Attractive Power Research Articles

Effect of anode conditions on the performance of direct borohydride–hydrogen peroxide fuel cell system

Direct borohydride–hydrogen peroxide fuel cells (DBHPFCs) are attractive power sources for space applications. Although the cathode conditions are known to affect the system performance, the effect of the anode conditions is rarely investigated. Thus, in this study, a DBHPFC system was tested under various anode conditions, such as electrocatalyst, fuel concentration, and stabilizer concentration, to investigate their effects on the system performance. A virtual DBHPFC system was analyzed based on the experimental data obtained from fuel cell tests. The anode electrocatalyst had a considerable effect on the mass and electrochemical reaction rate of the fuel cell system, but had minimal effect on the decomposition reaction rate. The NaBH4 concentration greatly influenced the mass and decomposition reaction rate of the fuel cell system; however, it had minimal impact on the electrochemical reaction rate. The NaOH concentration affected the electrochemical reaction rate, decomposition reaction rate, and mass of the fuel cell system. Therefore, the significant effects of the anode conditions on the electrochemical reaction rate, decomposition reaction rate, and mass of the fuel cell system prompt the need for their careful selection through fuel cell tests and system analysis.

Three conceptual models of restorative environments based on user’s restorative experience in the COVID-19 pandemic period

ABSTRACT The COVID-19 pandemic is not just a medical phenomenon, for it impacts not only physical health but the world’s increasing psychological burden. One of the efforts that can be made to reduce this burden is visiting places than can be considered capable of supporting the restoration process. Therefore, this study aims to understand the restorative experience felt by a group of people in Indonesia towards a particular environment or place during the COVID-19 pandemic. Data was collected through an online-based cross-sectional survey from 11th September to 13 October 2020 with 261 participants. The data were then analyzed using the content analysis method, which consisted of three stages: open coding, axial coding, and selective coding. The results show that there are three types of restorative environments commonly visited during the COVID-19 pandemic: Dependent Restorative Environment (D-REn), Conventional Restorative Environment (C-REn), and Enclosed Restorative Environment (E-REn). Each type of environment has a unique characteristic that cannot be found in other types. D-REn depends on routine and interaction, while C-REn heavily relies on the power of attraction, especially the value of visual appeal. On the other hand, E-REn exists because of the lack of choice, making it unpredictable and out of the box.

Superparamagnetic characteristic of surface capped Mg0.5Zn0.5Fe2O4 nanoparticles reinforced polycarbonate nanocomposite fibers with mixed magnetic phases

The purpose of this work is to prepare magnetic polycarbonate nanocomposite fibers from nonmagnetic polycarbonate material by electrospinning method. This was achieved by the incorporation of oleic acid capped magnesium zinc ferrite (Mg0.5Zn0.5Fe2O4) nanoparticles during the spinning process. The presence of uniformly distributed surface capped Mg0.5Zn0.5Fe2O4 nanoparticles in the polymer nanofibers was detected by TEM investigation. The nanocomposite fibers retained and exhibited the excellent surface morphology as that of the plane polycarbonate fibers prepared under the same solution and spinning parameters. FT-IR and XRD studies revealed that, there did not happen any degradation to the polycarbonate material even with a high nanofiller load or under a high applied potential during electrospinning. UV-Visible spectral study shows that the polycarbonate nanocomposite fibers attained attractive visible light absorption power. The increased polymer entanglement by the proper interaction with the ferrite nanoparticles attributes to the increase in the glass transition temperature of the nanocomposite fibers. The VSM analysis was carried out to find the magnetic parameters like saturation magnetization, coercivity and retentivity of the composite fibers. Mossbauer spectral analysis was done to know the isomer shift, quadrupole splitting and the average hyperfine field. PC-Mg0.5Zn0.5Fe2O4 composite nanofibers exhibit quadrupole splitting values between 0.35 and 0.57 mm/s

A modified binary version of aphid–ant mutualism for feature selection: a COVID-19 case study

