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Bulk glass-ceramic solid electrolytes of the Li 2 O–Al 2 O 3 –TiO 2 –P 2 O 5 –SiO 2 system were prepared by melt-quenching and one-step heat treatment method in this work. The effects of the gradual substitution of Al3+ by Cr3+ and the elevation of the heat treatment temperature on the phase composition, microstructure, and ionic conductivity of the solid electrolytes were systematically investigated. The results show that the major crystalline phase is LiTi 2 (PO 4) 3 , and the conductivity of the glass-ceramics initially enhances and then decreases as the Cr 2 O 3 content increases from 0 mol% to 3 mol%. The highest conductivity is obtained when the Cr 2 O 3 content is 2 mol%, measuring 4.45 × 10−4 S/cm at 25 °C. Additionally, the mechanism of the surface exfoliation of the glass-ceramics and the enhancement achieved by doping with Cr3+ are explained according to microstructure analysis. This work provides a simple method to enhance the electrical conductivity and physical properties of LATP glass-ceramic solid electrolytes, which is of great significance for the design of lithium-ion solid electrolytes. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries are promising candidates for large scale energy‐storage due to their combination of inherent security and abundant reserves. The Zn metal undergoes continuous plating and stripping during electrochemical cycling, accompanied by parasitic side reactions and dendrite growth, which severely impedes the commercialization of batteries. Here, an innovative strategy is introduced in electrolyte engineering, dedicated to enhancing the stability at the Zn/electrolyte interface. Theoretical calculations and in situ experimental analyses collectively demonstrate that methyl sulfonyl methane (MSM) additives are beneficial in jointly modulating the hydrogen bonding network and the Zn2+ solvation structure, which in turn restricts H2O activity at the interface. Concurrently, the preferential adsorption of MSM on the Zn surface facilitates the controlled growth of compact zinc layers while suppressing dendritic and parasitic reactions. By modulating the electrolyte and managing the electrode interface, the Zn||Zn symmetric battery can be reversibly cycled over 150 days at a current density of 2 mA cm−2, and the assembled Zn||Cu half‐batteries show impressive cycling stability over 3100 cycles. This study provides an in‐depth comprehension of the Zn2+ plating/stripping behavior, and the development of sophisticated electrolyte systems offers practical guidance for constructing high‐performance zinc‐based batteries. [ABSTRACT FROM AUTHOR]

In order to explore the crystallization behavior of Co‐doped amorphous manganese dioxide(Co‐doped AMO) and to investigate the electrochemical properties of its different crystallization products as cathodes for aqueous zinc ion batteries. In this work, the effects of heat treatment temperature on the microstructure and phase composition of Co‐doped AMO and their electrochemical properties of Zn‐MnO2 battery cathode materials are systematically investigated. The results show that Co‐doping increases the crystallization temperature of pure AMO. When the heat treatment temperature is 400 °C, Co‐doped AMO is amorphous. At 500 and 550 °C, part of the Co‐doped AMO crystallizes into tetragonal spinel structured (Co, Mn)(Co, Mn)2O4 material between MnCo2O4 and Mn3O4. At 650 °C, the crystallized product is completely nano‐α‐Mn(Co)O2 crystal. The maximum discharge specific capacities and the retention rate after 100 cycles of the samples at 100 mA g−1 are 325.40 mAh g−1, 86.88%; 217.00 mAh g−1, 13.94%; 186.68 mAh g−1, 41.01%; and 149.03 mAh g−1, 31.27% for the unheated and 400, 550, 650 °C heat‐treated samples, respectively. It is proved that the Co‐doped AMO without heat treatment is superior to the partially or fully crystallized materials in terms of comprehensive performance and cost as cathode materials for AZIB. [ABSTRACT FROM AUTHOR]

The emergence of Li–Mg hybrid batteries has been receiving attention, owing to their enhanced electrochemical kinetics and reduced overpotential. Nevertheless, the persistent challenge of uneven Mg electrodeposition remains a significant impediment to their practical integration. Herein, we developed an ingenious approach that centered around epitaxial electrocrystallization and meticulously controlled growth of magnesium crystals on a specialized MgMOF substrate. The chosen MgMOF substrate demonstrated a robust affinity for magnesium and showed minimal lattice misfit with Mg, establishing the crucial prerequisites for successful heteroepitaxial electrocrystallization. Moreover, the incorporation of periodic electric fields and successive nanochannels within the MgMOF structure created a spatially confined environment that considerably promoted uniform magnesium nucleation at the molecular scale. Taking inspiration from the "blockchain" concept prevalent in the realm of big data, we seamlessly integrated a conductive polypyrrole framework, acting as a connecting "chain," to interlink the "blocks" comprising the MgMOF cavities. This innovative design significantly amplified charge‐transfer efficiency, thereby increasing overall electrochemical kinetics. The resulting architecture (MgMOF@PPy@CC) served as an exceptional host for heteroepitaxial Mg electrodeposition, showcasing remarkable electrostripping/plating kinetics and excellent cycling performance. Surprisingly, a symmetrical cell incorporating the MgMOF@PPy@CC electrode demonstrated impressive stability even under ultrahigh current density conditions (10 mA cm–2), maintaining operation for an extended 1200 h, surpassing previously reported benchmarks. Significantly, on coupling the MgMOF@PPy@CC anode with a Mo6S8 cathode, the assembled battery showed an extended lifespan of 10,000 cycles at 70 C, with an outstanding capacity retention of 96.23%. This study provides a fresh perspective on the rational design of epitaxial electrocrystallization driven by metal–organic framework (MOF) substrates, paving the way toward the advancement of cutting‐edge batteries. [ABSTRACT FROM AUTHOR]

Copper with equiaxed grains (EG Cu), copper with columnar nanotwinned grains (C‐NT Cu), and copper with mixed equiaxed and columnar grains (MG Cu) are electroplated on pads and redistributed layers (RDLs) with different dimensions. When the diameters of pads increase from 40 to 105 μm, the flatness of pads decreases from 34.5% to 24.0%. The flatness gradually deteriorates from 16.5% to 34.4% with the increase of RDL width from 8 to 20 μm. In contrast, the flatness of C‐NT Cu and MG Cu fluctuates between 1% and 5%, showing a weak correlation on the dimension. In terms of microstructure, the EG Cu and MG Cu has a weak correlation with size change, and the grain orientation shows a randomness. However, the (111) texture component of C‐NT Cu differs greatly with different dimensions, especially in transition layer. The (111) texture component changes from 9.6% to 38.1% for ϕ 40–105 μm pad and from 14.3% to 18.9% for 8–20 μm‐wide RDL. The study reveals the significant size effect on the deposited profile and microstructure of electrodeposited copper materials, which should give insights of the materials design in advanced packaging technology. [ABSTRACT FROM AUTHOR]

