Chemical Charge Research Articles

Targeted delivery of a selenium-sulfa compound via cationic starch microparticles: Modulation of oxidative stress and pain pathways in fibromyalgia-like symptoms in mice

Cationic starch microparticles (CStMPs) loaded with 4-amino-3 -(phenylselenyl)benzenesulfonamide (4-APSB) were prepared and investigated in a model of fibromyalgia (FM) induced by intermittent cold stress (ICS) in male and female Swiss mice. The CStMPs/4-APSB were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, zeta potential, and particle size measurements, providing information about their chemical composition, surface charge, morphology/microstructure, and size (1.50 ± 0.5 μm). Following ICS exposure, the animals were treated with free 4-APSB (1 mg/kg), CStMPs/4-APSB (containing 0.13 mg of 4-APSB per mg of microparticles), or CStMPs, from days 5 to 10. The results revealed the successful incorporation of 4-APBS in the CStMPs. Free 4-APSB and CStMPs/4-APSB reversed nociceptive- and depressive-related behaviors in male and female mice exposed to ICS, attenuating the hallmark symptoms of FM. Those treatments (free 4-APSB and CStMPs/4-APSB) normalized the monoamine oxidase (MAO)-A activity in the cerebral cortex and the oxidative damage, providing the correct functioning of the enzyme Ca2+ -ATPase in the cerebral cortex and hippocampus of mice exposed to ICS. The CStMPs/4-APSB modulated the oxidative stress markers, specifically in the spinal cord of mice - an anatomical region intricately linked to pain pathways.

Unveiling the potential of Au cocatalysts to induce SPR charges on CuO/CdS system for sunlight driven hydrogen production†

Atmospheric pollution and increasing costs of the fossil fuels have compelled the researchers to explore the alternative sources. The objective of current project is to discover the stable catalysts that can drive water splitting reaction with sunlight. To the purpose, visible light active catalysts i.e. CdS, CuO/CdS, and Au@CuO/CdS have been synthesized and evaluated for hydrogen generation activities. Gold cocatalysts have been employed to enhance the surface stability and catalytic efficiencies. Whereas, CuO/CdS heterojunction have been synthesized to improve charge separation ability. The optical characteristics, structural properties, and morphology of catalysts have been evaluated by UV‒Vis/DRS, XRD, Raman, BET, SEM, AFM, PL and FTIR techniques. Chemical compositions, photocurrent or charge transfer have been verified with XPS, EDX and EIS results. Catalytic reactions were performed in photoreactor (150mL/Pyrex), whereas hydrogen production activities were predicted via online GC-TCD (Shimadzu-2010/Japan). Results depict that catalyst with 0.8% of Au on CuO/CdS exhibit relatively higher activity (i.e. 32.13 mmolg‒1h‒1) than the other catalysts of the series. Higher activities were attributed to the presence of Au cocatalysts. It has been predicted that coexistence of gold develops Schottky junctions that progressively rectify the surface charges (i.e. movement of electrons). Additionally, gold induces the SPR charges and enhances activity of electrons. Schottky junctions formed by Au cocatalysts on CuO/CdS system restrict the charge recombination i.e. back reactions. In this study, various factors like temperature, pH, light intensity and dose of catalysts have been assessed and discussed. On the basis of activities, it has been concluded that work reported herein hold promise to replace the conventional catalysts used for hydrogen energy technologies.

Synthesis, quantum chemical insights, vibrational spectral elucidation, insecticide likeness and docking analysis of the insecticide active novel molecule 2-(4-nitrophenyl)-(3,5-difluoro-pyridine-6-yl)-1,3,4-oxadiazole

