Simple Route Research Articles

Entropy-Stabilized Multication Fluorides as a Conversion-Type Cathode for Li-Ion Batteries-Impact of Element Selection.

Metal fluorides (e.g., FeF2 and FeF3) have received attention as conversion-type cathode materials for Li-ion batteries due to their higher theoretical capacity compared to that of common intercalation materials. However, their practical use has been hindered by low round-trip efficiency, voltage hysteresis, and capacity fading. Cation substitution has been proposed to address these challenges, and recent advancements in battery performance involve the introduction of entropy stabilization in an attempt to facilitate reversible conversion reactions by increasing configurational entropy. Building on this concept, high entropy fluorides with five cations were synthesized by using a simple mechanochemical route. In order to examine the impact of element selection, Co0.2Cu0.2Ni0.2Zn0.2Fe0.2F2 (HEF-Fe) was compared with Co0.2Cu0.2Ni0.2Zn0.2Mg0.2F2 (HEF-Mg), replacing electrochemically inactive Mg with Fe as an active participant in the conversion reaction. Combining electrochemical measurements with first-principles calculations, high-resolution electron microscopy, and synchrotron X-ray analysis, HEFs' battery performances and conversion reaction mechanisms were investigated in detail. The results highlighted that replacement of Mg with Fe was beneficial, with enhanced capacity, rate capability, and surface stability. In addition, it was found that HEF-Fe showed similar cycle stability without an electrochemically inactive element. These findings provide valuable insights for the design of high entropy multielement fluorides for improved Li-ion battery performance.

Scattered-fields-induced tunable narrow resonance in low-index dielectric meta-lattices for transflective display

The development of a transflective display is important for reducing the energy consumption of an outdoor display-device. Currently, it is desirable to have a transflector which can be switched between its reflective and transparent states. The present work provides a novel yet simple route for the development of such a transflector based on one-dimensional (1D) meta-lattice systems. The system studied is shown capable of exciting tunable narrow resonance in the reflectance spectra through the generation of the scattered-field-induced polarizing-field in the system. Surprisingly, while most work on dielectric metasurface relies on high-index material, here it is found that the phenomenon can be achieved with common low-index material. Hence, it is a promising alternative for the development of future display technology with more economical operational cost.

Boosting the bifunctional catalytic activity of Co3O4 on silver and nickel substrates for the alkaline oxygen evolution and reduction reactions

Developing an efficient bifunctional catalyst for oxygen reduction (ORR) and evolution reactions (OER) is a crucial step for the wide commercialization of alkaline water electrolyzers. However, a proper assessment and comparison of various catalysts is still challenging due to the different catalyst substrates and loadings. In this work, Co3O4 spinel nanoparticles (NPs) were investigated as a bifunctional catalyst at different substrates of glassy carbon or Ag bulk substrate or Ni particles and with different loadings. For Co3O4 (800 µg cm-2)/Ag electrode, not only the overpotential for ORR was 50 mV lower than the bare Ag electrode, but also the OER overpotential was 40 mV lower than the sole Co3O4. Besides, less than 1% peroxide intermediate was detected during ORR using the rotating ring disc electrode (RRDE) method, suggesting a 4-electron O2 reduction. Tafel slopes of 70 and 60 mV dec‑1 at Co3O4/Ag were obtained for ORR and OER, respectively. The improved bifunctional activity could be attributed to a synergistic effect between Co3O4 and the Ag support. For the loading effect, it is revealed that the number of accessible sites of Ag surface decreases with increasing the Co3O4 loading, as evaluated from lead-underpotential deposition measurements. Interestingly, after running ORR/OER cycles, the surface area increased by 4–6 times. This surface roughening was also confirmed by SEM and EDX. The study was extended to Co3O4+Ni mixed catalyst to validate the effect of the support on this induced synergism. Hence, this work provides a simple route for designing potential effective catalytic interfaces and contributes to unravelling the influence of the substrate and loading on the catalyst activity for water electrolyzers.