The model has been developed for the case of instantaneous nucleation and mixed kinetic-diffusion growth control of new-phase nuclei on the surface of an indifferent electrode under potentiostatic conditions. A new approach has been proposed that does not use the planar diffusion zone concept. The model provides a correct relationship between the concentration profiles to the nucleus and to the electrode due to spherical and planar diffusion, respectively. The influence of charge transfer and mass transfer parameters and the overpotential on the calculated current density transients and the average size of the nuclei has been analyzed. The simulated current density transients have been compared with the results of the calculation according to the Altimari–Pagnanelli and Scharifker–Hills models. The simulation results show that the mutual position of the current density transients under mixed control differs from that under diffusion control. It has been confirmed that the use of the dimensionless dependences of the Scharifker–Hills model at non-pure diffusion growth control can lead to serious errors in determining the mechanisms and electrocrystallization parameters. [ABSTRACT FROM AUTHOR]

Dendrite‐free Zn anode is the key to avoiding battery failure, which is largely determined by the crystal growth during the electrodeposition process. Therefore, controlling the specific crystal orientation growth of Zn is imperative for high‐performing aqueous zinc ion batteries. Herein, an electrocrystallization orientation regulation strategy is proposed to achieve near‐unity stacked Zn (002) texture growth. Featuring the zincophilic nature and high electronegative carboxylate radical, disodium maleate molecules tend to selectively adsorb on the Zn (002) crystal plane, forming a dynamic protection layer. This adsorption layer regulates Zn2+ diffusion along [100] and [101] orientations with the lowest deposition rate on the (002) plane, homogenizes Zn2+ flux, and keeps away water from Zn surface, constructing the flattened and horizontally arranged Zn deposition layer with dominantly Zn (002) texture and inhibited side‐reaction. Consequently, the Zn anode with near‐unity stacked (002) texture exhibits a 40‐fold enhancement in running lifetime beyond 3200 h and improved coulombic efficiency of 99.81% over 3000 cycles than that with bare ZnSO4 electrolyte. Even at harsh plating/stripping conditions of 30 and 30 mAh cm−2, the Zn anode still sustains state‐of‐the‐art stability over 120 h, enabling a substantial advance in the long‐term stability of the battery. [ABSTRACT FROM AUTHOR]

This study investigates the effect of different concentrations of lanthanum chloride on the grain refinement of cobalt deposition layers during the electrochemical deposition process in industrial electrolytes. The impact of different lanthanum chloride concentrations on cobalt electrodeposition behavior was analyzed using the Liner sweep voltammetry curve, cyclic voltammetry curve, and chronoamperometry curve. The microstructure morphology and grain size of the deposition layers were analyzed using scanning electron microscopy and atomic force microscopy and the preferred orientation and crystal structure were analyzed using X-ray diffraction. The results show that the addition of different concentrations of lanthanum chloride to the industrial electrolyte leads to a negative shift in the starting deposition potential of cobalt, an increase in cathode polarization degree, an increase in overpotential, a shortened nucleation relaxation time, and an accelerated nucleation rate during cobalt electrodeposition, resulting in grain refinement of the deposition layers. However, the addition of lanthanum chloride does not change the cobalt electrocrystallization mechanism, nor does it alter the crystal structure of the cobalt deposition layers, which remain in a close-packed hexagonal structure. When 0.2-g L−1 lanthanum chloride is added, the grain growth orientation changes from the (11 2 ¯ 0) plane to the (11 2 ¯ 0) and (10 1 ¯ 0) planes, resulting in a uniform distribution of grain size and obvious grain refinement of the deposition layers. [ABSTRACT FROM AUTHOR]

Electrocrystallization is a promising method for controlled charge‐transfer complex (CTC) deposition on microfabricated electrodes for gas sensing applications. However, there remains a gap in our understanding of CTC electrodeposition. In this study, we focus on investigating the electrocrystallization of cobalt tetracyanoquinodimethane (Co‐TCNQ) on a microdisk electrode to elucidate and control the process. Leveraging the microelectrode technique, we conduct steady‐state measurements to observe nucleation and crystal growth dynamics, particularly in the early stages of electrocrystallization. We use cyclic voltammetry and chronoamperometry to examine Co‐TCNQ electrocrystallization under various electrolytic conditions. We identify electrocrystallization kinetics, ranging from electrokinetic to diffusion‐limited growth, governing the nucleation and growth of Co‐TCNQ crystals. Notably, we pinpoint the applied overpotential and precursor concentration range necessary for a single nucleation site on the microelectrode. Moreover, we demonstrate control over crystal orientation and morphology. Our findings reveal a nonclassical growth pathway for Co‐TCNQ crystals characterized by oriented attachment of small crystallites along the conductive long axis. Importantly, electrodeposited Co‐TCNQ on patterned microelectrodes exhibits selective sensing capabilities for nitrogen dioxide gas. Overall, this study sheds light on CTC electrodeposition through a proof‐of‐concept demonstration involving Co‐TCNQ electrodeposition on microelectrodes, presenting potential applications across diverse materials. [ABSTRACT FROM AUTHOR]

At the electrochemical deposition of alloys various phenomena are observed that lead to changes in the kinetics and thermodynamics of the processes. In particular, as a result of changing in the nature of the electrode surface, both the exchange current densities and the transfer coefficients of each of the components changed. Further, during the formation of solid solutions, the equilibrium potentials of the components change due to the non-zero enthalpy and entropy of mixing. At the deposition of eutectic-type alloys (that is, a mixture of grains of individual components), each of the metals does not deposit on the entire electrode surface but only on its own surface. In the latter case, there is a change in the diffusion pattern of the components as compared to the deposition of individual metals: it remains unchanged in the outer part of the diffusion layer but there is a condensation of the diffusion fields of the components near the surface, similar to the case of diffusion to the matrix of microelectrodes or to individual nuclei of a new phase. This also leads to a change in the diffusion part of the overpotential of the components' deposition. The diffusion of ions of the discharging negative component of an alloy representing a mechanical mixture of the metals' A and B grains to the grain surface of this component in the model of a partially blocked electrode is considered. At a constant potential, the local current density of the component is shown to increase as a result of the diffusion acceleration. The magnitude of the relative increase in the current and the corresponding magnitude of apparent depolarization are found, as compared between the deposition of an individual metal and the codeposition of the same component into an alloy. [ABSTRACT FROM AUTHOR]

The waste lithium cobalt acid batteries were utilized as raw materials to separate out LiCoO2 cathode material. Citric acid was used to leach cathode material, and LiCoO2 leaching solution was electrodeposited to obtain cobalt plating, in the meantime the Li2+ ions were enriched. The optimized conditions of leaching process are 1,2 mol/L citric concentration and 0,35 mol/L sodium thiosulfate concertation, the leaching efficiency of cobalt and lithium is 97,5 % and 97,0 % respectively. At pH 4, the smooth cobalt coating with fine grains can be obtained on the surface of the stainless-steel cathode.

