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[Display omitted] • Free-standing composite papers of SFCP@PANI were prepared. • The free-standing SFCP@PANI-2 paper was directly utilized as supercapacitive electrodes. • The SFCP@PANI-2 demonstrated an enhanced electrochemcial capacitive performance. Free-standing composite papers of SFCP@PANI were prepared by in situ polymerization of aniline on the surface of sisal fiber carbon paper (SFCP). The SFCP@PANI papers can be directly built into electrodes without the need for any binders or conductive agents. SFCP@PANI-2 exhibits excellent electrochemical performance in the three-electrode system and the coin-type symmetric supercapacitor (SSC), which indicates that it may be a promising electrode material for supercapacitor. [ABSTRACT FROM AUTHOR]

We used the surface-pretreated graphite paper (Gp) as a carrier and loaded BiOCl with high selectivity to Cl− on its surface by solvothermal method to form BiOCl@Gp electrode. The morphology, structure, and composition of the materials were characterized by scanning electron microscopy and nitrogen adsorption/desorption, and the results showed that the spherical BiOCl particles were uniformly dispersed on the surface of the Gp, forming a mesoporous BiOCl@Gp composite with a specific surface area of 22.82 m2/g and a pore volume of 0.043 cm3/g. Furthermore, cyclic voltammetry and electrochemical impedance spectroscopy were used to test the electrochemical properties of the composites, and the stability of BiOCl and the high conductivity of Gp were synergistic, the BiOCl@Gp exhibited a specific capacitance of 30.2 F·g−1 at a current density of 0.5 A·g−1, and the selectivity of the BiOCl@Gp materials for Cl− was significantly higher than that of SO42−, NO2−, and HCO3−. Therefore, BiOCl@Gp composite electrode materials can be used for the selective adsorption of Cl− in wastewater, in order to achieve efficient wastewater recycling. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To develop emerging electrode materials and improve the performances of batteries, the machine learning techniques can provide insights to discover, design and develop battery new materials in high-throughput way. In this paper, two deep learning models are developed and trained with two feature groups extracted from the Materials Project datasets to predict the battery electrochemical performances including average voltage, specific capacity and specific energy. The deep learning models are trained with the multilayer perceptron as the core. The Bayesian optimization and Monte Carlo methods are applied to improve the prediction accuracy of models. Based on 10 types of ion batteries, the correlation coefficients are maintained above 0.9 compared to DFT calculation results and the mean absolute error of the prediction results for voltages of two models can reach 0.41 Vand 0.20 V, respectively. The electrochemical performance prediction times for the two trained models on thousands of batteries are only 72.9 ms and 75.7 ms. Besides, the two deep learning models are applied to approach the screening of emerging electrode materials for sodium-ion and potassium-ion batteries. This work can contribute to a high-throughput computational method to accelerate the rational and fast materials discovery and design. [ABSTRACT FROM AUTHOR]

The noble metal-based electrochemical sensor design for efficient and stable formaldehyde(FA) detection is important ongoing research. In this paper, PtPd/Nafion/GCE is prepared by electrochemical cyclic voltammetry deposition method based on electrodepositing nanostructured platinum (Pt)-palladium (Pd) nanoparticles in Nafion film-coated glassy carbon electrode (GCE). The influence of deposition parameters and chemical composition (atomic ratio of Pt and Pd) on the electrochemical behaviour of PtPd/Nafion/GCE has been investigated. PtPd/Nafion/GCE displays a remarked electrocatalytic activity for the oxidation of FA and exhibits a linear relationship in the range of 10–5000 μ M, with a detection limit of 3.3 μ M in 0.1 M H2SO4 solution. It is proved that the detection performance of PtPd/Nafion/GCE electrode is valuable for further application with low detection limit, wide linear range, favourable selectivity and high response. [ABSTRACT FROM AUTHOR]