Decoding electrochemical dynamics: Examining the potential of GO/Cu1-xSrxCr2O4 nanocomposite for high-performance supercapacitor energy storage

In this study, pure Cu1-xSrxCr2O4/GO nanoparticles were successfully synthesized via a simple precipitation route followed by calcination at 70 °C for 2 h, resulting in a high-performance supercapacitor nanoelectrode material. Characterization techniques confirmed the formation and properties of the synthesized materials. X-ray diffraction (XRD) analysis revealed the crystalline structure of the nanocomposite, with the d-spacing value of GO changing to 7.6 Å and the presence of peaks indicating the Cu1-xSrxCr2O4 phase. The average crystalline sizes were found to be 13.5 nm for GO, 16.15 nm for CuCr₂O₄, and 21.2 nm for the Cu1-xSrxCr2O4/GO nanocomposite. Scanning electron microscopy (SEM) demonstrated the highly porous nature of the samples, with average grain sizes of 30 nm, 25 nm, and 27.4 nm for GO, CuCr₂O₄, and Cu1-xSrxCr2O4/GO, respectively. Elemental analysis using energy-dispersive X-ray spectroscopy (EDS) confirmed the presence of copper, chromium, and oxygen, along with minor impurities. Raman spectroscopy indicated an increased defect density in the Cu1-xSrxCr2O4/GO nanocomposite, with an ID/IG ratio of 1.57 compared to 1.01 for GO. Photoluminescence (PL) analysis showed a bandgap of 3.65 eV for GO and 2.49 eV for the Cu1-xSrxCr2O4/GO nanocomposite. Electrochemical characterization included electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The EIS analysis showed that the Cu1-xSrxCr2O4 /GO nanocomposite had a lower charge transfer resistance (Rct) of 1.29 Ω compared to GO and CuCr2O4, indicating higher conductivity. The maximum specific capacitance of the Cu1-xSrxCr2O4 /GO nanocomposite was 1935.8 F/g at a scan rate of 3 mV/s in 1 M KOH electrolyte, significantly higher than that of GO alone (480.190 F/g). This study demonstrates the potential of Cu1-xSrxCr2O4/GO nanocomposites as efficient supercapacitor electrode materials, showcasing enhanced capacitance and conductivity due to the synergistic effects of the components.

Sensitive Electrochemical Sensing Properties for Cyanide Detection Using Polyaniline/Cu-Vanadate Nanobelt-modified Electrode

Background: Cyanide is a toxic anion and may be discarded into the water environment, which is a serious threat to human beings and the environment. Hence, it is essential to explore a facile, sensitive method for cyanide detection. Polyaniline/Cu vanadate nanobelts serve as electrode materials for sensitive cyanide determination. Methods: Polyaniline/Cu vanadate nanobelts were obtained by a simple route using polyaniline, Cu vanadate nanobelts. The polyaniline/Cu vanadate nanobelts were measured via electron microscopy, diffraction, infrared spectrum, and electrochemical methods. Results: Amorphous polyaniline nanoparticles with a particle size of about 100 nm were attached firmly to the surface of Cu vanadate nanobelts. Electrochemical sensing properties for cyanide detection were analyzed using a cyclic voltammetry technique using the nanobelts-modified electrode. The cyclic voltammograms (CV) peaks centered at +0.64 V and +0.54 V were observed using the polyaniline/Cu vanadate nanobelts in 0.1 M KCl solution with 2 mM cyanide. The proposed composite nanobelt-modified electrode possessed the detection range and detection limit of 0.001-2 mM and 0.22 μM, respectively. Conclusion: Polyaniline greatly enhances the electro-catalytic performance of the Cu vanadate nanobelt-modified electrode for cyanide detection.

Full-spectral response of mesoporous Z-scheme nanoheterojunction NaYF4:Yb,Tm@ZnO/BiOI photocatalysts for simultaneous contaminant and pathogen elimination in wastewater

The increasing contamination of water bodies demands effective and economical solutions for wastewater treatment. This study introduces a novel Z-scheme photocatalyst, NaYF4:Yb,Tm@ZnO/BiOI (UZB), synthesized via a simple chemical route. UZB exhibits exceptional photocatalytic degradation efficiencies of 95.1%, 88.7%, and 56.3% for methyl orange under full spectrum, visible, and near-infrared light, respectively. The integration of heterostructures within UZB promotes efficient charge carrier separation, significantly boosting its photocatalytic activity. When applied to actual wastewater, UZB markedly reduces chemical oxygen demand (COD) and total organic carbon (TOC) by 94.1% and 53.2%, respectively, and also effectively decreases turbidity and ammonia concentrations. Additionally, UZB shows strong antibacterial effects against S. aureus and E. coli, with inhibition rates of 93.9% and 92.0%, though some cytotoxicity is noted. These results underscore UZB's potential as a highly efficient photocatalyst for the simultaneous removal of organic pollutants and pathogens from wastewater, supporting its application in industrial water treatment systems.