Copper coatings with refined grains and smooth surface morphology were electrodeposited from electrolytes comprising a novel accelerator, the disodium salt of 4,4-dithiobenzene disulfonic acid (DBDA), with sodium chloride and polyethylene glycol (PEG) as inhibitors and 2-aminobenzothiazole (ABT) as a leveler. It was found that the morphology of the coatings strongly depends on the presence and type of additives. In the presence of only DBDA and NaCl, large crystallites are formed, whereas the addition of PEG and ABT significantly decreases their size, and the most fine-grained, smooth, and defect-free copper coating is formed with the combined use of all additives. To establish the correlation between the observed morphology and the kinetics of the additive-assisted copper electrocrystallization in the proposed electrolytes, the nucleation mechanism and its parameters were determined by transient electrochemical characterization. The extended nucleation model, which takes into account not only the copper deposition but also the electric double-layer charging and hydrogen reduction process, was used to establish the electrocrystallization kinetics in the presence of the additives. The results of such kinetic analyses can help to explain the morphological effect. By using the chronopotentiometry method, it was found that the addition of the disodium salt of 4,4-dithiobenzene disulfonic acid with chloride ions gives a catalytic effect, while the sequential introduction of polyethylene glycol and 2-aminobenzothiazole provides an increasing inhibitory effect. Voltamperometry and chronoamperometry tests showed that the process is controlled by the diffusion of ions to the growing three-dimensional cluster of a new phase. The introduction of additives into the electrolyte slows down the copper electroplating process at comparatively negative potentials and increases the probability of transition from instantaneous to progressive nucleation. Moreover, the rate of the process and the density of nucleation active sites increase (up to 2–3 times) with the addition of DBDA but decrease significantly (up to 5–8 times) in the presence of PEG and ABT, which additionally confirms their catalytic and inhibitory effects, respectively, and explains the significant smoothing effect on the morphology of the Cu-coatings. [ABSTRACT FROM AUTHOR]

Controlling lithium (Li) electrocrystallization with preferred orientation is a promising strategy to realize highly reversible Li metal batteries (LMBs) but lack of facile regulation methods. Herein, we report a high‐flux solid electrolyte interphase (SEI) strategy to direct (110) preferred Li deposition even on (200)‐orientated Li substrate. Bravais rule and Curie‐Wulff principle are expanded in Li electrocrystallization process to decouple the relationship between SEI engineering and preferred crystal orientation. Multi‐spectroscopic techniques combined with dynamics analysis reveal that the high‐flux CF3Si(CH3)3 (F3) induced SEI (F3‐SEI) with high LiF and −Si(CH3)3 contents can ingeniously accelerate Li+ transport dynamics and ensure the sufficient Li+ concentration below SEI to direct Li (110) orientation. The induced Li (110) can in turn further promote the surface migration of Li atoms to avoid tip aggregation, resulting in a planar, dendrite‐free morphology of Li. As a result, our F3‐SEI enables ultra‐long stability of Li||Li symmetrical cells for more than 336 days. Furthermore, F3‐SEI modified Li can significantly enhance the cycle life of Li||LiFePO4 and Li||NCM811 coin and pouch full cells in practical conditions. Our crystallographic strategy for Li dendrite suppression paves a path to achieve reliable LMBs and may provide guidance for the preferred orientation of other metal crystals. [ABSTRACT FROM AUTHOR]

A new molecular conductor, i.e., κ-(BEDT-TTF)2K+(18-crown-6)[CoII(NCS)4]∙(H2O), is semiconductive with substantial charge gap values (ΔE) of 0.57 eV (measured) and 0.37 eV (calculated). There is a full band separation despite formal average charge on BEDT-TTF of +0.5 and κ(kappa)-type packing of BEDT-TTF dimers that favors high conductivity. X-ray crystal structure analysis reveals complete charge ordering with full Coulomb charge on unique BEDT-TTF radical cations A (QA = +1), while unique molecules B are uncharged (QB = 0). Geometries of A (flat) and B (bent) differ considerably and are in accordance with the ascribing charges. Charge segregation is enhanced by forming tight face-to-face BEDT-TTF dimers AA (QAA = +2) and BB (QBB = 0). Strongly interacting double-charged dimers AA form "superstripes" running along a that are interleaved along b with chains of neutral dimers BB. Peculiar extremely thick (13.7 Å) four-decker insulating anion layers cast strong Coulomb potential onto the conductive layers predetermining charge localization in the latter. [ABSTRACT FROM AUTHOR]

On the assumption of the mixed kinetics of the process, new formulas are derived for the calculating of the diffusion coefficient, the nucleation rate, and the number of growing clusters, basing on the experimental curves of the time dependence of the current during the potentiostatic nucleation and growth in the electrocrystallization process. In this context, some literature experimental data are analyzed. It is shown that during crystallization on an active metal substrate, the number of nuclei can sharply increase with potential, unlike structureless substrates (such as glassy carbon) at which the nuclei number depends but weakly on the potential. [ABSTRACT FROM AUTHOR]

A method is proposed for analytical description of current transients at the template-assisted electrodeposition of metal into porous films in anodic aluminum oxide (AAO). The template-assisted electrodeposition of copper and gold is accomplished. For the copper electrodeposition, it is shown that the experimental data are in quantitative agreement with the calculated values of current without any fitting parameters. The parameters of the AAO film structure including the conicity of pores and the number of dead-end channels are measured and their effect on the process of template-assisted electrodeposition is studied. [ABSTRACT FROM AUTHOR]

Elucidating the underlying mechanisms of water solidification in heterogeneous systems is crucially important for a panoply of applications; gaining such an understanding has also proven to be very challenging to the community. Indeed, one such example lies in clarifying the thermodynamics and kinetics of electro-crystallization in heterogeneous systems, such as micro- and nano-bubble systems. Here, we employ non-equilibrium molecular dynamics of water in heterogeneous environments experiencing direct contact with a propane gas phase at various temperatures in externally applied static electric fields, elucidating significant external-field effects in inducing poly-crystalline cubic-ice formation. This is in stark contrast with recent work on homogeneous cubic-ice electro-nucleation to produce largely fault-free single crystals. We explore the kinetics of heterogeneous cubic-ice electro-nucleation under different field intensities and thermal conditions and provide an overview of time-dependent dynamics of evolution of polycrystallinity. [ABSTRACT FROM AUTHOR]

Resistive switching devices based on transition metal oxides require formation of a conductive filament in order for the device to be able to switch. Such filaments have been proposed to form by the reduction of oxide due to the application of the electric field, but this report seeks to rebut that interpretation. Frequently reported physical changes during electro-formation include delamination of electrodes, crystallization of functional oxide, intermixing of electrode and oxide materials, and extensive loss of oxygen presumably to the ambient. Here, we show that most of these effects are not inherent to the formation and switching processes and instead are due to an experimental artifact: the discharge of parasitic capacitances in the forming circuit. Discharge of typical BNC cables can raise the temperature of the filament to between 2000 and 5000 K resulting in extensive physical changes. Discharge and associated effects mentioned above can be eliminated using an on-chip load element without affecting the ability to switch. [ABSTRACT FROM AUTHOR]