AbstractThe speedy development of intelligent technologies and gadgets has led to a drastic increment of dimensions within the datasets in recent years. Dimension reduction algorithms, such as feature selection methods, are crucial to resolving this obstacle. Currently, metaheuristic algorithms have been extensively used in feature selection tasks due to their acceptable computational cost and performance. In this article, a binary-modified version of aphid–ant mutualism (AAM) called binary aphid–ant mutualism (BAAM) is introduced to solve the feature selection problems. Like AAM, in BAAM, the intensification and diversification mechanisms are modeled via the intercommunication of aphids with other colonies’ members, including aphids and ants. However, unlike AAM, the number of colonies’ members can change in each iteration based on the attraction power of their leaders. Moreover, the second- and third-best individuals can take the place of the ringleader and lead the pioneer colony. Also, to maintain the population diversity, prevent premature convergence, and facilitate information sharing between individuals of colonies including aphids and ants, a random cross-over operator is utilized in BAAM. The proposed BAAM is compared with five other feature selection algorithms using several evaluation metrics. Twelve medical and nine non-medical benchmark datasets with different numbers of features, instances, and classes from the University of California, Irvine and Arizona State University repositories are considered for all the experiments. Moreover, a coronavirus disease (COVID-19) dataset is used to validate the effectiveness of the BAAM in real-world applications. Based on the acquired outcomes, the proposed BAAM outperformed other comparative methods in terms of classification accuracy using various classifiers, including K nearest neighbor, kernel-based extreme learning machine, and multi-class support vector machine, choosing the most informative features, the best and mean fitness values and convergence speed in most cases. As an instance, in the COVID-19 dataset, BAAM achieved 96.53% average accuracy and selected the most informative feature subset.

Transient Fault Signal Identification of AT Traction Network Based on Improved HHT and LSTM Neural Network Algorithm

This paper aims to address the difficult to pinpoint fault cause of the full parallel AT traction power supply system with special structure. The fault characteristics are easily covered up, and high transition impedance only affects the singularity of the wavehead, making the traveling waves hard to identify. Moreover, the classification accuracy of the traditional time-frequency analysis method is not sufficiently high to distinguish precisely. In this paper, a fault classification method of traction network based on single-channel improved Hilbert–Huang transform and deep learning is proposed. This method extracts effective fault features directly from the original fault signals and classifies the fault types at the same time. The accuracy of data categorization is increased by directly applying the Hilbert–Huang transform to fault signals to extract transient fault features and produce one-dimensional feature data, which are analyzed by the time-frequency energy spectrum. Using the similarity recognition method of long-short-term memory neural network, the extracted high-frequency one-dimensional feature data are trained and tested to classify fault signals more accurately. In order to verify the effectiveness of this method, several kinds of short-circuit and lightning strike faults are continuously simulated and verified in this paper. Considering various fault conditions and factors, the proposed improved HHT+LSTM method is compared with the LSTM method for direct processing of the original signals. The improved HHT + LSTM classification algorithm achieves an accuracy of 99.99%.

Understanding Turkish Soft Power in Africa: The Deepening of Kenya-Türkiye Relations 2000–2022

Türkiye has become an assertive player in soft power politics since Joseph Nye coined the term and its subsequent adoption by leaders as a coherent external relations strategy. Focusing on Africa from the beginning of 2000, Türkiye has built its structures of influence and steadily expanded its persuasion on the continent. The wielding of Türkiye’s soft power in Africa is yet to receive sufficient academic attention. This study attempts to contextualise the extent of Türkiye’s attractive power using the flourishing social economic relations with Kenya as a case study. Soft power is necessary in enhancing people-to-people relations, knowledge and information sharing, improvement of trade networks, and staging of coalitions against global threats.