A Highly Sensitive and Selective Iron Ion Fluorescent Probe for Water‐Soluble Pillar[5]Arene

AbstractA novel d‐gluconamide‐functionalized water‐soluble pillar[5]arene (GWP5) was synthesized through a simple synthetic route. GWP5 showed a remarkable aggregation‐induced emission (AIE) with increasing concentration. This feature served as the basis for the construction of an AIE‐based sensor for fluorescence detection of Fe3+ with high sensitivity and selectivity, with a linear relationship between luminescence quenching and Fe3+ concentration observed from 0 to 20 µM, and a limit of detection of 7.84 × 10−9 M. This fluorescent probe could be applied to the detection of Fe3+ ions in real environmental water samples and in serum samples.

Facile Synthesis of Colocasia esculenta Peels‐Derived Activated Carbon for High‐Performance Supercapacitor

ABSTRACTBiomass and biowaste resources can be used to create self‐doped carbon with a distinctive microstructure. Using an economical and environmentally friendly method to create heteroatom‐doped carbon electrode materials with excellent electrochemical performance has attracted much attention in the energy storage industry. A novel facile two‐step, low‐cost, and eco‐friendly synthesis method for Colocasia esculenta peels has been developed to manufacture activated carbon (CEPAC) and used as an electrode material for supercapacitor application. The CEPAC 1:1 displayed a high specific surface area of 910 m2/g with oxygen‐heteroatom polar sites in the carbon network. A specific capacitance of 525.3 F/g was recorded in the three‐electrode system using a 3 M KOH solution. The assembled symmetric cell delivered an impressive specific capacitance of 98.7 F/g at 1 A/g while maintaining 98.4% of the initially recorded capacitance after 10 000 charge–discharge cycles. These results present a promising low‐cost and simple processing route for synthesizing electrode materials with superior surface properties for high‐performance supercapacitors.

Indium‐Catalyzed Direct Amidation Reaction of Carboxylic Acids and In Silico Study for Screening the Activity of Potential Therapeutics of the Synthesized Products

AbstractAmide bonds are ubiquitous and valuable motifs in synthetic chemistry, found in a wide range of applications such as the backbone of proteins and pharmaceutical agents. Thus, environmentally friendly and selective methods for synthesizing amide bonds are important. Herein, we report a simple, efficient, and rapid route to access a range of functionalized amides from non‐activated carboxylic acids and amines using indium (III) trifluoromethanesulfonate as an efficient catalyst. A wide range of carboxylic acids – including aliphatic, aromatic, heterocyclic, and dicarbonyl acids – participate smoothly in these reactions, generating structurally diverse amides in moderate to good yields (up to 91 % in 24 examples). The reactions are conducted in dry tetrahydrofuran (THF) under reflux conditions. Furthermore, this amidation strategy provides a method for addressing challenging molecules, such as protected amino acids, to produce biocompatible products. These products can then be used as substrates for various organic transformations, including C−H functionalization reactions. We also demonstrate the synthetic utility of our protocol through the synthesis of essential substrates in organic and medicinal chemistry by reacting N‐protected carboxylic acids with 8‐aminoquinoline to produce a series of biologically valuable compounds. Five of these products, named 4 f, 4p, 9a, 9c, and 9d, have been biologically evaluated through an in‐silico study. The interaction of these compounds with receptor protein 8DQT was examined to assess their potential as drug candidates for hypertension treatment. Effective binding was detected between these compounds and the receptor. Data from molecular docking studies show that compounds 4d and 4 m are the most active, with binding scores of −8.8 and −8.6 kcal/mol, respectively. However, compound 4 m exhibited a stronger binding affinity than compound 4d over the course of dynamic simulation. Our ADMET study suggests that all five compounds are highly safe in the body. Based on the BOILED‐Egg model study, good absorption is suggested for all the molecules, and they can cross the blood‐brain barrier.