The lack of understanding for precise synthesis and assembly of nano‐entities remains a major challenge for nanofabrication. Electrocrystallization of a charge‐transfer complex (CTC), tetrathiafulvalene bromide (TTF)Br, is studied on micro/nanoelectrodes for precision deposition of functional materials. The study reveals new insights into the entire CTC electrocrystallization process from the initial nanocluster nucleation to the final elongated crystals with hollow ends grown from the working electrode to the neighboring receiving electrode. On microelectrodes, the number of nucleation sites is reduced to one by lowering the applied overpotential or precursor concentration. Certain current–time transients exhibit significant induction periods prior to stable nucleus growth. The induction regime contains small fluctuating current spikes consistent with stochastic formation of precritical nanoclusters with lifetimes of 0.1–30 s and sizes of 20–160 nm. Electrochemical analyses further reveal rate, size distribution, and formation/dissipation dynamics of the nanoclusters. Crystal growth of (TTF)Br is further studied on triangular nanoelectrode patterns with thickness of 5–500 nm, which shows a mass‐transfer‐controlled process applicable for precision deposition of functional (TTF)Br crystals. This study, for the first time, establishes CTC nanoelectrochemistry as a platform technology for precise deposition of conductive crystal assemblies spanning the source and drain electrode for sensing applications. [ABSTRACT FROM AUTHOR]

Realizing durative flattened and dendrite‐free zinc (Zn) metal configuration is the key to resolving premature battery failure caused by the internal short circuit, which is highly determined by the crystal growth in the electrocrystallization process. Herein, we report that regulating the molecular structure of the inner Helmholtz plane (HIP) can effectively convert the deposition into activation control by weakening the solvated ion adsorption at the interface. The moderated electrochemical reaction kinetics lower than the adatom self‐diffusion rate steers conformal stratiform Zn growth and dominant Zn (0001) texture, achieving crystallographic optimization. Through in situ mediation of electrolyte engineering, orientational plating and stripping behaviors at edge‐sites and tailored solvation structure immensely improve the utilization efficiency and total charge passed of Zn metal, even under extreme conditions, including high areal capacity (3 mAh cm−2) and wide temperature range (−40–60 °C). [ABSTRACT FROM AUTHOR]

A sequencing batch two chamber electrolysis cell was set up to recover phosphate(P) from synthetic wastewater containing KH2PO4 with different gradients.In the cell, ferrous iron goes into the liquor from iron‐anode to precipitate soluble P and form vivianite.The two‐chamber electrolytic cell provides a suitable pH range for the formation of vivianite without adding acid and alkali, which saves costs and avoids waste of resources. After repeated experiments with different gradients, the minimum phosphorus(P) removal efficiency was stably achieved at 97.17 %. After long‐term operation, the P removal effect was not affected despite the fouling of the proton exchange membrane(PEM). Further analysis by XRD, FITR and SEM illustrated that the P recovery precipitated was vivianite. [ABSTRACT FROM AUTHOR]

A new molecular conductor, i.e., κ-(BEDT-TTF)2K+(18-crown-6)[CoII(NCS)4]∙(H2O), is semiconductive with substantial charge gap values (ΔE) of 0.57 eV (measured) and 0.37 eV (calculated). There is a full band separation despite formal average charge on BEDT-TTF of +0.5 and κ(kappa)-type packing of BEDT-TTF dimers that favors high conductivity. X-ray crystal structure analysis reveals complete charge ordering with full Coulomb charge on unique BEDT-TTF radical cations A (QA = +1), while unique molecules B are uncharged (QB = 0). Geometries of A (flat) and B (bent) differ considerably and are in accordance with the ascribing charges. Charge segregation is enhanced by forming tight face-to-face BEDT-TTF dimers AA (QAA = +2) and BB (QBB = 0). Strongly interacting double-charged dimers AA form “superstripes” running along a that are interleaved along b with chains of neutral dimers BB. Peculiar extremely thick (13.7 Å) four-decker insulating anion layers cast strong Coulomb potential onto the conductive layers predetermining charge localization in the latter.

Downstream processing of biotechnologically produced carboxylic acids, such as succinic acid, poses environmental and economic challenges. Conventional downstream processes cause large amounts of waste salts, which have to be purified or disposed of. Therefore, lean and waste-free downstream processes are necessary for the biotechnological production of succinic acid. Electrochemical downstream processes gain especially significant attention due to low chemical consumption and waste reduction. This work presents the pH-dependent solid-liquid equilibrium of succinic acid, a prototype for electrochemical pH-shift crystallization processes, and its characterization. Based on the supersaturation, energy consumption, and electrochemical protonation efficiency the proposed electrochemical pH-shift crystallization is evaluated. This evaluation highlights the potential of the proposed electrochemical crystallization processes as waste-free and economically attractive processes for bio-based succinic acid production. [ABSTRACT FROM AUTHOR]

Silver inverse opals were prepared electrochemically using non-toxic water–ethanol rhodanic and sulfite electrolytes for silver plating. Electrochemical crystallization of silver occurred in the pores of opal matrices made of 350 nm polystyrene microspheres. Samples with the most uniform structure and lowest percentage of surface admixtures were obtained from rhodanic electrolytes. Reflectance optical spectra of the silver inverse opals with a high surface periodicity showed various plasmon excitation modes in a visible spectral range making the silver opals attractive for plasmonics. [ABSTRACT FROM AUTHOR]

The management of hypersaline brine is a critical challenge to achieving a circular water economy. Traditional brine treatment technologies mainly rely on thermal evaporation, which requires intensive energy, cost, and/or areal footprint. Electrodialytic crystallization (EDC) has been recently developed as a novel process that enables brine crystallization without evaporation. However, the potential effects of mineral scaling and organic fouling on the performance of EDC have not been revealed. In this study, we systematically investigated mineral scaling and organic fouling in EDC. We demonstrate that the ion transport and crystallization efficiencies of EDC are generally unaffected by a variety of mineral scalants and organic foulants, despite an increase of energy consumption in the presence of humic acid. Further, EDC is shown to be less susceptible to gypsum scaling than RO, mainly due to the difference in concentration polarization between these two membrane processes. To mitigate gypsum scaling in an assumptive EDC-RO treatment train towards zero liquid discharge (ZLD), polyacrylic acid (PAA) is employed as an antiscalant that prevents gypsum scaling in RO while not adversely affecting EDC performance at relatively low concentration. Our study unravels the behaviors of EDC when treating feedwater with high scaling and fouling potentials, providing valuable insights for understanding mineral scaling and organic fouling when applying an ED-based technology for hypersaline brine treatment towards ZLD. [Display omitted] • The effects of membrane scaling and fouling on EDC performance are explored. • EDC performance is generally unaffected by a variety of mineral scalants and organic foulants. • The presence of humic acid increases energy consumption of EDC. • EDC is less susceptible to gypsum scaling than RO within an integrated treatment train. • Antiscalant PAA can mitigate gypsum scaling in RO without adversely affecting EDC performance. [ABSTRACT FROM AUTHOR]