Ultralight coaxial fiber-shaped zinc-ion hybrid supercapacitor with high specific capacitance and energy density for wearable electronics

Zinc-ion hybrid supercapacitors (ZHSs) with a fiber-shaped form are strongly desired for flexible electronics, but the construction still remains a great challenge. Herein, by using a graphene/multi-walled carbon nanotubes (MWCNTs) hybrid tube (GMHT) as cathode and a 2D nanostructured Zn modified graphene/MWCNTs tube (Zn@GMHT) as anode, we, for the first time, fabricate a ‘sword-scabbard’ like coaxial fiber-shaped all-solid-state ZHSs. The core-sheath structure notably accelerates electron transport and ion diffusion, and in comparison with the commonly used Zn metal electrode, an astounding 84.1 % anode mass reduction has been realized. Specifically, the optimized GMHT//Zn@GMHT ZHSs presents a superb length specific capacitance of 470.6 mF cm−1 (relevant to an outstanding areal/volumetric capacitance of 735.3 mF cm−2/19.6 F cm−3) at the current density of 1 mA cm−1, which is obviously better than most of the reported fiber-shaped ZHSs. Meanwhile, the device shows a maximum energy density of 167.3 μWh cm−1 at the power density of 533.5 μW cm−1, and an attractive power density of 5988.1 μW cm−1 at 16.8 μWh cm−1. Moreover, the capacitance retentions of 84.6 % after 5000 charge–discharge cycles and 100–88.3 % under bending angles from 0 to 150° demonstrate great electrochemical stability and mechanical flexibility of the device. The admirable properties, together with this creative architecture and ultralight function, endow GMHT//Zn@GMHT with a broad prospect in wearable application.

МИССИОНЕРСКАЯ И ПРОСВЕТИТЕЛЬСКАЯ ДЕЯТЕЛЬНОСТЬ РУССКОЙ ПРАВОСЛАВНОЙ ЦЕРКВИ НА УРАЛЬСКОМ СЕВЕРЕ В КОНЦЕ XIX — НАЧАЛЕ XX В.

The article analyzes the activities of the literacy schools created by the Ekaterinburg Diocesan Committee of the Orthodox Missionary Society in the Verkhotursky uyezd of the Perm province: their financial and material support, methods of educational work, the level of educational training and material support of teachers. For the spread of Orthodoxy among the settled Mansi, the committee created four schools: in 1887 — in the village of Lacha, in 1888 — in Lopaeva, in 1890 — in Mityaeva, in 1891 — Petrova. “Vogul Schools” worked according to the program of parish schools, which included the study of the following subjects: the Law of God, Church Slavonic literacy, the Russian language and reading of civilian press, arithmetic, calligraphy, church singing. The training lasted three years and was conducted in Russian. The main task of church schools was “awakening in children of sincere love for the Church of God and the development of religious feelings in their souls”. The missionaries were confident in the beneficial and attractive power of Christian ideas, capable of turning the gentiles and “infidels” to Orthodoxy. The government, supporting missionary schools, saw in them a means of spreading the Russian language and integration of the empire’s non-Russian peoples into a single economic and cultural space. In 1907, missionary schools were transferred to the jurisdiction of the Ekaterinburg diocesan school council. At that time, there were 20 students (10 boys and 10 girls) in the Lachinsky school, in Mityaevskaya — 10 (6 boys and 4 girls), in Lopaevskaya — 28 (19 boys and 9 girls), in Petrovskaya — 23 (16 boys and 7 girls). During the school reform of the early 20th century all these schools were closed. Only the Petrovsky school was preserved, which was completed by students and transformed into a parish school. Attempts by the Ekaterinburg branch of the Orthodox Missionary Society to organize schools to teach children of the nomad Mansi failed.

Boosting the Electrode Reaction Kinetics of SSOFCs by the Synergistic Effect of Nanoparticle Codecoration on Both the Cathode and Anode

A novel (SmBa)0.9Mn1.8Co0.2O5+δ (SBMCo) electrode is elaborately designed for symmetrical solid oxide fuel cells (SSOFCs). In operating conditions, the SBMCo material is codecorated with exsolved metallic cobalt for the anode and cobalt oxide for the cathode. The electrochemical impedance spectroscopy (EIS) results combined with distribution of relaxation times (DRT) analysis reveal that the rate-limiting step for hydrogen oxidation at the anode is the adsorbed hydrogen dissociation process, while for the oxygen reduction at the cathode, it is the charge transfer process. The exsolved nanoparticles on the SBMCo backbone of Co and Co3O4 significantly promote the corresponding rate-limiting steps and enable the decorated electrodes to exhibit remarkable catalytic activity toward hydrogen oxidation and oxygen reduction, respectively. When fueled with humidified hydrogen, the constructed symmetrical cell based on the designed SBMCo electrodes with the 300 μm La0.8Sr0.2Ga0.8Mg0.2O3−δ (LSGM) electrolyte-supported configuration delivers an attractive maximum power density of 712 mW cm–2 at 900 °C. The results demonstrate that the elaborate design of the codecorated anode and cathode from a single parent compound is a promising route for the development of candidate electrodes for SSOFCs.