An electrochemical CO2 reduction reaction (CO2RR) is an effective way to reduce greenhouse gases by converting CO2 into high-value-added chemical products using electricity generated from renewable energy. In this paper, a Cu2O spherical catalyst was prepared by ascorbic acid reduction. The precipitated Cu-Ag spherical catalyst (P-CuO-Ag) was successfully prepared by calcining Cu2O-Ag with the introduction of an Ag component as the substrate. During the electrochemical reduction of CO2, the FE of the P-CuO-Ag catalyst for C2H4 at a potential of −1.1 V vs. RHE was as high as 39.8%, which was nearly twice that of the CuO catalyst, while the local current density JC2H4 for C2H4 reached 6 mA cm−2. The incorporation of Ag gives the spherical CuO catalyst higher electrochemical activity and better kinetic performance than the catalyst without Ag. [ABSTRACT FROM AUTHOR]

Surface enhanced Raman spectroscopy (SERS) is a powerful analytical technique that has found application in the trace detection of a wide range of contaminants. In this paper, we report on the fabrication of 2D silver nanodendrites, on silicon chips, synthesized by electrochemical reduction of AgNO3 at microelectrodes. The formation of nanodendrites is tentatively explained in terms of electromigration and diffusion of silver ions. Electrochemical characterization suggests that the nanodendrites do not stay electrically connected to the microelectrode. The substrates show SERS activity with an enhancement factor on the order of 106. Density functional theory simulations were carried out to investigate the suitability of the fabricated substrate for pesticide monitoring. These substrates can be functionalized with cyclodextrin macro molecules to help with the detection of molecules with low affinity with silver surfaces. A proof of concept is demonstrated with the detection of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA). [ABSTRACT FROM AUTHOR]

Two diphosphanes with variable-length ligands tested as nucleophiles to prepare isoporphyrin copolymers in the presence of ditolylporphyrin of zinc (ZnT2P) prevented the oxidation of the diphosphine ligand. This paper demonstrates the power of this approach and describes the photoelectrocatalytic properties. The obtained copolymers were characterized by UV–vis spectroscopy, X-ray photoelectron spectroscopy, atomic force micrograph (AFM), EQCM (Electrochemical Quartz Cristal Microbalance) and electrochemistry. Their impedance properties (EIS) were studied and their photovoltaic performances were also investigated by photocurrent transient measurements under visible light irradiation. [ABSTRACT FROM AUTHOR]

The diketopyrrolopyrrole (DPP) unit represents one of the building blocks more widely employed in the field of organic electronics; in most of the reported DPP-based small molecules, this unit represents the electron acceptor core symmetrically coupled to donor moieties, and the solubility is guaranteed by functionalizing lactamic nitrogens with long and branched alkyl tails. In this paper, we explored the possibility of modulating the solubility by realizing asymmetric DPP derivatives, where the molecular structure is extended in just one direction. Four novel derivatives have been prepared, characterized by a common dithyenil-DPP fragment and functionalized on one side by a thiophene unit linked to different auxiliary electron acceptor groups. As compared to previously reported symmetric analogs, the novel dyes showed an increased solubility in chloroform and proved to be soluble in THF as well. The novel dyes underwent a thorough optical and electrochemical characterization. Electronic properties were studied at the DFT levels. All the dyes were used as active layers in organic field effect transistors, showing balanced charge transport properties. [ABSTRACT FROM AUTHOR]

This paper addresses the interplay between electrical fields in the human body and the corrosion behavior of Ti-6Al-4V alloy, a prevalent orthopedic material. The study investigates the impact of alternative electrical signals at different frequencies on the alloy's electrochemical behavior in a simulated body environment. The human body always has natural sinusoidal potential due to, e.g., heart palpitations and brain/nervous system activities. Ignoring such natural activities may lead to underestimating the corrosion performance of the Ti-6Al-4V alloy in the body. By analyzing anodic and cathodic responses and the net faradaic current induced by alternating current potential, the research sheds light on the influence of electrical fields on corrosion rates. Understanding these dynamics could lead to improved implant materials, mitigating corrosion-related challenges and enhancing implant performance over the long term. Results of this work indicated that frequent oxidation and reduction at certain frequencies may induce corrosion and hinder biomimetic apatite formation, impacting osseointegration. Natural alternative currents in the body affect the corrosion performance of Ti-based implant alloys, highlighting the need for consideration in biomedical applications. [ABSTRACT FROM AUTHOR]