Oxadiazole derivatives containing pyridine moiety were biologically active molecules that have been widely applied in recent years in research on pesticides, particularly insecticides. In this work, a newly synthesized 2-(4-nitrophenyl)-(3,5-difluoro-pyridine-6-yl)-1,3,4-oxadiazole compound was characterized using spectroscopic techniques. The quantum chemical computations based on density functional theory were employed to investigate the molecular configuration of title compound. The modes of vibrations of the compound were identified through potential energy distribution, and the results were consistent with the experimental infrared and Raman data. Natural bond orbital assessment evaluated the significant donor-acceptor interactions within the molecule. The frontier molecular orbital analysis was performed to obtain global reactivity parameters. The molecular electrostatic potential was used to visualize the chemical reactivity and charge distribution of the molecule. From the nuclear magnetic resonance spectra, the carbon atoms bonded with nitrogen and oxygen atoms show the up-shielded peaks. The chemical implication of molecule was explained using electron localization function and localized orbital locator analysis. Moreover, the molecular docking studies performed for the newly synthesized compound revealed an efficient interaction with the acetylcholine receptor and exhibited better binding affinity than commercialized insecticides. Whilst, the physicochemical properties were assessed using the insectiPAD webtool to comprehend the insecticidal properties of title compound. Finally, the quantitative structure activity relationship study of 2-(4-nitrophenyl)-(3,5-difluoro-pyridine-6-yl)-1,3,4-oxadiazole showed higher activity (pLC50 = −1.43) against Mythimna separata, as compared to commercial insecticide avermectin (pLC50 = −1.47). These results provided that title compound could be used as a template for future insecticide investigations.

Information theoretic measures for Lifshitz system

In this work, we have studied various mixed state information theoretic quantities for an excited state of Lifshitz spacetime in 3 + 1-dimensions. This geometry is the gravity dual to a class of 2 + 1-dimensional quantum field theories having Lifshitz symmetry. We have holographically calculated mutual information, entanglement wedge cross section, entanglement negativity and mutual complexity for strip like subsystems at the boundary. For this we have used the results of holographic entanglement entropy and complexity present in the literature. We first calculate all of these mentioned quantities for the pure state of Lifshitz spacetime. Then we have moved on to calculate all these quantities for excited state of the Lifshitz spacetime. The gravity dual of excited state of Lifshitz systems in field theory can be obtained by applying constant perturbations along the boundary direction. Further, we would like to mention that for the simplicity of calculation we are only considering results up to the first order in perturbation. The change in the obtained holographic information theoretic quantities are then related to entanglement entropy, entanglement pressure, entanglement chemical potential and charge using the stress tensor complex. These relations are analogous to the first law of entanglement thermodynamics given earlier in the literature. All the calculations are carried out for both values of dynamical scaling exponent (z) present in the Lifshitz field theory.

DFT study of difluoro & trifluoro bi-cyclohexane based dimer for application in electronic and optical devices

This investigation outlines a comprehensive analysis of the electronic and optical characteristics of difluoro and trifluoro bi-cyclohexane-based dimers in different conformations, specifically focusing on two distinct molecules: 4-(2,2,-difluorocyclopropyl)-4′-propyl-1,1′-bi(cyclohexane) and 4-propyl-4′-(1,2,2,-trifluorocyclopropyl)-1,1′-bi(cyclohexane). Utilizing Density Functional Theory (DFT) with advanced functionals M06-2X and B3LYP paired with a 6-311G(d,p) basis set, this study probes the interaction energy, orbital behaviors, and non-linear optical (NLO) properties across two primary molecular orientations such that in-plane and stacked.Our findings reveal that both configurations exhibit remarkable non-linear optical properties as evidenced by significant change in values of polarizability and hyperpolarizability, with the latter suggesting enhanced suitability for NLO applications. This study also ventures into frontier molecular orbital analysis, offering predictive insights into the chemical reactivity and charge transfer phenomena intrinsic to these molecular systems.

Remaining useful life prediction of lithium-ion batteries based on autoregression with exogenous variables model

The gradual decrease capacity serves as a pivotal health indicator, reflecting the condition of lithium-ion batteries. Accurate forecasting of capacity can ascertain the remaining lifespan of these batteries at any given cycle, which is crucial for managing batteries in electric vehicles. This paper proposes an Autoregression with Exogenous Variables (AREV) model, which continually updates itself through a sliding window, offering predictions of battery state of health and remaining useful life, which extends battery prognostics at a fixed operating condition to different operating conditions. In addition, unlike most models that require multiple battery data of the same type for training, the proposed model only requires the use of fragmented data of the target battery with length around 30-50 cycles for capacity prediction and determines battery life based on battery failure thresholds. The above two points enable this model to be updated online without the need for any offline training. Finally, four different types of battery dataset , with different chemical substances and different charge and discharge conditions (especially dataset that follows random walk discharging profile to stimulate the real power consumption process) , are applied to verify the effectiveness and robustness of proposed RUL prediction approach. It shows that the proposed model can accurately predicting future capacity values. Timely warning signals can be issued before the end of life of battery, thereby ensuring the safe driving of electric vehicles and timely battery replacement.

