controlled-potential electrolysis. The IL containing C 4 N 2 Py 4 was employed for two complete rounds and a decrease in extraction efficiency was only observed when higher concentration of Cu(II) was used.

The electrodeposition behavior of nickel was investigated at glassy carbon and polycrystalline copper electrodes in the 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA) room-temperature ionic liquid. Amperometric titration experiments suggest that Ni(II) reacted with DCA − anions forming [Ni(DCA) 4 ] 2− complex anion, which could be reduced to nickel metal via a single-step electron transfer process. However, the anodic dissolution of the nickel deposits was sluggish. The electrodeposition of nickel proceeds via three-dimensional progressive nucleation with diffusion-controlled growth on both glassy and copper substrates. Scanning electron microscopy images of the nickel deposits indicated that the morphology of the nickel electrodeposits is dependent on the deposition potential. Atomic force microscopy topography illustrated that the roughness of the nickel-deposited surface increased with decreasing deposition potential. The crystalline nature of the nickel deposits was revealed by powder X-ray diffraction spectroscopy results which indicated that the grains size of the nickel deposits decreased with decreasing deposition potential.

Electrodeposition of a metallic Al layer on a Mg alloy from a Lewis acidic Al chloride–1-ethyl-3-methylimidazolium chloride (EMIC) ionic liquid has been carried out at room temperature. The effects of the AlCl3 to EMIC molar ratio, in the range from 50%–50% to 60%–40%, on the electrodeposition characteristics were investigated. Scanning electron microscopy, X-ray energy dispersive spectroscopy, and X-ray diffractometry were used to examine the surface morphology, the chemical composition, and the crystal structure of the deposited layers prepared in the ionic liquids with different AlCl3 to EMIC ratios. The improvement of corrosion resistance of a Mg alloy to the Al surface coating was also evaluated by means of various electrochemical methods. The electrochemical impedance spectroscopic data indicated that while a bare Mg alloy had a polarisation resistance of only 470 Ω cm2 in 3˙5 wt-% NaCl solution, the Al coated sample deposited in the ionic liquid with 60%AlCl3 showed a resistance as high as ...

Electrodeposition of manganese (Mn) in butylmethylpyrrolidinium bis(trifluoromethylsulfony)imide (BMP–NTf2) ionic liquid is demonstrated in this study. Crystal structures and surface morphologies of the Mn films deposited at various potentials (from −1.8 V to −2.2 V) and temperatures (from 50 °C to 110 °C) were examined with an X-ray diffractometer (XRD) and a scanning electron microscope (SEM), respectively. Experimental results indicate that the deposited Mn films were amorphous in nature; however, their morphologies strongly depended on the deposition conditions. After being anodized in Na2SO4 solution, the deposited Mn was transformed to Mn oxide. Electrochemical properties of the Mn oxides were evaluated using cyclic voltammetry (CV). It was confirmed that the different Mn deposition conditions caused the variations in pseudocapacitive performance of the oxide electrodes. The oxide (∼0.1 mg) anodized from the Mn deposited at −1.8 V and 50 °C had the highest specific capacitance of 402 F/g measured at a CV scan rate of 5 mV/s. Its capacitance retained ratio after 500 CV testing cycles was as high as 94%.

A novel electrochemical route to prepare the Mn oxide with ideal pseudocapacitive performance is successfully proposed in this study. In n-butylmethylpyrrolidinium bis(trifluoromethylsulfony)imide (BMP–NTf2) ionic liquid, a nanostructured and amorphous Mn film could be electrodeposited on a Ni substrate. The metallic Mn films were then anodized in Na2SO4 aqueous solution by the potentiostatic, galvanostatic, and cyclic voltammetric methods and transformed to Mn oxides. It was confirmed that the different anodization courses would cause variations in the material characteristics of the prepared Mn oxides and therefore in their pseudocapacitive performance. The Mn oxide anodized by the cyclic voltammetric method showed the most promising specific capacitance of 402 F g−1; moreover, its capacitance retained ratio after 500 charge–discharge cycles was as high as 94%.