With escalating global regulatory pressure for countries to adhere to emission laws, repurposing existing natural gas pipelines for hydrogen-based commodities stands to be an economical solution. However, the effects of hydrogen embrittlement must be thoroughly considered for this application to avoid the unexpected catastrophic failure of these pipelines. The literature proposes several physicochemical embrittlement models. This paper reports one aspect of hydrogen embrittlement that remains to be quantified: the recovery of ductility (embrittlement) of mild steel specimens subjected to artificially accelerated hydrogen absorption via electrochemical charging as a function of time. The effects of charging duration and particularly the delay period between charging and mechanical tensile testing were investigated. Unsurprisingly, longer charging time shows a greater loss of elongation; however, a more extensive recovery of ductility correlated with longer charging time in the first few days after charging. The data also show that while the uncharged mild steel met all minimum required values for strength and elongation for the specified grade, there was a substantial variability in the elongation to failure. The same trends in variability of elongation translated to the hydrogen-charged specimens. Due to this extensive variability, failure to meet the elongation specification of the grade is reported based on the worst-case scenario obtained for a given set of samples for each exposure condition. These results have practical implications for the monitoring and testing of infrastructure exposed to hydrogen, particularly as this relates to industry planned operational shutdown schedules. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) are favored in the fields of adsorption, separation, catalysis, electrochemistry, and magnetism due to their advantages of large specific surface area, high porosity, controllable pore size adjustment, and dispersion of metal active sites. The application of MOFs involves multiple fields, which requires that MOFs have good water stability, as gaseous and liquid water inevitably exist in industrial processes. In this paper, the research status of the stability of MOFs in aqueous solutions was reviewed in recent years, including the design and synthesis, the influencing factors, and the applications of MOFs in water stability. [ABSTRACT FROM AUTHOR]

In the CCUS project, CO2 utilization had achieved remarkable results in oil displacement. But, at present, one of the main reasons that seriously affected the large-scale application of CCUS projects was that the corrosion behavior of underground environment on pipe string or wellbore was not fully evaluated. It was revealed that the wellbore corrosion behavior in the harsh environment in the process of CO2 flooding was the key to ensure the safe production of oil fields. Therefore, this paper took the corrosion environment with temperature of 81.7°C, pressure of 52.3 MPa and high salinity in the well depth of 4517 m as the research object, to study the corrosion behavior of oil casing N80 steel through corrosion rate, corrosion morphology and electrochemical experiments. The results showed that the corrosion rate increased with the increase of experimental time, behaved by the charge transfer resistance decreased. However, when the experiment increased from 800 h to 1000 h, the pitting corrosion rate increased from 1.47 mm/a to 1.782 mm/a, which was consistent with the ratio of anode/cathode Tafel constants and corrosion density. This was mainly because the relatively dense FeCO3 corrosion product layer generated on the N80 steel surface gradually brook down due to synergistic effect of amorphous CrO3, Fe2+/Ca2+ complex salt and Cl– during the experiment, which promoted the initiation and development of the corrosion pits. Compared with the bare N80 steel, the incomplete corrosion product layer aggravated the rapid development of pitting corrosion. [ABSTRACT FROM AUTHOR]

In this paper, a novel aptamer-modified nitrogen-doped graphene microelectrode (Apt-Au-N-RGOF) was fabricated and used to specifically identify and detect dopamine (DA). During the synthetic process, gold nanoparticles were loaded onto the active sites of nitrogen-doped graphene fibers. Then, aptamers were modified on the microelectrode depending on Au-S bonds to prepare Apt-Au-N-RGOF. The prepared microelectrode can specifically identify DA, avoiding interference with other molecules and improving its selectivity. Compared with the N-RGOF microelectrode, the Apt-Au-N-RGOF microelectrode exhibited higher sensitivity, a lower detection limit (0.5 μM), and a wider linear range (1~100 μM) and could be applied in electrochemical analysis fields. [ABSTRACT FROM AUTHOR]