Beyond monopole electrostatics in regulating conformations of intrinsically disordered proteins.

Conformations and dynamics of an intrinsically disordered protein (IDP) depend on its composition of charged and uncharged amino acids, and their specific placement in the protein sequence. In general, the charge (positive or negative) on an amino acid residue in the protein is not a fixed quantity. Each of the ionizable groups can exist in an equilibrated distribution of fully ionized state (monopole) and an ion-pair (dipole) state formed between the ionizing group and its counterion from the background electrolyte solution. The dipole formation (counterion condensation) depends on the protein conformation, which in turn depends on the distribution of charges and dipoles on the molecule. Consequently, effective charges of ionizable groups in the IDP backbone may differ from their chemical charges in isolation-a phenomenon termed charge-regulation. Accounting for the inevitable dipolar interactions, that have so far been ignored, and using a self-consistent procedure, we present a theory of charge-regulation as a function of sequence, temperature, and ionic strength. The theory quantitatively agrees with both charge reduction and salt-dependent conformation data of Prothymosin-alpha and makes several testable predictions. We predict charged groups are less ionized in sequences where opposite charges are well mixed compared to sequences where they are strongly segregated. Emergence of dipolar interactions from charge-regulation allows spontaneous coexistence of two phases having different conformations and charge states, sensitively depending on the charge patterning. These findings highlight sequence dependent charge-regulation and its potential exploitation by biological regulators such as phosphorylation and mutations in controlling protein conformation and function.

Hierarchical interconnected polyaniline nanocomposite with hydrothermally synthesized pyrite structure for improved electrochemical properties in a vanadium redox flow battery

In this study, FeS2 (FS) was synthesized via the hydrothermal technique. The various percentages of FS were subsequently incorporated into polyaniline (PANI) through an in-situ chemical process, aiming to improve the performance of the vanadium redox flow battery (VRFB). The synthesized nanocomposites (NPFS) were characterized using various techniques such as spectroscopy, microscopy, chemical, thermal study and electrochemical analysis (CV, EIS and Tafel) and charge discharge cycles study to understand their structure and performance. Morphological, chemical and structural analyses revealed the successful integration of FS into the PANI matrix, forming a hierarchical with highly porous nanocomposite structure. The results of the electrochemical analysis significantly improved the redox behavior and charge transfer kinetics compared to PANI. Based on the characterization and electrochemical characterizations, the best performing composition (NPFS15) sample (3 mg/cm2) was coated on 132 cm2 graphite felt (GF) and inserted in VRFB to examine the charge–discharge cycles. At a current density 70 mA/cm2, the selected nanocomposite with the specified loading on GF exhibited superior electrochemical performance due to the sufficient availability of active sites. Besides, the integration of NPFS nanocomposite materials in VRFB technology may pave the way for more efficient and sustainable energy storage solutions in the future.

Evaluating chemi-mechanical pulping processes of agricultural residues: High-yield pulps from wheat straw for fiber-based bioproducts