Electrodeposition of Al, Mn, Ni, Zn, Sn, and Cu are successfully demonstrnated in the ionic liquids (ILs) composed of 1-methyl-3-alkylimidazolium or N-methyl-N-alkylpyrrolidinium cations with dicyanamide (DCA) anions. The DCA-based room-temperature ILs exhibit lower viscosities than those ILs based on BF 4 - , PF 6 - , and bis(trifluoromethylsulfonyl)imide (TFSI) anions. While most of the metal chlorides are insoluble in the BF 4 - , PF 6 - , and TFSI-based ILs, they exhibit good solubility in DCA-based ILs due to the strong complexing ability of DCA toward the transition metal ions. It is possible to alter the regular reduction sequence for particular metal ions in the DCA-based ILs.

The electrochemistry of manganese was investigated at solid disk electrodes in the hydrophobic room-temperature ionic liquid butylmethylpyrrolidinium bis((trifluoromethyl)sulfonyl)imide (BuMePy-TFSI) by using staircase cyclic voltammetry and chronoamperometry. The Mn(II) species was introduced into the ionic liquid by anodic dissolution of the metallic manganese electrode. The reduction of Mn(II) ions at tungsten and platinum electrodes accompanies with nucleation mechanism and the coupled oxidation wave encounters kinetic hindrance that results in incomplete reoxidation of Mn electrodeposits. The density and absolute viscosity of BuMePy-TFSI were measured over a temperature range from 301.0 to 348.0 K. A polynomial equation describing the temperature dependence of the density is presented. The viscosity exhibits the Arrhenius temperature dependence and the relevant equation is provided. The manganese coatings were prepared by electrodeposition at several substrates. The surface morphology and X-ray diffraction patterns of these deposits were studied by scanning electron microscopy and powder X-ray diffraction spectroscopy, respectively. The as-electrodeposited manganese coatings were amorphous; however, α-phase manganese was observed after the deposits were annealed under 723 K for 1 day.

Two room temperature ionic liquids based on the bis ((trifluoromethyl)sulfonyl)-imide anion (TFSI anion), the tributylmethylammonium-TFSI (Bu3MeN-TFSI) and the butylmethylpyrrolidinium-TFSI (BuMePy-TFSI), have been prepared for the electrochemical study of Li+/Li redox couple, the electrodeposition of Mn, Zn-Mn alloys and Cu-Mn alloys, and the extraction of Cu(II) ions from aqueous solutions, respectively. The best coulombic efficiency of Li+/Li couple is 97%. Mn(II), Zn(II) and Cu(I) species were introduced into the Bu3MeN-TFSI or BuMePy-TFSI by the anodic dissolution of the respective metallic electrodes. Coatings containing Mn, Zn, Cu, Zn-Mn or Cu-Mn can be obtained by controlled-potential electrolysis. The current efficiencies of Mn electrodeposition in either ionic liquid approach 100%. The Zn-Mn and Cu-Mn alloy deposits obtained in this study were compact and adherent. The surface morphology of these deposits depended on the Mn/Zn and Mn/Cu ratio, respectively. The BuMePy-TFSI ionic liquid containing N,N,N',N'-tetrakis-(2-pyridin-2-yl-ethyl)- butane-1,4-diamine (N4Py2) exhibits good ability of extracting Cu(II) ions from aqueous solution. The electrochemical study revealed that both Cu(I) and Cu(II) can form strong coordinated compounds with N4Py2 because the redox potentials of Cu(II)/Cu(I) and Cu(I)/Cu(0) couples shift to much more negative values, respectively.

A dense and adhesive Al layer was successfully electrodeposited on a Mg alloy in aluminum chloride–1-ethyl-3-methylimidazolium chloride ionic liquid. The corrosion resistance of the uncoated and Al-coated samples was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization measurements in 3.5 wt% NaCl solution. It was confirmed that the protective Al layer significantly reduces the corrosion rate of the Mg alloy. However, the deposition potential was a crucial factor that governed the structure and therefore the protection capability of the Al layer. Keywords: Magnesium alloy, Corrosion, Electrodeposition, Al-coating, Ionic liquid