In this work, we conducted a study of the interaction between DNA and favipiravir (FAV). This chemotherapeutic compound is an antiviral drug for the treatment of COVID-19 and other infections caused by RNA viruses. This paper examines the electroanalytical characteristics of FAV. The determined concentrations correspond to therapeutically significant ones in the range of 50–500 µM (R2 = 0.943). We have shown that FAV can be electro-oxidized around the potential of +0.96 V ÷ +0.98 V (vs. Ag/AgCl). A mechanism for electrochemical oxidation of FAV was proposed. The effect of the drug on DNA was recorded as changes in the intensity of electrochemical oxidation of heterocyclic nucleobases (guanine, adenine and thymine) using screen-printed graphite electrodes modified with single-walled carbon nanotubes and titanium oxide nanoparticles. In this work, the binding constants (Kb) of FAV/dsDNA complexes for guanine, adenine and thymine were calculated. The values of the DNA-mediated electrochemical decline coefficient were calculated as the ratio of the intensity of signals for the electrochemical oxidation of guanine, adenine and thymine in the presence of FAV to the intensity of signals for the electro-oxidation of these bases without drug (S, %). Based on the analysis of electrochemical parameters, values of binding constants and spectral data, intercalation was proposed as the principal mechanism of the antiviral drug FAV interaction with DNA. The interaction with calf thymus DNA also confirmed the intercalation mechanism. However, an additional mode of interaction, such as a damage effect together with electrostatic interactions, was revealed in a prolonged exposure of DNA to FAV. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of water content on lithium-ion battery electrolytes with particular emphasis on the degradation of lithium hexafluorophosphate, a commonly used salt in commercial electrolytes. The study addresses various degradation mechanisms caused by water in a battery system. In addition, the research utilizes electrochemical techniques to detect water and associated changes in electrochemical performance of the cell. The electrochemical water detection method investigated is very fast. The lower detection limit was not tested, but contamination of 250 ppm can be reliably detected. It can be used, for example, in experimental research to determine the purity and quality of the electrolyte used. [ABSTRACT FROM AUTHOR]

GeFe2O4 (GFO) is a germanium mineral whose spinel crystal structure determines its interesting functional properties. Recently, it was proposed for application as an anode for Sodium and Lithium-Ion Batteries (SIBs and LIBs) thanks to its combined conversion and alloying electrochemical mechanism. However, its entire potential is limited by the poor electronic conductivity and volumetric expansion during cycling. In the present paper, pure and Sn or Mg doped GFO samples obtained from mechano-chemical solid-state synthesis and properly carbon coated were structurally and electrochemically characterized and proposed, for the first time, as anodes for SIBs. The spinel cubic structure of pure GFO is maintained in doped samples. The expected redox processes, involving Fe and Ge ions, are evidenced in the electrochemical tests. The Sn doping demonstrated a beneficial effect on the long-term cycling (providing 150 mAh/g at 0.2 C after 120 cycles) and on the capacity values (346 mAh/g at 0.2 C with respect to 300 mAh/g of the pure one), while the Mg substitution was less effective. [ABSTRACT FROM AUTHOR]

Highlights: Critical solvation structure changes the hydrogen bond network through "catchers". Catcher further arrests the active molecules to promote Zn2+ deposition. The Zn||Zn symmetric battery can stably cycle for 2250 h. Zn||V6O13 full battery achieved a capacity retention rate of 99.2% after 10,000 cycles. Aqueous Zn-ion batteries (AZIBs) have attracted increasing attention in next-generation energy storage systems due to their high safety and economic. Unfortunately, the side reactions, dendrites and hydrogen evolution effects at the zinc anode interface in aqueous electrolytes seriously hinder the application of aqueous zinc-ion batteries. Here, we report a critical solvation strategy to achieve reversible zinc electrochemistry by introducing a small polar molecule acetonitrile to form a "catcher" to arrest active molecules (bound water molecules). The stable solvation structure of [Zn(H2O)6]2+ is capable of maintaining and completely inhibiting free water molecules. When [Zn(H2O)6]2+ is partially desolvated in the Helmholtz outer layer, the separated active molecules will be arrested by the "catcher" formed by the strong hydrogen bond N–H bond, ensuring the stable desolvation of Zn2+. The Zn||Zn symmetric battery can stably cycle for 2250 h at 1 mAh cm−2, Zn||V6O13 full battery achieved a capacity retention rate of 99.2% after 10,000 cycles at 10 A g−1. This paper proposes a novel critical solvation strategy that paves the route for the construction of high-performance AZIBs. [ABSTRACT FROM AUTHOR]