The benign electrochemical technologies are the promising methods for the reuse of reverse osmosis concentrate (ROC) by softening and removing silica, whereas its low treatment performance and high energy consumption limit its wide industrial application. In this study, an undivided electrochemical crystallization cell with the extraction of acid anode boundary layer was developed for the production of the alkaline effluent, where the removal of hardness and silica occurred by the homogeneous crystallization reactions. This process was further improved in the electrocoagulation cell because coagulants enhance the removal of crystalline particles and accelerate the settling of the crystals. Under optimal conditions, the system showed a removal efficiency of 90 % for total hardness, 76 % for Mg hardness, and 82 % for silica, with an energy consumption of only 2.4 kWh m−3. The removal of Ca hardness in the forms of calcite and aragonite was impeded by the presence of Mg2+. But the coexistence of silica promoted Ca hardness removal since the reaction between Mg2+ and silica with the formation of sepiolite mitigated the inhibitory effect of Mg2+ on CaCO 3 precipitation. The coupled electrochemical crystallization-electrocoagulation-flocculation technique provides an energy-efficient solution for the removal of hardness and silica from ROC, therefore improving the water utilization in industry. [Display omitted] • The electrochemical coupled system enabled effective softening and silica removal. • By extracting the anode boundary layer, both acidic and alkaline effluents can be generated. • Flocculants in electrocoagulation cell removed silica and accelerated precipitation. • Removing 90 % hardness and 82 % silica in the coupled system consumed as low as 2.4 kWh m−3. • Magnesium silicate formation mitigated the inhibition of CaCO 3 crystallization induced by Mg2+. [ABSTRACT FROM AUTHOR]

The lattice‐oxygen‐mediated mechanism is considered as a reasonable mechanism for the electrochemical catalytic oxygen evolution reaction (OER) of NiFe layered double hydroxides (LDHs). A NiFe LDH with distinct lattice contraction and microcrystallization was synthesized via a simple one‐step method using sodium gluconate. The lattice contraction is attributed to the interaction of carbon in sodium gluconate and iron in NiFe LDH. The NiFe LDH with optimized microcrystallization and lattice contraction shows a low overpotential of 217 mV at a current density of 10 mA cm−2 and excellent durability of 20 h at a high current density of 100 mA cm−2. The results revealed that a contractive metal–oxygen bond could boost the intrinsic activity of active sites and the microcrystallization promotes an increase in the number of active sites in terms of unit area. The chemical environment of oxygen elemental characterization and resistance at different chronopotentiometry times confirm that the lattice oxygen element is indeed involved in the process of OER, supporting the lattice‐oxygen‐mediated mechanism of NiFe LDH. Density functional theory calculations reveal that contractive metal–oxygen bonds induced a reduction of the adsorption energy barrier of intermediate products, thus improving the intrinsic catalytic activity. The special characteristics of microcrystallization and lattice contraction of NiFe LDH provide a strategy to improve both the number and the intrinsic activity of active sites in a versatile manner. [ABSTRACT FROM AUTHOR]

A new equation for calculating the number of atoms in a critical nanocluster, which is suitable for the case of metal electrocrystallization, is derived. The equation takes into account the Tolman size factor (the dependence of specific surface energy on the cluster size) and/or the surface energy gradient, that is, the effect of subsurface atomic layers. At small overvoltages, the equation takes the classical form. [ABSTRACT FROM AUTHOR]

A brief review is given on the current transition of the electrodeposition of materials by a mechanism of nucleation followed by diffusion-controlled growth. A short historical background to study the nucleation and growth by diffusion-controlled electrocrystallization is provided. Then, an outline of the major potentiostatic current transient modeling is given, with some comments on their relative merits. Finally, a summary of the current transition functions of nucleation and growth under diffusion-controlled electrocrystallization is given including the theoretical models that have been recently applied. [ABSTRACT FROM AUTHOR]

Strain-induced self-folding is a ubiquitous phenomenon in biology, but is rarely seen in brittle geological or synthetic inorganic materials. We here apply this concept for the preparation of three-dimensional free-standing microscrolls of cobalt hydroxide. Electrodeposition in the presence of structure-directing water-soluble polyelectrolytes interfering with solid precipitation is used to generate thin polymer/inorganic hybrid films, which undergo self-rolling upon drying. Mechanistically, we propose that heterogeneities with respect to the nanostructural motifs along the surface normal direction lead to substantial internal strain. A non-uniform response to the release of water then results in a bending motion of the two-dimensional Co(OH)2 layer accompanied by dewetting from the substrate. Pseudomorphic conversion into Co3O4 affords the possibility to generate hierarchically structured solids with inherent catalytic activity. Hence, we present an electrochemically controllable precipitation system, in which the biological concepts of organic matrix-directed mineralization and strain-induced self-rolling are combined and translated into a functional material. [ABSTRACT FROM AUTHOR]

Isotactic polybutene-1 (iPB-1) generally crystallizes into metastable form II upon non-isothermal crystallization from the melt. The inevitable and prolonged transition of this form to form I is a drawback of numerous iPB-1 applications. In this study, electrospun (e-spun) membranes and solution cast films were prepared from the same solution, but they exhibited different crystalline behaviors. The fresh e-spun and solution cast samples contained hexagonal form I/I′ and tetragonal II, but the former was dominant in the e-spun samples. This finding was attributed to the stress-induced crystallization during electrospinning. The e-spun blend membrane of iPB-1/isotactic polypropylene (iPP) (75/25) was investigated via time-based heating-cooling protocols to obtain a stable form I′ exclusively. Upon annealing the findings revealed a distinct amount of form I′ for the e-spun blend at a quenching value of −25 °C, wherein metastable form II was suppressed entirely. The results indicate that form I′ generation in both types of samples is characterized by a confined nucleation mechanism, but in e-spun iPB-1/iPP membranes, the malleable structure favors the thermodynamics characteristics of form I′ upon heating which also reinforces the transition kinetics. The amount of form I′ was found to be directly proportional to the heating time at 185 °C, whereas it was inversely proportional to the quenching and crystallization temperatures. [ABSTRACT FROM AUTHOR]