Fabrication of core–shell nickel ferrite@polypyrrole composite for broadband and efficient electromagnetic wave absorption

Herein, nickel ferrite@polypyrrole (NiFe2O4@PPy) composite was prepared by a simple two-step route of solvothermal synthesis and in-situ oxidation polymerization reaction. The results of micromorphology analysis showed that the obtained NiFe2O4@PPy composite had a unique core–shell structure, good magnetic performance and electrical conductivity. Furthermore, the as-prepared magnetic/conductive NiFe2O4@PPy composite exhibited notably enhanced electromagnetic wave (EMW) absorption performance than pure NiFe2O4 and PPy. When the filling ratio was 17.5 wt% and the matching thickness was 2.24 mm, the optimal minimum reflection loss (RLmin) of −56.25 dB and a broad effective absorption bandwidth (EAB) of 5.2 GHz were achieved for NiFe2O4@PPy composite. With slightly increasing the matching thickness to 2.6 mm, the maximum EAB of 7.12 GHz could be reached. Additionally, the probable EMW absorption mechanism was elucidated. Therefore, this work could provide a valuable reference for the preparation of magnetic ferrite/conductive polymer composites as broadband and high-efficiency EMW absorbers.

Cobalt-free spinel–layered structurally integrated Li0.8Mn0.64Ni0.183Fe0.091O2 cathodes for lithium-ion batteries

Cobalt-free, Li-rich layered-spinel structurally integrated positive electrode (cathode) materials for lithium-ion batteries (LIBs), with nominal composition 0.6(Li1.2Mn0.56Fe0.08Ni0.16O2) 0.4(LiFe0.2Mn1.4Ni0.4O4) which can otherwise be written as Li0.8Mn0.64Ni0.183Fe0.091O2 (FeSL) are synthesized via simple citric acid-assisted sol-gel route. Four different final annealing temperatures (550 °C, 650 °C, 750 °C, and 850 °C) were chosen to investigate their influence on electrochemical performance. The obtained composite materials contain spinel (space group Fd3¯m) as well as Li-rich layered phases (space group C2/m) as revealed by X-ray diffraction (XRD), HRTEM and cyclic voltammetry investigations. The excellent electrochemical performance of the composite material could be attributed to the structural stability achieved by the integration of spinel and layered components. Selected synthesized composite materials exhibit high discharge capacities close to 200 mAh g−1. The FeSL750 shows better capacity retention (92(3)% at the 50th cycle and 82(5)% at the 70th cycle) and rate capability than the FeSL550 and FeSL650 samples. However, the FeSL850 sample shows different charge-discharge behaviour. The charge capacity corresponding to FeSL850 is found to increase up to the 20th cycle, then stabilizes and displays a capacity retention of almost 100 % at the 50th cycle and 91(1)% at the 70th cycle. The electrochemical mechanism of FeSL750 was elucidated via in operando XAS investigations, which reveal electrochemical activity from all transition metals.

Streamlined fractionation for recovery of high-yield xylo-oligosaccharides, pure lignin and ethanol from poplar using short-chain organic acid/pentanol biphasic system

Biphasic pretreatment offers a sustainable method by integrating the fractionation of hemicellulose, lignin, and cellulose into a single process, thereby enhancing biomass resource utilization while reducing environmental impact. However, this process faces the challenge of diverse hemicellulose products with low added value. This study employed organic acid-catalyzed water/pentanol biphasic pretreatment to selectively convert hemicellulose into xylooligosaccharides (XOS), while simultaneously separating lignin and cellulose. Both the organic acids and pentanol used are biodegradable and compatible. The lactic acid (LA)/pentanol biphasic system was particularly effective for XOS production and lignin removal, attributed to the high acidity of LA and its relatively low partition coefficients in the water/pentanol system, crucial factors influencing hemicellulose and lignin separation efficiency. The XOS yields reached 46.9 %, while the lignin removal rate was 74.6 %. Additionally, LA/pentanol pretreatment significantly enhanced cellulose digestibility, demonstrated by an ethanol production of 54.1 g/L during simultaneous saccharification fermentation at 15 % solids loading. The recovered lignin from the organic phase retained the structural characteristics of native lignin. It also had a low molecular weight and abundant phenolic hydroxyl groups, indicating its suitability for further valorization. Pentanol maintained its performance after four cycles of reuse, demonstrating the stability and reusability of the solvent system. This study highlighted the potential of the LA/pentanol biphasic system for simultaneous hemicellulose conversion and lignin isolation, offering a simplified and sustainable one-step valorization route for biomass.