The presence of an alternative framework in the students' minds acts as the main hindrance to students exhibiting profound understanding of scientific concepts, which in turn promotes the application of scientific knowledge to solve daily life context problems. This research is done in two phases. In the first phase, the research aims to identify the alternative framework among students on the concept of electrochemistry, and in the second phase, it develops an instructional module for secondary school students on the concept of electrochemistry by using the five-phase Needham constructivism model approach to overcome the alternative framework that exists in the students' minds. In this paper, however, only the findings of the first phase are reported. The instrument used for this study is the electrochemistry test developed based on previous research and validated by experts. This paper and pencil test is used in the first phase of the research as a data collection tool. This research adapted a quantitative research design. The data from the electrochemistry test is analyzed using statistical packages for social sciences (SPSS) 20.0 to get the descriptive data as findings of the first phase of the study. The findings of the first phase of this study indicate that the conceptualization level of students in electrochemistry is poor. Multiple alternative frameworks among students were identified from the analysis of the students' responses. This study contributed to existing literature by identifying the alternative frameworks present precisely in electrochemistry. The study recommends incorporating mobile technologies in the data collection process and in developing online instructional modules to be more accessible to educators throughout the country and to steer the chemistry education world to a higher level in the Malaysian education system. Enlightening the alternative framework existent in the students' knowledge schemata immensely facilitates educators worldwide in planning their instructional approach in the classroom for this specific scientific concept. [ABSTRACT FROM AUTHOR]

Obtaining the required surface finish and geometric accuracy together with attaining high production rate is a challenge in finishing of the inner surfaces of steel pipes and bushes. One of the promising techniques for finishing the surface of metal parts is electrochemical machining. In this paper, the surface roughness and dimensional inaccuracy of the inner surface of a CK45 steel bush were controlled electrochemically. For this, a special electrochemical finishing machine was constructed. The effect of electric potential difference along with temperature, flow rate and concentration of electrolyte on the material removal rate, surface roughness and dimensional accuracy were investigated. Box Behnken design (BBD) was used for designing the experiments. Analysis of variance (ANOVA) was performed for validating the experimental models. Also, multi-objective optimization was performed using response surface methodology (RSM) to achieve a predetermined level of surface roughness and dimensional accuracy along with maximizing the material removal rate. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Electrochemistry is the property of Journal of Electrochemistry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

GeFe2O4 (GFO), with its intriguing intercalation mechanism based on alloying–conversion reactions, was recently proposed as an anode material for sodium ion batteries (SIBs). However, drawbacks related to excessive volume expansion during intercalation/deintercalation and poor electronic conductivity enormously hinder its practical application in batteries. In this regard, some experimental strategies such as cation substitutions and proper architectures/carbon coatings can be adopted. In this paper, pure and Mn-doped GFO samples were prepared by hydrothermal synthesis. The doped samples maintained the spinel cubic structure and the morphology of pure GFO. The electrochemical tests of the samples, performed after proper carbon coating, showed the expected redox processes involving both Ge and Fe ions. The Mn doping had a positive effect on the capacity values at a low current density (about 350 mAh/g at C/5 for the Mn 5% doping in comparison to 300 mAh/g for the pure sample). Concerning the cycling stability, the doped samples were able to provide 129 mAh/g (Mn 10%) and 150 mAh/g (Mn 5%) at C/10 after 60 cycles. [ABSTRACT FROM AUTHOR]