Attractant Activity of Host-Related Chemical Blends on the Poultry Red Mite at Different Spatial Scales

Many blood-feeding arthropods use volatile organic compounds (VOCs) to detect their vertebrate hosts. The role of chemical interactions in mediating the behavior of hematophagous insects and ticks has been investigated before but remains poorly understood in hematophagous mesostigmatic mites. The poultry red mite Dermanyssus gallinae is an obligatory blood-sucking mesostigmatic mite that feeds on birds and causes damage in poultry farms. We characterized the attractive response of D. gallinae to candidate VOCs previously reported from the odor emitted by living hens. We performed in-vitro choice-test bioassays as well as semi-field and field trials using baited and unbaited traps, in the presence and absence of hens. Among different tested combinations of VOCs, a blend of 5 VOCs (mix1.0) was significantly attractive to our reference population of D. gallinae in vitro, whereas the same individual compounds tested alone were not attractive. Ammonia was attractive on its own and increased the mix1.0 attractiveness. The attractiveness of mix1.0 was confirmed at 'natural' spatial scales in the absence of hens both at the lab and on the farm that provided the reference population. The presence of hens inhibited the mix1.0 attractiveness. The attractive power of mix1.0 was not found in other farms. This research is an important step to advance our understanding of host-parasite interactions in hematophagous mesostigmatic mites and paves the way for developing alternative control tools against D. gallinae by interfering with chemical interactions. Moreover, it underlines the importance of assessing kairomonal activity on different pest populations when developing attract-and-kill systems.

Hazel shell-based biomass-derived carbon modified diaphragm for high-performance lithium-sulfur batteries

Lithium-sulfur battery has become one of the most attractive power battery systems in the future because of their high specific energy, high energy density, good safety, green environmental protection, low cost, and so on. However, due to the "shuttle effect" caused by its polysulfide discharge product, the lithium-sulfur battery's cycle performance is poor, limiting the rapid development of lithium-sulfur batteries. In this paper, oxygen-doped hazel shell-graded porous derivative carbon with a high specific surface area was prepared by a simple template-free method and used as the functional layer of the diaphragm. Oxygen self-doping is beneficial to forming oxygen-containing functional groups on the surface, which can realize the chemical adsorption of polysulfides. The multi-stage pore structure enhances the physical confinement effect of carbon materials on polysulfides. In addition, it is found that the initial capacity of the modified diaphragm can reach 1318.8 mAh g-1 at 0.2C current density. And the initial capacity can still reach 1035.6 mAh g-1 even at 1 C current density, after 500 cycles, the capacity retention rate is 60.9%, which has good rate performance and cycle stability.

Negative Theology and Theophany in Dante’s Paradiso

Dante’s Paradiso presents a gothic theophany realizing the divine vision (visio Dei) in poetic language. Specifically, Dante’s vision of a line from Scripture (DILIGITE IUSTITIAM QUI IUDICATIS TERRAM) in the Heaven of Jove (Canto XVIII) gives a concrete form of written letters to his vision of God. Yet all that Dante actually sees is only a sign of the invisible, metaphysical reality of God and the supersensible universe of pure being or love. This tension between the sensory plenitude of his vision and the transcendent truth that Dante envisages lends his poem its extraordinary force and attractive power. The paradoxes of negative theology and its inevitable relation with an affirmative theology expressed as poetic vision are worked out with matchless subtlety in Dante’s descriptions and reflections, some of which are expounded in a speculative key in this essay drawn from a more detailed and comprehensive inquiry into the subject. The immediacy of Dante’s vision of letters of Scripture in the Heaven of Jove serves as a metaphor for an unmediated vision of God, but the vision’s content turns out to be nothing other than mediation – concretely, language as the medium mediating his relation to God as Logos. Dante’s vision from beginning to end of the Paradiso is placed under the sign of the ineffability topos, yet what he sees are words and language and ultimately letters. Dramatically displaying the mediations in which language consists becomes itself a metaphorical realization of divine revelation. The mechanisms of signifying in languagemade visibly manifest in writing and specifically as the first line of the Book of Wisdom in Scripture are unveiled as a negatively theological revelation of divinity.