EFFECTS OF SYNTHESIS TEMPERATURE ON THE STRUCTURAL AND OPTICAL PROPERTIES OF CaAl2O4: Eu2+, Dy3+NANOPARTICLES

Calcium aluminate phosphor nanomaterials co-doped with europium and dysprosium (CaAl2O4: Eu2+, Dy3+) were prepared using a facile solution combustion technique. The structural and optical properties were investigated. The X-ray diffraction (XRD) results confirmed the presence of the monoclinic phase in all the samples, with few impurity phases in the samples synthesized at 300°C and 400°C. The Fourier-transform infrared analysis gave the expected chemical combustion results of the final product with few traces of Ca3Al2O6 impurities at low and very high synthesis temperatures. The XRD patterns displayed diffraction angles of the major peaks shifting to higher 2 theta as the synthesis temperature increased. This is attributed to an increase in particle sizes, which led to an increase in lattice parameters. The intensity of the prominent peak increased up to 500°C due to improved crystal quality. The crystallite sizes of the as-prepared samples were determined using the Debye-Scherrer equation. It was noted that there is variation in the crystallite sizes with synthesis temperature. The UV-Vis graph shows that absorption edges also shifted to lower wavelengths with an increase in synthesis temperature. It was noted that the band gap increased with an increase in synthesis temperature up to 500°C, but at temperature of 1000°C, the band gap was observed todecrease. Scanning electron microscope micrographs showed that the samples had irregular shapes with pores and cracks. The study provides a simple route to synthesize CaAl2O4: Eu2+, Dy3+ phosphors with optimum synthesis temperature, producing the most crystalline sample for use in lighting devices.

All-electrochemical-prepared, efficient and robust superhydrophilic/underwater superoleophobic meshes for synchronously achieving oil-water separation and water-soluble pollutant photodegradation

Superhydrophilic/underwater superoleophobic “water-removing” type membranes can overcome the issue of surface themselves easily fouled or even blocked by oils that seriously affects the oil-water separation capacity and limits the recycle use, and thus attract a great deal of research attention. In this work, we employed the electrochemical deposition method to fabricate Cu3(PO4)2 nanosheets (NSs) vertically grown on a copper mesh (COM) to achieve efficient oil-water separation, followed by the deposition of titanium dioxide (TiO2) nanoparticles and graphitic carbon nitride (g-C3N4) nanosheets on the surface of Cu3(PO4)2 nanosheets-wrapped mesh (Cu3(PO4)2@COM), respectively. The composited meshes of TiO2@Cu3(PO4)2@COM and g-C3N4@Cu3(PO4)2@COM not only showed the considerable superhydrophilic/underwater superoleophobic property in the application of oil-water separation, but also simultaneously exhibited the desirable photocatalytic activity for the degradation of water-soluble pollutants as the water passed through the meshes. The oil-water separation efficiency of TiO2@Cu3(PO4)2@COM and g-C3N4@Cu3(PO4)2@COM can reach as high as 97 % and 96 % that both of meshes have the water flux of various water-oil mixtures above 3250 L/m2h, along with their degradation efficiency of 79 % and 90 % for RhB pollutant under full spectrum light irradiation, respectively. In addition, the as-prepared meshes have the robust, sustainable and stable properties through ten-cycles test of oil-water separation and photocatalytic degradation without significant performance decay. Our primary results provide a potential and simple route to construct multifunctional membrane materials for synchronously achieving water purification in oily wastewater.