Amperometry is arguably the most widely used technique for studying the exocytosis of biological amines. However, the scarcity of human tissues, particularly in the context of neurological diseases, poses a challenge for exocytosis research. Human platelets, which accumulate 90% of blood serotonin, release it through exocytosis. Nevertheless, single-cell amperometry with encapsulated carbon fibers is impractical due to the small size of platelets and the limited number of secretory granules on each platelet. The recent technological improvements in amperometric multi-electrode array (MEA) devices allow simultaneous recordings from several high-performance electrodes. In this paper, we present a comparison of three MEA boron-doped diamond (BDD) devices for studying serotonin exocytosis in human platelets: (i) the BDD-on-glass MEA, (ii) the BDD-on-silicon MEA, and (iii) the BDD on amorphous quartz MEA (BDD-on-quartz MEA). Transparent electrodes offer several advantages for observing living cells, and in the case of platelets, they control activation/aggregation. BDD-on-quartz offers the advantage over previous materials of combining excellent electrochemical properties with transparency for microscopic observation. These devices are opening exciting perspectives for clinical applications. [ABSTRACT FROM AUTHOR]

Thiosullate is considered to be the most promising gold extraction reagent in gold leaching process due to its advantages of non-toxicity and high efficiency. The electrochemical behavior of gold electrode in Cu2+-en-S2 O$_ gold leaching system was investigated by electrochemical testing methods (open circuit potential, cyclic voltammetry, Talel curve and electrochemical impedance). Characterization ol surlace oxidation products ol gold electrodes using Raman spectroscopy and XPS, and the oxidation mechanism ol gold was clarilied. The experimental results show that S2O32- can promote the oxidation ol the gold surface, and under the electrochemical conditions in this paper, the reaction rate is controlled by the step ol charge transfer when the gold electrode is in the 5 mmol/L Cu2+-10 mmol/L en-100 mmol/L S2O32- system. The thiosullate concentration in the system controls the dissolution ol gold by allecting its surlace properties and surlace reaction rate. The electrochemical oxidation mechanism ol gold electrodes in the Cu,十一en-S2O32- leaching gold system was this paper elucidated, and a theoretical basis was provided for the regulation ol the composition ol gold leaching reagents. [ABSTRACT FROM AUTHOR]

The electrolytic refining of crude tin is generally carried out in the fluorosilicic acid (H2SiF6) system with the assistance of bone glue and β-naphthol. However, the high saturated vapor pressure and low stability of H2SiF6 present environmental concerns and do not align with sustainable development goals. In this paper, the electrochemical behavior of tin on a glassy carbon (GC) electrode was studied in a relatively green and environmentally friendly methanesulfonic acid (MSA) system. Bone glue, sodium lignosulfonate, and β-naphthol were used as additives to make the deposit morphology smooth and to ensure grain refinement. The electrochemical reduction process of Sn2+ in an MSA system is a quasi-reversible process controlled by diffusion. The apparent activation energy E a = 14.189 kJ/mol for the ion diffusion of Sn2+ was further calculated. The results of chronoamperometry showed that the electrocrystallization of Sn2+ on the GC electrode gradually tended to three-dimensional instantaneous nucleation with the increase in applied potential. The morphology and phase of the deposits were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the deposits were uniform and dense pure tin. This work elucidates the electrochemical behavior of tin in a methanesulfonic acid system. [ABSTRACT FROM AUTHOR]

The rapid development of early strength of concrete in cold regions is the primary measure to ensure its resistance to frost damage. In this context, this paper incorporates 2 wt% calcium formate into a mortar and electrically cures it by passing an alternating current (AC) at a temperature of −10°C. During testing, a temperature probe monitors the real-time changes in the internal temperature of the mortar under different energisation parameters. The strength of the mortar energised for 1 day is analysed under different energisation parameters. Then, the mortar specimens are moved to a standard curing box to be cured for 3 and 7 days. X-ray diffraction (XRD), TG/DTG (thermogravimetry/derivative thermogravimetry), scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) characterise the hydration products, microstructure and pore structure of the electrically cured mortar specimens. The results show that the initial resistance of the mortar specimen with calcium formate is 25% of that of the mortar without calcium formate. The 3- and 7-day strengths of the calcium formate mortar increase by 59 and 29%, respectively, compared with the mortar without calcium formate under the same energisation parameters. The combined effect of adding calcium formate and applying electrical curing densifies the pore structure of the electrically cured mortar. [ABSTRACT FROM AUTHOR]