Soft power kultury rosyjskiej w kontekście wojny Federacji Rosyjskiej przeciwko Ukrainie

The article aims to look at Russian culture as a soft power through the prism of the large-scale invasion of the Russian Federation against Ukraine and to analyze the changes in its perception that have occurred as a result of these events. Russian culture, especially high culture, is known and appreciated in the world, which gives it the power of attraction and the possibility of exerting influence. At the same time, it is not only a source of prestige and a tool for promoting Russia, but also spreading Russian imperial myths that contributed to the invasion of Ukraine. Moreover, the operation of Russian cultural institutions outside the borders of the Russian Federation is strictly controlled by the authorities, and its popularization is treated as a “special operation”. Russian culture imposed imperial optics on the perception of “near abroad”, deprived Ukraine of the right to its history, identity and cultural heritage. Due to its colonial nature, it does not perceive the suffering of oppressed nations, and is therefore unable to prevent the tragedy of their destruction, as is the case with Ukraine and its culture. As a result of the initiated war, Russia has embezzled some of its soft power. However, there is no consensus among the international community regarding the imposition of sanctions on Russian culture. Ukrainian cultural activists accuse the international community of hypocrisy because, in defending Russian culture, it does not perceive the deliberate and systematic destruction of Ukrainian culture. Russian culture requires a reinterpretation and unmasking of the imperial optics, as consuming it indiscriminately poses a threat to the national security of the “near abroad” states.

Sensitivity Analysis of Capital Cost of European DEMO Design

Conceptual designs for a European demonstration (EU-DEMO) power plant are based on extrapolations of physics scaling laws and current understanding of engineering limits based on available technologies. It is imperative to quantify the impact of uncertainties in physics and engineering parameters on the ability to produce an economically attractive future fusion power plant that meets key design outcomes. In this work, the sensitivity of the expected capital cost of an EU-DEMO power plant has been studied using the systems code PROCESS. A systems code aims to model interactions between subsystems of a fusion power plant and provide consistent solution across a large parameter space. The PROCESS system code allows for user-defined initial conditions and constraints and then optimizes using a given figure of merit to find optimal design parameters. We present a sensitivity analysis on optimizations around the 2018 pulsed EU-DEMO baseline, and this allows for the identification of the most consequential model parameters and the magnitude of the nonlinear interactions between them. We consider the pulsed EU-DEMO baseline, and while fixing the major radius and optimizing for fusion gain <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> , we present a sensitivity analysis of the role of the physics and engineering parameters and constraints in determining the capital cost of such a device. We identify the dominant physics parameter as the power threshold necessary to enter H-mode, which accounts for 45% of the sensitivity and find high interactions between plasma shaping parameters and other power plant subsystems. This analysis allows for the identification of areas of additional technical focus and uncertainty propagation.

Potassium Methacrylate Additive Strategy for Improved Stability of Ultrathin Copper‐Based Perovskite Solar Cells

AbstractPerovskite solar cell (PSC) using ultrathin metal transparent electrode is a promising power source for wearable electronics and aerospace applications. However, the environmental stability of device is challenging, due to the undesirable interdiffusion of metal and halogen ions. In this work, PSCs are constructed by using ultrathin copper (Cu) electrodes with low reactivity, combined with potassium methacrylate (KMMA) additive. On one hand, carbonyl groups in KMMA interact with the perovskite and improve quality of perovskite films. As a result, the power conversion efficiency (PCE) of ultrathin Cu‐based PSC is increased from 12.49% to 14.72%. On the other hand, benefitting from the binding of K+ with halogen ion, the interdiffusion of Cu and I ions is hindered. Thus, PSCs retain 80% and 75% of the initial PCE under heating at 85 °C for 130 h and maximum power point for 300 h, respectively. To the best of the knowledge, it is one of the best thermal and operational stability for the PSCs using metal‐based electrodes. At last, the symmetric PSCs exhibit superior folding stability which maintain 85.3% of initial PCE after folding for 500 cycles. Foldable PSCs on ultrathin Cu electrodes with excellent stability are attractive power sources in wearable applications.