A facile and sustainable strategy to construct recyclable paper with enhanced water and oil resistance for eco-friendly food packaging

As a potential substitute for petroleum-based plastics as food packaging material, application of paper is hampered by weak resistance to water and oil. In light of this, paper barrier coating was prepared based on sodium alginate and alkyl ketene dimer. The properties of the obtained SAKD emulsion were investigated and stabilizing mechanism was proposed. Furthermore, SAKD emulsion was applied on paper surface for enhancing barrier properties against both water and oil. After coated, oil resistance KIT was increased from 0 to 8, sizing degree increased by 3977 % and Cobb30 decreased by 66.08 % probably because a more closed structure formed with lower surface energy. Barrier properties to air, water vapor and organic solvents were also strengthened. Additionally, the coating exhibited good stability after folded repeatedly. Furthermore, SAKD coating layer did not negatively affected degradability of paper and the coated paper could be efficiently recycled via a facile treatment, confirming its eco-friendliness. This work demonstrates a sustainable and simple route to prepare paper with good barrier properties and provides the feasibility of developing eco-friendly paper packaging for food based on bio-based materials.

Enhanced supercapacitive performance in Cu doped Sn3O4 synthesized by a simple extract route

The synthesis of nanomaterials using plant extracts is of great importance for a sustainable, chemical-free future. In this study, multivalent Sn3O4 doped with Ni and Cu were synthesized by a simple, low-cost method using Moringa oleifera leaf extract at low temperature and investigated for supercapacitor applications. Various characterizations indicate that the synthesized samples crystallize in a triclinic space group and have a larger surface area of 109.2 m2/g, which is advantageous for electron and ion transport. Electrochemical studies were carried out by cyclic voltammetry, galvanostatic charge/discharge, impedance spectroscopy and cycle life measurements in 6 M KOH electrolyte. Cu-doped Sn3O4 showed the highest capacitance of 608 C/g at a current density of 1 A/g. An asymmetric device built with it delivered an energy density of 31.5 Wh/Kg at a power density of 1400 W/Kg and retained 85 % capacity even after 6000 continuous cycles. The results show that extract-based synthesis of multivalent oxides is beneficial not only for a sustainable environment but also for achieving superior capacity.

Hydrophobic Interface Engineering for Highly Reversible and Stable Zn Anodes

AbstractRechargeable aqueous zinc batteries (AZIBs) with merits of high safety and high theoretical capacity are regarded as next‐generation energy storage devices. However, their practical application is hindered by the instable Zn anodes associated with the dendrite growth, parasite corrosion and side reactions. Developing a stable solid electrolyte interface is crucial for improving the cycling stability of Zn anodes. Herein, a hydrophobic interface is constructed on Zn anode through a simple heptafluorobutyrate acid etching route. The hydrophobic interface containing organic C─F, O─C═O and inorganic Zn─F bonds effectively address the issues of dendrites growth and parasitic reactions. Consequently, symmetric cells with acid‐treated Zn‐HA anodes achieve a prolonged lifespan of over 2000 h at 4.0 mA cm−2 and 1100 h at 10.0 mA cm−2. When paired with MnO2 cathode, the full cells deliver lower overpotential and outstanding cycling stability. This strategy provides a simple and feasible method to construct stable Zn anode for achieving high performance AZIBs.

Efficient structural and compositional modulation of vanadium oxides for high-areal-capacity zinc-ion batteries

Although rechargeable aqueous zinc-ion batteries (RAZIBs) have been revitalized as competitive candidates for large-scale energy storage, the development of this technology is stalled by the underutilization of cathode materials due to sluggish reaction kinetics, resulting in low areal capacities that cannot meet the practical requirements. Herein, this study reveals a simple, efficient, and low-energy synthetic route to effectively convert relatively inactive α-V2O5 (131 mAh g−1 at 0.1 A g−1) into highly active MxV8O20·nH2O (MVO, M = Li, Na, and K) by liquid-phase dissolution-recrystallization reaction and chemical preintercalation under low-temperature conditions. Particularly, NaVO presents the most expansive diffusion channel, the highest specific surface area, and the smallest band gap, allowing faster electron/ion transport kinetics and better material utilization. With these features, NaVO accommodates electrolyte Zn2+ and H+ with good reversibility, showing high capacity (383 mAh g−1 at 0.1 A g−1) and rate-performance (207 mAh g−1 at 8 A g−1). More importantly, high-areal-capacity of 3.2 mAh cm−2 and remarkable cycle stability over 1500 cycles can be achieved from free-standing high-mass-loading electrode (∼14 mg cm−2) made of NaVO and multi-walled carbon nanotubes (MWCNTs). This work enriches the synthetic methods for obtaining high-performance vanadium-based host materials with practical areal capacity and cycle stability.