Nowadays, research on promoting the dissolution of chalcopyrite is important. As a natural symbiotic mineral of chalcopyrite, arsenopyrite will have an impact on the dissolution of chalcopyrite. This paper shows the influence of arsenopyrite on the dissolution of chalcopyrite in an acidic culture medium. The leaching results showed that adding arsenopyrite increased the leaching concentration of copper by 332 mg/L. The residues showed a decrease in sulfur through X-ray diffraction analysis (XRD) and an increase in dissolution degree through scanning electron microscope (SEM). Electrochemical experiments have shown that the rest potential of arsenopyrite is higher than that of chalcopyrite, so there is a galvanic interaction, and the impact on chalcopyrite is greater than that of arsenopyrite. The polarization curve also proves this. Under the interaction of galvanic couples, the reduction of S0 production and the enhancement of Cu2+ release can promote the dissolution of chalcopyrite. In addition, X-ray photoelectron spectrometer (XPS) analysis under the action of galvanic coupling indicates that more SO42− is generated on the surface of chalcopyrite, replacing Sn2−/S0, and SEM shows a stronger corrosion morphology. All results confirm that the electrochemical effect between arsenopyrite and chalcopyrite promotes the dissolution of chalcopyrite in the acidic culture medium. [ABSTRACT FROM AUTHOR]

The Chemistry Teacher International journal has released a special issue on effective teaching tools and methods to learn about e-waste. This issue is a result of an IUPAC project aimed at providing educational materials and insights for students and teachers in secondary and tertiary education. The special issue focuses on e-waste from a chemical perspective and includes papers written by authors in Brazil, but the experiments and investigations can be performed by students worldwide. The issue is open-access and can be shared widely to inspire educators in developing their own ideas on sustainable chemistry. [Extracted from the article]

The ability of analytical strategies to detect and positively identify molecules under extremely dilute conditions is important for the growth and expansion of analytical techniques and instrumentation. At present, few measurement science techniques can robustly approach the measurement of just a few thousand molecules. Here, we present an electrochemical platform for the detection and positive identification of fewer than 1000 molecules of decamethylferrocene ((Cp*)2FeII). We achieve this remarkable detection threshold by trapping (Cp*)2FeII in a 1,2-dichloroethane microdroplet, which is allowed to dissolve into an aqueous continuous phase while on a gold microelectrode (radius ∼6.25 μm). Because electrochemistry is not sensitive enough to observe the charge of less than 1000 molecules, we dissolved μM amounts hexacyanoferrate(III) in the aqueous continuous phase. The biphasic reaction between hexacyanoferrate(III) and Cp2*(Fe)II allows for a feedback loop when the microelectrode is biased sufficiently negative to reduce Cp2*(Fe)III. This feedback loop, a typical EC′ catalytic mechanism, amplifies the electrochemical signal of Cp2*(Fe)II when the droplet is of small enough dimensions for feedback to occur. Our results demonstrate that clever biphasic reactions can be coupled with dissolving microdroplets to access extremely low limits of quantitation in electroanalysis. [ABSTRACT FROM AUTHOR]

Droplet evaporation and dissolution phenomena are pervasive in both natural and artificial systems, playing crucial roles in various applications. Understanding the intricate processes involved in the evaporation and dissolution of sessile droplets is of paramount importance for applications such as inkjet printing, surface coating, and nanoparticle deposition, etc. In this study, we present a demonstration of electrochemical investigation of the dissolution behaviour in sub-nL droplets down to sub-pL volume. Droplets on an electrode have been studied for decades in the field of electrochemistry to understand the phase transfer of ions at the oil–water interface, accelerated reaction rates in microdroplets, etc. However, the impact of microdroplet dissolution on the redox activity of confined molecules within the droplet has not been explored previously. As a proof-of-principle, we examine the dissolution kinetics of 1,2-dichloroethane droplets (DCE) spiked with 155 μM decamethylferrocene within an aqueous phase on an ultramicroelectrode (r = 6.3 μm). The aqueous phase serves as an infinite sink, enabling the dissolution of DCE droplets while also facilitating convenient electrical contact with the reference/counter electrode (Ag/AgCl 1 M KCl). Through comprehensive voltammetric analysis, we unravel the impact of droplet dissolution on electrochemical response as the droplet reaches minuscule volumes. We validate our experimental findings by finite element modelling, which shows deviations from the experimental results as the droplet accesses negligible volumes, suggesting the presence of complex dissolution modes. [ABSTRACT FROM AUTHOR]