The formation of tin dendritic nanostructures by electrolysis from the alkaline electrolyte has been investigated. Morphology and structure of Sn dendrites produced applying both potentiostatic and galvanostatic regimes of the electrolysis are characterized by SEM and XRD, respectively. Depending on the applied cathodic potentials, three types of Sn dendrites were obtained: (a) needle-like and spear-like, (b) fern-like, and (c) stem-like dendrites. The very branchy dendrites with branches of the prismatic shape obtained by the galvanostatic regime of electrolysis represented a novel type of Sn dendrites, not previously reported in the literature. To explain the formation of various dendritic forms, correlation with the polarization characteristics for this electrodeposition system is considered. The needle-like and the spear-like dendrites represented monocrystals of (200),(400) preferred orientation, the fern-like dendrites exhibited the predominant (220),(440) preferred orientation, while in the stem-like particles Sn crystallites were oriented to a greater extent in the (440) crystal plane than in other planes. The galvanostatically synthesized Sn particles possessed the strong (200),(400) preferred orientation. The strong influence of parameters and regimes of electrodeposition on structural characteristics of Sn dendrites is explained by the fundamental laws of electrocrystallization taking into consideration the concept of slow-growing and fast-growing crystal planes. [ABSTRACT FROM AUTHOR]

The dependences of the strength properties of "pure" electrochemical iron and iron-alloy-based coatings on the parameters of their substructure characterized by the density of electrolytic iron are found. The region of their hardening due to substructural changes is shown to be limited and to correspond to the transition of a metal structure to the "ultimate deformation" state, which is characterized by the appearance of submicrocracks and a decrease in the strength properties of the formed coatings. [ABSTRACT FROM AUTHOR]

The magnetic field-assisted electrodeposition of iron–nickel thin films on different substrates (aluminum, silver, and brass) was investigated. The process was performed galvanostatically in a sulfate solution. The same chemical and electrical conditions were applied for each sample growth, but the time restrictions and the external magnetic field orientation were changeable. The obtained results show a variation of surface morphology and composition dependence on the selected surfaces as a consequence of the presence and orientation of the external magnetic field. We discussed that the FeNi crystal structure depends on the film thickness. The results show the reduction of the film thickness after the external magnetic field application—a decrease of deposition rate.The FeNi alloy's morphology, composition, and magnetic properties were investigated by scanning electron microscopy (SEM), X-ray diffraction, energy dispersive X-ray spectroscopy (EDX), and Mössbauer spectroscopy (MS). [ABSTRACT FROM AUTHOR]

The problem of diffusion-controlled growth following an instantaneous nucleation event was studied within the framework of a new numerical model, considering the spatial distribution of hemispherical nuclei on the electrode surface and the mutual influence of growing nuclei via the collision of 3D diffusion fields. The simulation of the diffusion-controlled growth of hexagonal and random ensembles was performed at the overpotential-dependent number density of nuclei. The diffusion flow to each nucleus within a random ensemble was simulated by the finite difference method using the derived analytical expressions for the surface areas and the volumes formed at the intersection of 3D diffusion fields with the side faces of a virtual right prism with a Voronoi polygon base. The implementation of this approach provides an accurate calculation of concentration profiles, time dependences of the size of nuclei, and current transients. The results, including total current density transients, growth exponents, and nucleus size distribution, were compared with models developed within the concept of planar diffusion zones, the mean-field approximation and the Brownian dynamics simulation method, as well as with experimental data from the literature. The prospects of the model for studying the initial stages of electrocrystallization were discussed. [ABSTRACT FROM AUTHOR]

Elemental doping is an effective strategy to overcome the degradation of the rate performance of cobalt-free layered cathode materials, which is attributable to the absence of cobalt. This study focuses on the implementation of a modified doping strategy, which entails in-situ coprecipitation to introduce 0.3 mol% Zr4+ as a dopant to these cathode materials. This approach enabled us to confirm that in-situ Zr4+ doping significantly impacted the crystallization behavior and electrochemical properties of these materials and this effect is not negligible. In particular, in-situ Zr4+ doping increased the crystallization temperature of the materials and broadened the spacing between the lithium layers while maintaining the original crystal configuration. The doped sample had the best cycling stability at the crystallization temperature of 800 °C (capacity retention of 80.03% after 200 cycles at the 1 C rate) and rate performance (discharge specific capacity of up to 161.6 mAh g−1 at the 5 C rate), whereas the original (undoped) sample delivered the best electrochemical performance at 780 °C (capacity retention of 74.29% after 200 cycles at the 1 C rate and discharge capacity at the 5 C rate of 154.57 mAh g−1). • The in-situ method successfully achieved uniform Zr–doping in the bulk phase of NM. • In-situ Zr4+ doping has a significant influence on the crystallization process behavior. • In-situ Zr4+ doping further enhanced the cyclic stability and rate performance of NM. [ABSTRACT FROM AUTHOR]

• Specific adsorption of acetate stabilizes the Cu UPD monolayer on Au(111). • Three distinct UPD processes are identified for Cu on Au(111) by cyclic voltammetry. • After completion of the UPD monolayer, both Cu dissolution and Cu bulk deposition are kinetically hindered, each with an overpotential of 0.3 V. • The strong adsorption of acetate on the Cu UPD monolayer is supposed to be related to these kinetic hindrances observed in the experiment. • As in the case of chloride and sulfate, (surface) alloying of Au with Cu is observed also in the presence of acetate. The underpotential deposition (UPD) of Cu on Au(111) in the presence of acetate is investigated by cyclic voltammetry, potential step experiments, and in-situ STM imaging. The specific adsorption of acetate stabilizes the UPD monolayer (ML) of Cu on Au(111). Three distinct deposition processes are identified by cyclic voltammetry. The first two deposition processes corresponding to Cu sub-monolayer coverages are reversible. Strong kinetic effects arise for higher Cu coverage during the deposition and dissolution, which gradually lower the reversibility of the electrocrystallization process. Dissolution of the full Cu monolayer is shifted positively by about 0.3 V. In addition, bulk deposition is kinetically hindered for an extended potential region. The acetate coverage on the complete Cu monolayer is estimated to be 0.2–0.3 ML. It is proposed that adsorbed acetate on the Cu UPD ML is related to the kinetic hindrance observed in the experiments. (Surface) alloying of Cu and Au is observed by cyclic voltammetry and in-situ STM. [Display omitted] [ABSTRACT FROM AUTHOR]

• MFES system has achieved membrane-free efficient separation of H + and OH−. • The pH of the pump suction water can increase from 8.13 to 11.42 within 10 min. • FC system can reduce the time required for homogeneous precipitation. • The single-pass removal rates for total hardness and alkalinity reached 92 % and 67 %. The traditional electrochemical descaling process exhibits drawbacks, including low OH− utilization efficiency, constrained cathode deposition area, and protracted homogeneous precipitation time. Consequently, this study introduces a novel membrane-free electrochemical separation-filtering crystallization (MFES-FC) coupling process to treat circulating cooling water (CCW). In the membrane-free electrochemical separation (MFES) system, OH− is rapidly extracted by pump suction from the porous cathode boundary layer solution, preventing neutralization with H +, thereby enhancing the removal of Ca2+ and Mg2+. Experimental results indicate that the pH of the pump suction water can swiftly increase from 8.13 to 11.42 within 10 min. Owing to the high supersaturation of the pump suction water, this study couples the MFES with a filtration crystallization (FC) system that employs activated carbon as the medium. This approach captures scale particles to enhance water quality and expedites the homogeneous precipitation of hardness ions, shortening the treatment time while further augmenting the removal rate. After the MFES-FC treatment, the single-pass removal rates for total hardness, Ca2+ hardness, Mg2+ hardness, and alkalinity in the effluent reached 92 %, 97 %, 64 %, and 67 %, respectively, with turbidity of 3 NTU, current efficiency of 86.6 %, and energy consumption of 7.19 kWh·kg−1 CaCO 3. This coupling process facilitates an effective removal of hardness and alkalinity at a comparatively low cost, offering a new reference and inspiration for advancements in electrochemical descaling technology. [Display omitted] [ABSTRACT FROM AUTHOR]