We employed a polymeric material, poly(methyl methacrylate) (PMMA), for fabricating a microdevice and then implanted the chlorine (Cl)-containing solid-phase extraction (SPE) functionality into the PMMA chip to develop an innovative on-chip dipole-assisted SPE technique. Instead of the ion-ion interactions utilized in on-chip SPE techniques, the dipole-ion interactions between the highly electronegative C-Cl moieties in the channel interior and the positively charged metal ions were employed to facilitate the on-chip SPE procedures. Furthermore, to avoid labor-intensive manual manipulation, a programmable valve manifold was designed as an interface combining the dipole-assisted SPE microchip and inductively coupled plasma-mass spectrometry (ICP-MS) to achieve the fully automated operation. Under the optimized operation conditions for the established system, the detection limits for each analyte ion were obtained based on three times the standard deviation of seven measurements of the blank eluent solution. The limits ranged from 3.48 to 20.68 ng L(-1), suggesting that this technique appears uniquely suited for determining the levels of heavy metal ions in natural water. Indeed, a series of validation procedures demonstrated that the developed method could be satisfactorily applied to the determination of trace heavy metals in natural water. Remarkably, the developed device was durable enough to be reused more than 160 times without any loss in its analytical performance. To the best of our knowledge, this is the first study reporting on the combination of a dipole-assisted SPE microchip and elemental analysis instrument for the online determination of trace heavy metal ions.

A continuous and adhesive Al layer was successfully electrodeposited on a Mg alloy in aluminum chloride/1-ethyl-3-methylimidazolium ionic liquid at room temperature. Surface morphology, crystal structure, and chemical composition of the deposit were examined with a scanning electron microscope, an X-ray diffractometer, and an X-ray energy dispersive spectroscope, respectively. The corrosion resistance of the Al-coated Mg alloy was also evaluated.

Due to the ligand property of the DCA anion, both CuCl and NiCl2 are soluble in 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA) ionic liquid. Cyclic voltammograms of Ni(II), Cu(I), and Ni(II)+Cu(I), respectively, in EMI-DCA were recorded on the glassy carbon electrode at 30°C. It is interesting to note that the thermodynamic deposition potentials of Ni and Cu are very close to each other. This is especially favorable for the electrodeposition of Ni-Cu alloys without any additive. The Ni-Cu alloys were electrodeposited using bulk controlled-potential electrolysis experiments. Energy-dispersive spectroscopy (EDS) data indicates that the composition of the Ni-Cu alloys not only depends on the deposition potential, but also on the Cu(I) and Ni(II) concentrations in the melt.

This work demonstrates that reticulate Sn film with nano-sized porosity can be obtained simply by direct electrodeposition of Sn nanowires without using any additive and template in a water and air stable ionic liquid, namely 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA) at 313 K.

With an ordered polystyrene (PS) template-assisted electrochemical approach we synthesized three-dimensional ordered macroporous (3DOM) Cu2O/Ni inverse opals as electrodes for supercapacitors. The 3DOM Cu2O/Ni electrodes display superior kinetic performance, and satisfactory rate capability and cycling performance.

The electronic structure and characteristics of Fe 3d valence states of iron-chalcogenide Fe(1.01)Se superconductors under pressure were probed with x-ray absorption spectroscopy and resonant x-ray emission spectroscopy (RXES). The intensity of the pre-edge peak at ~7112.7 eV of the Fe K-edge x-ray absorption spectrum of Fe(1.01)Se decreases for pressure from 0.5 GPa increased to 6.9 GPa. The satellite line Kβ' was reduced in intensity upon applying pressure and became absent for pressure 52 GPa. Fe(1.01)Se shows a small net magnetic moment of Fe(2+), likely arising from strong Fe-Fe spin fluctuations. The 1s3p-RXES spectra of Fe(1.01)Se at pressures 0.5, 6.9, and 52 GPa recorded at the Fe K-edge reveal that unoccupied Fe 3d states exhibit a delocalized character, stemming from hybridization of Fe 3d and 4p orbitals arising from a local distortion around the Fe atom in a tetrahedral site. Application of pressure causes suppression of this on-site Fe 3d-Fe 4p hybridization, and thereby decreases the intensity of the pre-edge feature in the Fe K-edge absorption spectrum of Fe(1.01)Se. Compression enhances spin fluctuations at Fe sites in Fe(1.01)Se and increases the corresponding T(c), through a competition between nearest-neighbor ferromagnetic and next-nearest-neighbor antiferromagnetic superexchange interactions. This result aids our understanding of the physics underlying iron-based superconductors.