This work evaluates the feasibility of APMP (alkaline peroxide mechanical pulping) and CTMP (chemi-thermomechanical pulping) of wheat straw as small-scale, low-capital expenditure pulping process to produce high-yield pulps for fiber-based bioproducts. APMP and CTMP wheat straw pulps were characterized in terms of pulping yield, freeness, ISO brightness, and fiber morphology. Additionally, both pulps were evaluated for tissue paper applications and benchmarked against BEK (bleached eucalyptus kraft) market pulp. APMP wheat straw pulps presented higher yield (75.2 – 79.8 %) compared to CTMP (69.1 – 80.6 %), depending on cooking chemicals and chemical charge during the chemical impregnation stage. The final brightness of APMP pulps varied from 36.4 % to 37.8 % ISO when sodium hydroxide and hydrogen peroxide were used as pulping agents without additional chemical additives. However, the brightness of APMP pulps can be increased up to 49.7 % ISO by using additional chemical additives such as EDTA (chelating agent), sodium silicate (peroxide stabilizer), or by employing a multi-stage chemical impregnation strategy. Both pulps produced fibers with similar morphological properties. A comparison of tissue-making properties showed that APMP pulps produced bulkier handsheets with higher water absorption capacity and better softness than CTMP pulps. However, CTMP pulps exhibited a higher tensile index than APMP pulps for a given pulp freeness. The results indicate that non-wood fibers, such as those derived from wheat straw, could be a promising alternative for use in fiber-based bioproducts such as hygiene tissue.

Chemical potential and charge in quantum black holes

We study systems in 2 + 1 dimensions consisting of defects that source an electric charge, or a magnetic flux, of a U(1) field, and we use holography to compute their effects on quantum conformal fields. We can also hide the defects inside the horizon of a black hole, where they continue to affect the quantum fields outside. By extending the solutions to braneworld holography, we find the non-linear backreaction of the quantum fields on the defect and black hole backgrounds. This gives quantum charged point particles and black holes. The charged quantum black holes markedly differ from classically charged BTZ black holes, since the quantum-induced electromagnetic field in 2 + 1 dimensions has a better asymptotic behavior than its classical counterpart. The construction also gives a new class of (near-)extremal charged quantum black holes with AdS2 throats.

Synthese und Charakterisierung eines Kupfer‐Distickstoff‐Komplexes unter Verwendung eines schwach koordinierenden Anions

AbstractWir stellen die Synthese und vollständige Charakterisierung des Kupfer‐Distickstoff‐Komplexes [(η1‐N2)Cu{Al(ORF)4}] 2 (RF=C(CF3)3) vor, welcher durch eine Kaskaden‐Metathese‐Reaktion zwischen Ag[Al(ORF)4] und einem CuI‐Überschuss in iso‐Perfluorhexan (i‐pfh) unter N2‐Atmosphäre hergestellt wurde. Die Titelverbindung 2 weist eine außerordentlich hohe N2‐Streckschwingungsfrequenz von 2313/2314 cm−1 (IR/Raman) auf und wurde durch Einkristall‐ und Pulver‐Röntgendiffraktometrie charakterisiert. Quantenchemische Ladungsverschiebungsanalysen basierend auf natürlichen Orbitalen der chemischen Valenz (CD‐NOCV) legen nahe, dass die Kupfer‐Distickstoff‐Interaktion durch eine schwache π‐Rückbindung charakterisiert wird, welche jedoch im Vergleich zu allen literaturbekannten Übergangsmetall‐Distickstoff‐Komplexen stark abgeschwächt ist.

Synthesis and Characterization of a Copper Dinitrogen Complex Supported by a Weakly Coordinating Anion.

We report the synthesis and full characterization of the copper dinitrogen complex [(η1-N2)Cu{Al(ORF)4}] 2 (RF=C(CF3)3) prepared by a cascade metathesis reaction of Ag[Al(ORF)4] with CuI-excess in iso-perfluorohexane (i-pfh) under N2 atmosphere. Title compound 2 features an extraordinarily high N2 stretching frequency at 2313/2314 cm-1 (IR/Raman) and was characterized by single-crystal and powder X-ray diffractometry. Quantum chemical charge displacement analysis based on natural orbitals of chemical valence (CD-NOCV) indicates that the copper-dinitrogen interaction is still governed by weak π-backdonation, but is significantly reduced compared to all literature-known transition metal dinitrogen complexes.