The influence of glycine, as a chelating agent, and triblock copolymer mixture of PPG-PEG-PPG and PEG1000, as a suppressor agent, on the deposition mechanisms of zinc and zinc-nickel alloys were studied by cyclic voltammetry (CV) and potentiometric electrochemical impedance spectroscopy (PEIS), using electrolyte solutions of chlorinated acid. Cyclic voltammetry measurements show that the composition of the electrolytic solution affects the voltammogram profiles. Complementary PEIS investigations allowed the electrodeposition mechanisms to be highlighted depending on the composition of the electrolytic solution. The electrodeposition of zinc, in the absence of additives, occurs in a single cathodic wave from the ZnCl 3 − species, whereas in the presence of glycine, a second more cathodic reduction wave is relative to the Zn(Gly) 2 2+ species. The presence of the PPG-PEG-PPG and PEG1000 triblock copolymer induces a clear inhibition of the zinc reduction. Nevertheless, the zinc electrodeposition follows a three-dimensional instantaneous nucleation. The zinc electroplating mechanism involves a capacitive semi-circle at high frequency and two inductive loops at medium and low frequencies assigned to two adsorbed intermediates onto the substrate whatever the electrolyte composition. The presence of the polymer mixture affects the zinc reduction by increasing the charge-transfer resistance and the adsorption phenomena on the substrate. The electrodeposition of zinc-nickel alloys reveals a single reduction wave, from ZnCl 3 − and Ni(Gly)2+ species, and multiple anodic signals depending on the electrolytic composition, according to the presence of glycine to chelate the nickel species. The zinc-nickel electroplating was evidenced to be a multiple-step process with a three-dimensional instantaneous nucleation, including intermediate species adsorbed onto the substrate. The equivalent circuit proposed consists of two capacitive half-circles separated by an inductive loop for any electrolytic solution. However, the impedance spectra were affected by the presence of glycine by modifying the inductive loop reflecting the first adsorbed intermediate (Ni(I) ads). The morphology of zinc and zinc-nickel, with a nickel content between 14 and 19 wt%, is affected by the electrolyte composition, however with the same crystal lattice. The preferential orientation of the lattice was shown to depend on the additives present in the solution. [ABSTRACT FROM AUTHOR]

In this study, core‐shell structured nanofibers (P/E/@IL), in which the blend of poly(ethylene oxide) (PEO) and ionic liquid (IL) acted as core and poly(vinylidene fluoride) (PVDF) acted as shell layer, were prepared by coaxial electrospinning in order to explore the effect of PEO crystallization on the ionic conductivity and dielectric property. For comparison, the blended spinning fibers of PVDF, PEO, and IL (abbreviated as P/E/IL) were also fabricated. It can be observed that the incorporation of IL dramatically improves the dielectric constant (ε′) of P/E/@IL composites. However, the tan δ also exhibits a sharp increase with increasing content of IL due to the ion conduction, whereas compared with blended films, the PEO and IL in the core layer exhibit a more positive effect on suppressing the tan δ of film via PEO crystallization. Through melting the PEO lamellae in core, it can be found that the ion conduction as well as tan δ were enhanced. Based on these results, it is confirmed that the ion transport stemmed from IL was suppressed by the PEO lamellae. As the content of IL reached up to 20 wt%, tan δ of the composites with PEO lamellae was reduced to half of P/E/IL spinning fibers. [ABSTRACT FROM AUTHOR]

Electrocrystallization is a ubiquitous tool for the assembly of ions formed in situ from electroactive precursors into ordered crystalline macroscopic assemblies. Using tetrachalcogeno-fulvalene derivatives, many conducting and superconducting materials have been developed over the past fifty years, generally referred to as organic molecular conductors. The introduction of chirality in the structure of such molecular materials is encouraged by the possible observation of exotic physical effects, such as electrical magneto-chiral anisotropy (eMChA). Chirality is more commonly caused by the organic electron donor rather than the inorganic counter-anion. Herein, the synthesis of organic electrolytes based on a [4]helicene scaffold is described. Tetrabutylammonium salts of [4]helicene carboxylate and sulfonate have been synthesized and characterized. Electrocrystallization with three organic donors, namely tetramethyl-TTF (TMTTF), bis(ethylenedithio)-TTF (BEDT-TTF) and tetramethyl-tetraselenafulvalene (TMTSF), provided crystals whose single-crystal X-ray analysis is reported. While a covalent adduct of TMTTF has been observed with the carboxylate salt as the electrolyte, the structures display either discrete organic donor stacks of TMTTF and TMTSF or chains of laterally connected dimers of BEDT-TTF when sulfonate salts are used. [ABSTRACT FROM AUTHOR]

The kinetics and mechanism of the initial stages of electrocrystallization of nickel, iron and nickel-iron alloy were characterized for the process of electrolytic deposition from a solution based on deep eutectic solvent ethaline (liquid mixture containing choline chloride and ethylene glycol at a molar ratio of 1:2, respectively). The theoretical model developed by Scharifker and Hills was used to interpret the obtained experimental data. It was shown that the electrodeposition of nickel and iron obeys the patterns of three-dimensional instantaneous and progressive nucleation, respectively. It was concluded that the formation of iron nuclei occurs at a significantly lower rate than in the case of nickel. The kinetics of the initial stages of Ni–Fe alloy deposition obeys the mechanism of instantaneous nucleation. Thus, in the case of electrolytic deposition from ethaline-based solutions on a glassy carbon electrode, nickel imposes on iron not only its own region of electrode potentials where alloy deposition occurs, but also the type of mechanism of nucleation in the course of codeposition. [ABSTRACT FROM AUTHOR]