We investigated both the dependence of electronic structures and spin states on pressure up to 25 GPa and the hybridization of Mn 3$d$ states in BiMnO${}_{3}$ by combining measurements of x-ray absorption, x-ray emission, and 1$s$3$p$-resonant x-ray emission spectroscopy (RXES). The Mn $K$-edge x-ray absorption spectra of BiMnO${}_{3}$ show a great change for pressure \ensuremath{\sim}1 GPa, corresponding to the occurrence of a structural transition. The gradually diminished shoulder of the white line and subsequently increased intensity of the white line of Mn $K$-edge spectra on increasing the external pressure from 2 to \ensuremath{\sim}15 GPa are attributed to a diminished Jahn-Teller distortion of MnO${}_{6}$ octahedra in BiMnO${}_{3}$ with increasing pressure. For pressure g\ensuremath{\sim}15 GPa, the intensity of the white line in Mn $K$-edge spectra of BiMnO${}_{3}$ became progressively decreased. Preedge peaks in Mn $K$-edge spectra of BiMnO${}_{3}$ at $P$ = 25 GPa shifted to smaller energy \ensuremath{\sim}0.3 eV relative to $P$ = 0.7 GPa. The spin magnetic moments deduced from the $K\ensuremath{\beta}$ emission line show a significant decrease for pressures between 0 and 2 GPa, then a monotonic decrease for pressures between 2 and 7 GPa, and a slight decrease after 7 GPa. The 1$s$3$p\ensuremath{-}$RXES spectra obtained at the Mn-$K$ preedge for BiMnO${}_{3}$ reveal that the empty Mn 3$d$(${e}_{g}^{0}$) states exhibit a delocalized character, suggested to originate from the hybridization of the unoccupied Mn 3$d$ states with the Mn 4$p$ orbitals. These findings provide insight into the evolution of electronic structures related to the structural transformation of multiferroic BiMnO${}_{3}$ under pressure.

We investigated the dissociation dynamics of positive-ion and negative-ion fragments of gaseous and condensed HCCl(3) following photoexcitation of Cl 2p electrons to various resonances. Based on ab initio calculations at levels HF/cc-pVTZ and QCISD/6-311G∗, the first doublet structures in Cl L-edge x-ray absorption spectrum of HCCl(3) are assigned to transitions from the Cl (2P(3/2),(1/2)) initial states to the 10a(1)(∗) orbitals. The Cl 2p → 10a(1)(∗) excitation of HCCl(3) induces a significant enhancement of the Cl(+) desorption yield in the condensed phase and a small increase in the HCCl(+) yield in the gaseous phase. Based on the resonant photoemission of condensed HCCl(3), excitations of Cl 2p electrons to valence orbitals decay predominantly via spectator Auger transitions. The kinetic energy distributions of Cl(+) ion via the Cl 2p → 10a(1)(∗) excitation are shifted to higher energy ∼0.2 eV and ∼0.1 eV relative to those via the Cl 2p → 10e(∗) excitation and Cl 2p → shape resonance excitation, respectively. The enhancement of the yields of ionic fragments at specific core-excited resonance states is assisted by a strongly repulsive surface that is directly related to the spectator electrons localized in the antibonding orbitals. The Cl(-) anion is significantly reinforced in the vicinity of Cl 2p ionization threshold of gaseous HCCl(3), mediated by photoelectron recapture through post-collision interaction.

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The dependence on pressure and temperature of the local structure and electronic state for MnO6 octahedra in orthorhombic DyMnO3 is investigated with Raman scattering, lifetime-broadening-suppressed x-ray absorption spectra and x-ray emission spectra. With increasing pressure, all Raman-active modes of DyMnO3 persist and shift monotonically to greater wavenumbers, implying that no structural change occurs under an external pressure up to \({\sim}32\) GPa. The spectral weight of the white line in Mn \(K\)-edge x-ray absorption spectra of DyMnO3 increased progressively, whereas the pre-edge feature gradually shifted to smaller energy upon increasing pressure. The Jahn–Teller distortion of MnO6 octahedra in DyMnO3 is progressively diminished with increasing pressure. The energy of the pre-edge line increased upon cooling from 300 to 10 K, in contrast with the pressure effect. A gradual breakdown of the high-spin state for MnO6 octahedra in DyMnO3 is observed. This work provides insight into structural modifi...