(Industrial Electrochemistry and Electrochemical Engineering Division H. H. Dow Memorial Student Achievement Award) Tailoring Electrode-Electrolyte Interfaces through Non-Covalent Interactions for Electrochemical Energy Storage and Conversion

Li-ion batteries and fuel cells play essential roles in electrifying transportation. Central to the electrochemical systems is the electrode-electrolyte interface, where (electro)chemical surface reactions or intercalation occur, and its thermodynamic and kinetic properties determine the energy density, power density, and lifetime of the electrochemical devices. However, the molecular structures at the electrical double layer and reaction mechanisms remain poorly understood, hindering the rational material design for more efficient electrochemical devices. This talk focuses on the mechanisms of (electro)chemical reactions and charges transfer kinetics at the electrode-electrolyte interface, providing design principles based on non-covalent interactions in electrolytes.First, an in situ Fourier-transform infrared spectroscopy (FTIR) method was developed for Li-ion batteries, which revealed unique evidence for dehydrogenation of carbonate electrolytes on Ni-rich lithium nickel, manganese and cobalt oxides (NMC), accounting for interface impedance build-up and battery capacity fading. Based on the proposed mechanism, strategies on suppressing electrode and electrolyte reactivity were demonstrated to improve battery cycling. Next, the kinetic mechanism for ion intercalation at the electrode-electrolyte interface will be discussed. Li-ion concentration-dependent intercalation kinetics was demonstrated from charge-adjusted electrochemical experiments and fit into a coupled ion-electron transfer mechanism, which governed the current-dependent maximum capacity and power density of intercalation batteries. Finally, for electrocatalytic reactions central to fuel cell technologies, we demonstrated tuning interfacial hydrogen bonding through protic ionic liquids with different acid dissociation constants and organic solvents with different donor numbers to tailor oxygen-reduction reaction (ORR) and hydrogen evolution reaction (HER). Strengthening hydrogen bonding between ORR products and ionic liquids, or between interfacial water molecules facilitated proton-coupled electron transfer kinetics, revealed by in situ surface-enhanced infrared absorption spectroscopy and density functional theory (DFT) calculations. The study can pave the way for the electrolyte and electrode design of electrochemical storage devices with improved energy and power density and cycle life.

(Invited) Probing Charge Carrier-Induced Changes in the Complex Dielectric Function in Carbon Nanotube Dispersions

The injection of charge carriers into pi-conjugated semiconductors, whether by electrochemical injection or chemical charge transfer, is a powerful approach to tune their electrical conductivity. Recently, the concept of dielectric catastrophe, where the charge carrier density is sufficiently large to significantly alter the intrinsic dielectric properties, has been demonstrated at high doping levels in organic semiconductor thin films. The observed increase in the dielectric constant leads to reduced coulombic interactions between charge carriers and the associated counterions, promoting enhanced free carrier generation and transport.Here, we employ a combination of steady state optical spectroscopy, quantitative 19F NMR studies, and microwave dielectric loss spectroscopy to probe charge carrier density and transport in doped single-walled carbon nanotube dispersions. We demonstrate that a similar dielectric catastrophe phenomenon can be observed even in isolated single-walled carbon nanotubes dispersed in a low dielectric constant solvent AND, perhaps more surprisingly, at carrier densities less than one carrier per nanotube. The precise details of the observed changes in complex dielectric function are dependent on the chemical structure of the charge-transfer dopant, with a near-instantaneous increase in the dielectric constant and electrical conductivity observed for low carrier densities using bulky benzyloxy-substituted icosahedral dodecaborane cluster dopants, DDBs. We attribute the observations to weak coulombic interactions between the injected charge carrier and the dopant counterion, along with the large polarizability afforded by the unique physicochemical properties of single-walled carbon nanotubes. If time permits, we will show results from recent studies where we extend this approach to the doping of other nanocarbons.