Declining earth resources, rising ore cost and increasing pollution are calling for recycling of wastewater in the context of the circular economy. In particular, urine is a potential source of phosphorus (P) and potassium (K), yet currently available methods for P and K recovery are limited in efficiency. Here, we designed an electrochemical crystallization system using sacrificial magnesium anodes to recover P and K in the form of K-struvite (MgKPO4·6H2O) from simulated urine at low (P/K = 0.25) and high (P/K = 0.6) phosphate levels, respectively. Results show optimal recoveries of 88.5% for P and 35.4% for K in the form of rod-shaped K-struvite at 3.5 mA/cm2, though higher current density reduced recovery due to side reactions and pH increase. Seeding prefabricated struvite crystals at 1.6 g/L into urine enhanced the recovery of K by 14.7% and of P by 23.7% compared to the control group. Overall, our findings show that electrochemical crystallization is promising to recover K-struvite fertilizers. [ABSTRACT FROM AUTHOR]

The effect of surfactants - calcium phenolate (phenolates of tertiary aminophenols), which has a significant size (1286 g/mol) and high activity (adsorbability) in electrolytes and has a positive effect on the scattering ability of the cadmium electrolyte, as well as on the quality of cadmium coatings was studied in this work. In the work, the usual parameters of the cadmium electrodeposition process, such as electrolyte composition, current density, temperature, and deposition time were used. The quality of the obtained cadmium coatings by using a new surfactant in the process of electrocrystallization of cadmium was determined on a JSM-6490LV scanning electron microscope with INSAEnergu energy dispersive microanalysis and HKL-Basic structural analysis systems with a useful magnification of 300.000. [ABSTRACT FROM AUTHOR]

The paper considers the problems of obtaining thin films of sodium-tungsten bronzes of a cubic structure by the method of electrocrystallization. The main parameters of the obtained films are presented. The reflection spectra of the films were recorded for uncolored and colored films. Investigation of the near-surface layer of sodium-tungsten bronze single crystals by protonography and nuclear reactions showed their high structural perfection. The anodic and cathodic polarizations of single crystals lead to a change in the structure of their surface layer. Depletion in sodium of the near-surface layer is present at both cathodic and anodic polarization, and the depletion depth increases with increasing polarization time of the voltage value. Thin films of sodium-tungsten bronzes have been investigated by electron diffraction, and the amorphous structure of freshly deposited films has been established for all substrate temperatures. Annealing with an electron beam leads to crystallization of the films.

Bis(phthalocyaninato)lanthanoid(III) (LnPc2) complexes have attracted significant attention for their exceptional optical, electronic and magnetic properties. Crystallization of these compounds usually requires cumbersome methods such as sublimation and electrocrystallization, which is a significant limitation to both structural determinations and the preparation of high purity materials at scale. We report here the selective crystallization of four polymorphs of LnPc2 obtained exclusively by the slow evaporation of saturated solutions. The obtained phase depends on the initial oxidation state of the LnPc2 molecule and the choice of solvent. Single-crystal X-ray diffraction studies were used to determine 14 new structures including Ln = La, Pr, Nd, Sm, Gd, Tb, Dy, Er and Yb, as well as correct previous mis-identifications from the literature. We provide a detailed comparison of molecular structure and crystal packing in all LnPc2 polymorphs. The primary feature in all phases is columnar stacking based on parallel π–π interactions, with a variety of slip angles within those stacks as well as secondary interactions between them. Chemical redox and acid–base titrations, performed on re-dissolved crystals demonstrate that LnPc2+ and LnPc2− are easily obtained through weak oxidizing and reducing agents, respectively. Additionally, we show that the protonated form of the NdPc2− complex has a nearly identical UV-vis spectrum to that of neutral NdPc2, explaining some of the confusion over chemical composition in previously published literature. [ABSTRACT FROM AUTHOR]

Nanoparticles of the Per2[Au(mnt)2] (Per $=$ perylene; mnt2- $=$ maleonitrile dithiolate) compound have been obtained by the electrochemical oxidation of perylene in the presence of [(n-C4H9)4N][Au(mnt)2] and, either an amphiphilic molecule (OATM), or a zwitterionic ionic liquid (BIBS), acting as growth controlling agents. When the reaction is carried out with OATM, nanocrystals exhibiting sizes in the 35–100 nm range are grown whereas roughly spherical nanoparticles are observed if BIBS is used (10–40 nm in diameter). Infrared and Raman spectra confirm the presence of both perylene donor and maleonitrile dithiolate ligands within the nanopowders. Electrical conductivity measurements at room temperature lead to about $0.025~\mathrm{S}{\cdot }\mathrm{cm}^{{-1}}$, a typical value for nanopowders of bis(dithiolene)-based conducting compounds. Finally, current–voltage characteristics for the spherical nanoparticles are fitted with a Shockley diode model. A saturation current of 19.3 pA and a threshold voltage of 0.149 V are extracted from this model.

In metal oxide nanofiber fabrication using the electrospinning method, heat treatment is performed at temperatures of 500°C or higher for crystallization and polymer desorption. Therefore, it is difficult to fabricate low‐temperature phase metal oxides that crystallize at low temperatures. TiO2, a representative metal oxide often used as photocatalysts, is known to have higher photocatalytic activity in the low‐temperature phase (anatase structure) than in the high‐temperature phase (rutile structure). Studies on the fabrication of TiO2 anatase nanofibers using conventional electrospinning have reported disadvantages such as the partial expression of rutile structures and low crystallinity. This study developed an anatase TiO2 nanofiber as a high‐efficiency catalyst based on the electrospinning method and a residual organic matter cleaning method that employs ultra‐violet (UV) light. We fabricated nanofibers using the electrospinning method and implemented TiO2 nanofibers with the anatase structure through heat treatment at 260°C. Residual organics remaining after heat treatment of the fabricated crystalized TiO2 nanofibers were removed by exposing them to UV light, thereby improving photocatalytic efficiency. The photocatalytic efficiency of the fabricated TiO2 nanofibers was confirmed through a methylene blue (MB) decomposition experiment under visible light irradiation. The photocatalytic efficiency (time taken for the concentration of the MB solution to reach 50%) of the UV‐treated TiO2 nanofibers was approximately six times higher than of P25 and the heat‐treated nanofibers. [ABSTRACT FROM AUTHOR]

Tetrathiafulvalene (TTF) is a redox‐active compound, which reversibly undergoes two one‐electron oxidations to give stable species. Several features of TTF, such as redox and optical properties as well as geometry and self‐associating nature, can be tuned by extension of the conjugated system with an aromatic linker such as an indenofluorene (IF) moiety. In this work we present the synthesis of a novel dimeric scaffold of IF‐extended TTF (IF‐TTF) in which the units are linked by a rigid 1,4‐bis(2‐ethynylphenyl)buta‐1,3‐diyne moiety. 1H‐NMR spectroscopic studies reveal that the scaffold is highly prone to form intramolecular IF‐TTF dimer complexes even in the neutral form, and stable radical cation species were formed in solution upon chemical oxidation with tris(4‐bromophenyl)ammoniumyl hexachloroantimonate ('magic blue'). Electrocrystallization of the rigid scaffold yielded a semi‐conducting material, which proved to be stable at ambient temperature and air. [ABSTRACT FROM AUTHOR]