An asymmetric MnO2|activated carbon supercapacitor with highly soluble choline nitrate-based aqueous electrolyte for sub-zero temperatures

• Eutectic of choline nitrate and water maintains liquid state down to -100°C. • MnO 2 /carbon supercapacitor at 1.8 V operates down to -40°C. • Charge compensation in MnO 2 by the nitrate ions in presence of bulky choline cations. MnO 2 |activated carbon supercapacitors are attractive power devices that rival the electric double-layer capacitors (EDLCs) due to high reachable voltage. However, they greatly suffer from performance loss at low temperature as most of aqueous electrolytes freeze below ca. -10°C. Here, a concentrated choline nitrate-based (5 mol/L aqueous ChNO 3 ) electrolyte is applied to extend the working temperature range due to its eutectic-like properties. In such electrolyte, water acts as hydrogen bond donor for nitrate anion and low hydration energy for large choline cations favors ionic transport. The MnO 2 /CNT composite electrode with a hierarchical structure has been synthesized by hydrothermal process. The presence of CNTs as core component facilitates the electron conduction, while the two-dimensional MnO 2 flakes grown on the surface provide electrolyte transport pathways and improve the interfacial processes (pseudocapacitive charge/discharge). Thanks to the low hydration of choline cation, the individual activated carbon (AC, negative) and MnO 2 /CNT (positive) electrodes are charged symmetrically up to a cell voltage of 1.8 V. Overall, due to the wide electrochemical stability window (∼2.0 V) and anti-freezing properties of ChNO 3 -based aqueous electrolyte and the hierarchical design of the MnO 2 /CNT composite, the asymmetric supercapacitor operates down to -40 °C and displays excellent energy and coulombic efficiency with no loss of performance after several thousand cycles. This work provides a new possibility on the low temperature application of high voltage supercapacitors.

Multifunctional NiTiO3-decorated-rGO nanostructure for energy storage, electro- and photocatalytic applications

Herein, we report a synthesis of nanostructured multifunctional material: flakes of reduced graphene oxide decorated with NiTiO3 particles (NiTiO3/rGO). The structural and morphological features of the NiTiO3/rGO composite were investigated via X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), nitrogen adsorption/desorption analysis, Raman, infrared and UV–Vis spectroscopy techniques. The electrochemical performance was scrutinized through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge measurements (GCD). The NiTiO3/rGO composite demonstrates an outstanding specific capacitance of 551 F g−1 (at 10 mV s−1) and an excellent capacitance retention (121 %). Its specific surface area (53 m2 g−1) increased by 100 % with respect to the pristine NiTiO3. The junction of NiTiO3 with rGO endowed the titanate with the mesoporous structure. NiTiO3/rGO presents supercapacitor behavior and has an attractive power characteristic with power density of 9718 W kg−1 (at 20 A g−1). The charge transfer resistance for NiTiO3/rGO, 56 Ω, is 2-fold smaller than for the bare NiTiO3. The composite behaved as electrocatalyst; it enhanced sensitivity of dopamine electrochemical detection. Biosensor showed linearity in the range 1–60 μM and limit of detection of 2.84 μM. NiTiO3/rGO also acted as visible-light harvesting photocatalyst and facilitated degradation of pharmaceutical pollutant, i.e. nizatidine. Photodegradation efficiency reached 35 % and 85 % with NiTiO3 and NiTiO3/rGO, respectively.