The Effects of Autohydrolysis Pretreatment on the Properties of OPT Pulps for the Production of Dissolving Pulp

This preliminary study investigated an environmentally friendly method for fabricating cellulose-rich dissolving pulp from Oil Palm (<i>Elaeis guineensis</i>) Trunk (VBOPT) fibre. This method encompassed an autohydrolysis pretreatment followed by soda pulping procedures. The impact of autohydrolysis pretreatment on the separation of lignocellulosic components was scrutinised to facilitate the production of chemical cellulose. Autohydrolysis was performed on VBOPT fibre for 60 min at temperatures ranging from 140°C to 160°C, maintaining a solid-to-liquid ratio of 1:8. The yield of the prehydrolysed OPT varied between 73.5% and 91.5%. The chemical composition of the prehydrolysed VBOPT fibre comprised 70.6–80.0% holocellulose, 63.7–87.1% α-cellulose, 7.4–10.9% ß-cellulose, 5.5–25.4% γ-cellulose, and 21.5–26.6% lignin. The prehydrolysed OPT was subsequently subjected to alkaline pulping under fixed conditions: a temperature of 160°C, a treatment time of 60 min, a chemical charge of 25%, and a solid-to-liquid ratio of 1:6. The resultant pulp exhibited properties such as a screening yield of 41.5–46.4%, a kappa number of 4.5–9.6, and α, β, and γ cellulose content of 89.4– 98.1%, 1.5–5.3%, and 0.4–6.9%, respectively. Based on the chemical composition of the OPT biomass before and after pretreatment, as well as post-alkaline cooking, the autohydrolysis pretreatment was determined to significantly influence the resultant pulp. A more comprehensive understanding of the interdependence of autohydrolysis and pulping processes can be achieved by executing an optimisation study focusing on key parameters of autohydrolysis and pulping, including temperature, treatment duration, and chemical charge.

Ferrimagnetic pseudocapacitive MnFe2O4 electrodes and supercapacitor devices

This investigation is motivated by the surge of interest in materials, combining high spontaneous magnetization and pseudocapacitance at room temperature. Ferrimagnetic MnFe2O4 offers benefits of high magnetization. However, the non-pseudocapacitive behavior, low capacitance and high resistance of MnFe2O4 are limiting factors for its applications in magnetic pseudocapacitive devices. This investigation demonstrates that nearly ideal pseudocapacitive behavior can be achieved for MnFe2O4 electrodes in Na2SO4 electrolyte. High pseudocapacitance is observed in positive and negative potential ranges and two different charging mechanisms are proposed. High capacitance is achieved at a low impedance. The ability to achieve comparable and high areal capacitances in the positive and negative potential ranges facilitates the fabrication of a symmetric pseudocapacitive device, containing ferrimagnetic MnFe2O4 as cathode and anode material for operation in enlarged voltage window of 1.6 V. The symmetric device shows capacitance of 0.92 F cm−2 at a current density of 3 mA cm−2. The individual electrodes and device show good cycling stability. The approach is based on the use of murexide and gallocyanine as redox-active dispersants and charge transfer mediators. The analysis of testing results provides an insight into the influence of chemical structure, charge and redox properties of the dispersants on the capacitive behavior. The ability to fabricate a pseudocapacitive device, containing two ferrimagnetic electrodes is promising for energy storage, water purification and novel applications based on magnetocapacitive effects.

A Wearable Self-Charging Electroceutical Device for Bacteria-Infected Wound Healing.

The prolonged wound-healing process caused by pathogen infection remains a major public health challenge. The developed electrical antibiotic administration typically requires metal electrodes wired to a continuous power supply, restricting their use beyond clinical environments. To obviate the necessity for antibiotics and an external power source, we have developed a wearable synergistic electroceutical device composed of an air self-charging Zn battery. This battery integrates sustained tissue regeneration and antibacterial modalities while maintaining more than half of the initial capacity after ten cycles of chemical charging. In vitro bacterial/cell coculture with the self-charging battery demonstrates inhibited bacterial activity and enhanced cell function by simulating the endogenous electric field and dynamically engineering the microenvironment with released chemicals. This electroceutical device provides accelerated healing of a bacteria-infected wound by stimulating angiogenesis and modulating inflammation, while effectively inhibiting bacterial growth at the wound site. Considering the simple structure and easy operation for long-term treatment, this self-charging electroceutical device offers great potential for personalized wound care.