A simple route of providing a soft interface for PEDOT: PSS film metallic electrodes without loss of their electrical interface parameters

The work presents the development of a soft interface at PEDOT:PSS film without changing its electrical interface parameters. In the first step, PEDOT:PSS is electrodeposited on the commercial platinum electrode under the state-of-the-art conditions desirable for different electrochemical electrodes. Secondly, a pure hydrogel layer is deposited on the top of the electrodeposited PEDOT:PSS film under conditions that provide desirable mechanical properties (Young's modulus ∼10–20 kPa) and high permeability to ions from the solution. As a result, a PEDOT:PSS electrode with a soft interface desirable for different electrode applications is fabricated. The electrode exhibits electrical parameters at the same level as the state-of-the-art PEDOT:PSS film applied already for electrode applications. Moreover, the hydrogel layer additionally supports the polymeric film's electrochemical stability by inhibiting its oxidative degradation. The thickness of PEDOT film does not affect the overall electrochemical properties of the hydrogel electrode. The work shows that the specific choice of the hydrogel type and fabrication conditions allows to synthesis of the hydrogel interface on a stiff polymeric film, which does not block the ionic and electrical transfer. Moreover, the fabricated PEDOT:PSS electrode with hydrogel interface reveals interfacial impedance and potential window comparable or even better to the already published studies on PEDOT:PSS hydrogels.

Innovative Ag@Cu/white sand and polysaccharide based nanocomposites: A simple route to conductive and antibacterial paper coatings

In this work, we presented a simple method for preparing nanocomposite pigments via doping the naturally occurring white sand pigment using silver (Ag) and copper (Cu). The nanocomposites (Ag@WS, Cu@WS, and Ag&Cu@WS) were produced in two suspensions at 25 % and 50 % w/v concentrations, utilizing casein (Cas) and nanostarch (NanoSt) as bio-friendly binders. The prepared nanocomposite pigments were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction crystallography (XRD), and dynamic light scattering (DLS), as well as topographical analysis including scanning electron microscopy (SEM), EDX, and transmission electron microscopy (TEM). The coated paper sheets were characterized using topographical analysis and mechanical, optical, physical, and electrical properties. The antimicrobial activity assay was carried out on the coated paper sheets using the most infectious microbial pathogens. FTIR and XRD analyses confirmed the presence of Cas and NanoSt in the samples. The addition of white sand (WS) and doped nano-metals influenced the crystallographic structure of the polysaccharides. A small amount of Ag, Cu, and Ag&Cu nanoparticles was investigated through EDX. The white sand was a plate structure decorated with spherical Ag, Cu, and Ag&Cu nanoparticles, with an average size of about 147, 105, and 78 nm, as observed from TEM images and DLS. The antimicrobial activity assays revealed that nanocomposite pigment embedded with bimetallic Ag&Cu nanoparticles exhibited a synergistic effect, resulting in enhanced broad-spectrum antibacterial and antifungal activities. The electrical performance of the coated paper was enhanced by using Ag&Cu@WS nanocomposite pigment. Incorporating 50 % Cu@WS into the coating resulted in significant improvements in the mechanical properties of the paper. Specifically, tensile strength increased by 6.3 N/mm, tensile index by 69.06 N m/g, stretching by 1.68 %, tensile energy absorption by 71.4 J/m2, burst strength by 257.75 kPa, and burst index by 2.83 kPa m2/g. Furthermore, incorporating 50 % Ag&Cu@WS increased the opacity to 93.2 % and reduced the roughness of the coated paper by 36 % compared to using 50 % Ag@WS or 50 % Cu@WS alone.