Understanding the phase and solvation behavior of fluorinated ionic liquids

• Effect of perfluoroalkyl chains on the properties and phase equilibria of FILs. • VLE of FILs show the need of optimal fluorine density to enhance gas absorption. • LLE of FILs reveal high surfactant behavior in water and improved PFCs solubility. • SLE of FILs uncover formation of eutectic mixtures with complex phase behavior. • FILs show huge relevance in GHGs capturing processes and biomedical applications. Fluorinated ionic liquids (FILs) are defined as molecules having fluorinated tags equal to or longer than 4 carbon atoms in the anion and/or cation structures. They present nanosegregated domains making them 3-in-1 solvents with exceptional properties, including an attractive solubility power. This work is an important contribution towards understanding the current research on the phase behavior of FILs, which may be used as task-specific materials for industrial applications. An overview of the main works published in the last two decades is presented, concerning gas solubility in FILs, the application of membranes to improve the gas absorption in FILs, and the use of modeling approaches to ease the application of FILs in gas capture and separation processes, with emphasis on the relationship between the structural properties and their performance. Contributions concerning the liquid-liquid and solid-liquid equilibria behavior of FILs, including the liquid-liquid equilibria (LLE) of FILs in water and perfluoroalkanes, and the solid-liquid equilibria (SLE) of solid FILs in water and mixtures of FILs are also presented. Regarding the absorption of gases in FILs, a careful analysis of the published works reveals that: (1) an optimal density of fluorine atoms in FILs structure is required to positively impact the absorption of different gases, (2) the functionalization of membranes can be also a useful method to improve the performance in separation processes, and (3) modeling tools can ease the screening of the features that promote the absorption of gases by FILs. The study of FILs LLE showed a rich phase behavior with water and perfluoroalkanes and the enhanced surfactant power of FILs, which is highly dependent on the length of the hydrogenated and fluorinated side chains. Finally, studying the SLE of FILs mixtures allowed the formation of deep eutectic systems that enlarges the applicability of FILs.

High frequency response of adenine-derived carbon in aqueous electrochemical capacitor

Electrochemical capacitors are attractive power sources, especially when they are able to operate at high frequency (high current regime). In order to meet this requirement their constituents should be made of high conductivity materials with a suitable porosity. In this study, enhanced power and simultaneously high capacitance (120 F g−1 at 1 Hz or 10 A g−1) electrode material obtained from carbonized adenine precursor is presented. A micro/mesoporous character of the carbon with optimal pore size ratio and high surface area was proven by the physicochemical characterization. The beneficial pore structure and morphology resembling highly conductive carbon black, together with a significant nitrogen content (5.5%) allow for high frequency response of aqueous capacitor to be obtained. The carbon/carbon symmetric capacitor (in 1 mol L−1 Li2SO4) has been tested to the voltage of 1.5 V. The cyclic voltammetry indicates a good electrochemical response even at high scan rate (50 mV s−1). The cyclability of the capacitor is comparable to the one operating with commercial carbon (YP50F). The adenine-based capacitor is especially favourable for stationary applications requiring high power.

Graphene-nanopocket-encaged PtCo nanocatalysts for highly durable fuel cell operation under demanding ultralow-Pt-loading conditions.

The proton exchange membrane fuel cell (PEMFC) as an attractive clean power source can promise a carbon-neutral future, but the widespread adoption of PEMFCs requires a substantial reduction in the usage of the costly platinum group metal (PGM) catalysts. Ultrafine nanocatalysts are essential to provide sufficient catalytic sites at a reduced PGM loading, but are fundamentally less stable and prone to substantial size growth in long-term operations. Here we report the design of a graphene-nanopocket-encaged platinum cobalt (PtCo@Gnp) nanocatalyst with good electrochemical accessibility and exceptional durability under a demanding ultralow PGM loading (0.070 mgPGM cm-2) due to the non-contacting enclosure of graphene nanopockets. The PtCo@Gnp delivers a state-of-the-art mass activity of 1.21 A mgPGM-1, a rated power of 13.2 W mgPGM-1 and a mass activity retention of 73% after an accelerated durability test. With the greatly improved rated power and durability, we project a 6.8 gPGM loading for a 90 kW PEMFC vehicle, which approaches that used in a typical catalytic converter.