Comparative study on graphene oxide and sulfonated graphene oxide reinforced polyethersulfone-based cation-exchange membrane

In this research, polyethersulfone/sulfonated graphene oxide (PES/SGO) heterogeneous cation exchange membranes were fabricated by the mold casting method. The sulfonation of GO was carried out using the diazonium salt of sulfanilic acid. The properties of the synthesized GO and SGO were compared in terms of chemical structure, morphology, surface charge, crystallinity, and thermal stability. The variations in surface morphology and roughness, hydrophilicity, dimensional stability, and ionic conductivity of the PES-based membranes as a function of GO and SGO content were investigated. Results revealed that SGO enjoyed a higher level of oxygenated groups contributing to its higher surface charge. SGO also tolerated a higher temperature before being fully decomposed due to the presence of the sulfur-containing groups. A finer nanostructured morphology was observed in the SGO-containing membranes, resulting in a considerably lower surface roughness of these membranes than the corresponding GO-based membranes. The membrane comprising 10 wt% SGO showed the lowest surface roughness of 88 nm, and the highest water uptake of 16.66 %, ion-exchange capacity of 1.12 meq g-1, and the lowest charge transfer resistance of 3.6 Ω and area resistance of 0.9 Ωcm2. This was accompanied with a considerable increment in the permselectivity and cation (Na+) transport number of this membrane to 95.9 % and 97.5 %, respectively, due to the higher surface adhesion energy of 94.57 J m-2 and higher Na+ flux of 4.43×10-7 mol m-2 s-1, which were significantly higher than that obtained for the corresponding PES-based membrane containing 10 wt% GO. Furthermore, a lower weight loss and resistance change were observed for PES/SGO after being exposed to the Fenton reagent for 9 h, indicating the impact of the sulfonated groups on the oxidative stability enhancement of the membrane.

Chiral-structured heterointerfaces enable durable perovskite solar cells.

Mechanical failure and chemical degradation of device heterointerfaces can strongly influence the long-term stability of perovskite solar cells (PSCs) under thermal cycling and damp heat conditions. We report chirality-mediated interfaces based on R-/S-methylbenzyl-ammonium between the perovskite absorber and electron-transport layer to create an elastic yet strong heterointerface with increased mechanical reliability. This interface harnesses enantiomer-controlled entropy to enhance tolerance to thermal cycling-induced fatigue and material degradation, and a heterochiral arrangement of organic cations leads to closer packing of benzene rings, which enhances chemical stability and charge transfer. The encapsulated PSCs showed retentions of 92% of power-conversion efficiency under a thermal cycling test (-40°C to 85°C; 200 cycles over 1200 hours) and 92% under a damp heat test (85% relative humidity; 85°C; 600 hours).

Colossal Ferroelectric Photovoltaic Effect in Inequivalent Double-Perovskite Bi2FeMnO6 Thin Films.

Double perovskite films have been extensively studied for ferroelectric order, ferromagnetic order, and photovoltaic effects. The customized ion combinations and ordered ionic arrangements provide unique opportunities for bandgap engineering. Here, a synergistic strategy to induce chemical strain and charge compensation through inequivalent element substitution is proposed. A-site substitution of the barium ion is used to modify the chemical valence and defect density of the two B-site elements in Bi2FeMnO6 double perovskite epitaxial thin films. We dramatically increased the ferroelectric photovoltaic effect to ∼135.67 μA/cm2 from 30.62 μA/cm2, which is the highest in ferroelectric thin films with a thickness of less than 100 nm under white-light LED irradiation. More importantly, the ferroelectric polarization can effectively improve the photovoltaic efficiency of more than 5 times. High-resolution HAADF-STEM, synchrotron-based X-ray diffraction and absorption spectroscopy, and DFT calculations collectively demonstrate that inequivalent ion plays a dual role of chemical strain (+1.92 and -1.04 GPa) and charge balance, thereby introducing lattice distortion effects. The reduction of the oxygen vacancy density and the competing Jahn-Teller distortion of the oxygen octahedron are the main phenomena of the change in electron-orbital hybridization, which also leads to enhanced ferroelectric polarization values and optical absorption. The inequivalent strategy can be extended to other double perovskite systems and applied to other functional materials, such as photocatalysis for efficient defect control.