This paper introduces a novel mathematical model for chronoamperometric analysis of electrochemical reactions in the EC2 scheme. Utilizing the homotopy perturbation method, we address the highly nonlinear reaction–diffusion equations, even under non-steady state conditions. We offer an approximate analytical expression for species O and R concentrations, along with sensitivity analysis on diffusion and kinetic parameters. Results under steady state conditions validate our model against prior findings. Additionally, we provide a numerical solution using Matlab and Maple software, demonstrating satisfactory agreement with experimental data. [ABSTRACT FROM AUTHOR]

Introductory chemistry courses at the undergraduate level offer students a foundation in chemistry principles and an opportunity to develop problem-solving skills. These principles and skill sets are widely applicable across disciplines, and thus first year chemistry courses are a gateway for many programs in science, technology, engineering, and mathematics (STEM). While first-year chemistry courses are essential for STEM students, the resulting large-enrollment classes in universities can lead to challenges in implementing active learning and in helping students to reach the course learning outcomes. The evolving field of chemistry education research (CER) offers data and insight for improving teaching and learning strategies at the undergraduate level. We propose and evaluate an electrochemistry team-based problem-solving module as an active learning component of a large, first-year, blended chemistry course. In this paper, we explore the process for developing the module and evaluate this learning approach through focus groups, a large class survey, and student experience interviews. Through a preliminary case study approach, our findings suggest the interactive module is useful for enhancing conceptual understanding and problem-solving in chemistry, and improving academic confidence in electrochemistry learning outcomes. Moreover, students valued their engagement with the team-based problem-solving modules as an opportunity to build community, learn collaboratively, and successfully approach relevant problems. [ABSTRACT FROM AUTHOR]

The contradiction between the migration rate of molecular chains and mechanical strength has always been a key factor affecting the practical application of self‐healing anticorrosion coatings. In this paper, a series of supramolecular self‐healing elastomers (SPU‐MP) were prepared by the reaction of diphenylmethane diisocyanate and polyether amine. The results shown that the proportion of polyetheramine D230 (D230) in molecular segments affects the hydrogen bond density between molecular chains, thereby affecting the self‐healing efficiency and mechanical strength of SPU‐MP. When the ratio of D230 and polyetheramine D400 (D400) is 2:8, the tensile fracture strength of SPU‐MP8 is 5.08 MPa, and the self‐healing efficiency reaches 82.1% after 10 h of repair at room temperature. Further increasing the ratio of D230 increases the relaxation time of the molecular chain due to the increase in hydrogen bond density, resulting in a decrease in the self‐healing efficiency of SPU‐MP. The results of electrochemical experiments and neutral salt spray experiments indicate that the anticorrosion coating prepared by SPU‐MP8 exhibits good self‐healing performance. After immersing in 3.5 wt.% NaCl solution for 35 days, the low‐frequency impedance modulus of the intact coating and the scratch coating were both higher than 107 Ω cm2, still shown good anticorrosion ability. [ABSTRACT FROM AUTHOR]

The traditional Haber-Bosch process for the ammonia synthesis suffers from high energy consumption and severe pollution. Therefore, developing a clean and green synthetic process has been the current research focus. Electrochemical reduction is such a method for nitrogen fixation and ammonia formation, with the core technology lying in how to improve the yield and current efficiency by using proper electrochemical catalysts. Based on literature analysis and summarization, a review was made in this paper on the advances in the ruthenium-based catalysts for the ammonia synthesis, including the synthesis mechanisms from different nitrogen sources, the preparation and modification of ruthenium-based catalysts and their performance. Influence of the catalyst morphology and size on the performance as well as the synergistic effects among ruthenium metal, support, and co-catalysts were also explored, with an aim to provide new perspectives for understanding the ruthenium catalytic process of electrochemical reduction synthesis of ammonia. [ABSTRACT FROM AUTHOR]