High Conductivity Research Articles

Confined Polyethylene Glycol Anchored in Kaolinite as High Ionic Conductivity Solid-State Electrolyte for Lithium Batteries.

Solid-state electrolytes (SSEs) have garnered significant attention as critical materials for enabling safer, energy-dense, and reversible electrochemical energy storage in batteries. Among the various types of solid electrolytes developed, composite polymer electrolytes (CPEs) have stood out as some of the most promising candidates due to their well-rounded performance. In this study, we choose polyethylene glycol (PEG) as the covalent grafting intercalant and lithium perchlorate as carrier source to prepare a fast lithium ion conductor, K-PEG-Li doped with clay-based active filler as a CPE. The CPE exhibits excellent lithium conduction (4.36 × 10-3 S cm-1 at 25 °C and 3.32 × 10-2 S cm-1 at 115 °C), great mechanical performance with good tensile strength (6.07 MPa) and toughness (strain 313%), and convincing flame-retardancy. These outstanding conducting and mechanical functionalities indicate that such a clay-based active filler doped composite polymer electrolyte will find promising application in solid-state lithium batteries.

A semi-conductive rigid polyurethane foam derived from kraft lignin polyol and a PEDOT: PSS coating

Rigid polyurethane foams (RPUF) are mainly used as thermal insulators materials. These materials are drawing the attention of the emerging sector of the Internet of Things (IoT) due to their features such as good chemical resistance, lightweight, and tunable mechanical properties. Yet, for IoT applications, the electrical conductivity of this type of materials should be increased substantially. To address this challenge, as well as the urgency to use renewable and sustainable resources, semi-conductive RPUF were synthesized using crude lignin-based polyol (LBP) doped with multi-walled carbon nanotubes (MWCNT) and coated with PEDOT: PSS, using the dip coating technique. The ensuing semi-conductive RPUF has low density (33–34 kg/m3), high electrical conductivity (in the order of magnitude of 10−5 S/m), and a stretchability enhancement of almost 50 % upon coating with PEDOT: PSS. Furthermore, the mechanical performance of RPUFs can be adjusted using MWCNT and fine tuning of the formulation. Lignin being an abundant natural aromatic polyol allows the partial replacement of fossil derived polyols in the production of RPUFs and its aromatic structure contributes to the thermal and mechanical stability of the ensuing foams.

Fabric-based lamina emergent MXene-based electrode for electrophysiological monitoring

Commercial wearable biosignal sensing technologies encounter challenges associated with irritation or discomfort caused by unwanted objects in direct contact with the skin, which can discourage the widespread adoption of wearable devices. To address this issue, we propose a fabric-based lamina emergent MXene-based electrode, a lightweight and flexible shape-morphing wearable bioelectrode. This work offers an innovative approach to biosignal sensing by harnessing the high electrical conductivity and low skin-to-electrode contact impedance of MXene-based dry electrodes. Its design, inspired by Nesler’s pneumatic interference actuator, ensures stable skin-to-electrode contact, enabling robust biosignal detection in diverse situations. Extensive research is conducted on key design parameters, such as the width and number of multiple semicircular legs, the radius of the anchoring frame, and pneumatic pressure, to accommodate a wide range of applications. Furthermore, a real-time wireless electrophysiological monitoring system has been developed, with a signal-to-noise ratio and accuracy comparable to those of commercial bioelectrodes. This work excels in recognizing various hand gestures through a convolutional neural network, ultimately introducing a shape-morphing electrode that provides reliable, high-performance biosignal sensing for dynamic users.

Doped double spirocyclic cationic POSS for nanocomposite anion exchange membranes with high conductivity and robustness

Organic-inorganic hybridization methods are receiving increasing attention as a method that can improve the performance of anion exchange membranes (AEMs) in a simpler and more effective way. Here, by selecting polyhedral oligomeric silsesquioxane (POSS) with good mechanical and thermal properties as inorganic fillers. Successful introduction of N-spirocyclic cations with bifunctional groups onto POSS yielded MDSU-poss. subsequently, we doped them into qPTP-IC-O-9% membranes as fillers in different ratios to obtain a series of composite membranes. High-density cations introduced by POSS with simultaneous organic-inorganic frameworks effectively inhibit membrane over-swelling. As a result, the membrane is able to achieve high ionic conductivity with the assurance of reasonable dimensional stability. At 80 °C, the 15% MDSU-poss/qPTP-IC-O membrane achieved the ionic conductivity of 168.6 mS cm-1 at low SR with the peak power density of 431 mW cm-2. In addition, the mechanical properties of the composite membranes were all greatly improved due to the organic cations attached to the POSS with good affinity, contributing to the tensile strength of the 15% MDSU-poss/qPTP-IC-O membrane of 57.4 MPa. The membrane was finally immersed in 3 M NaOH solution for 1032 h and still maintained 89.3% of the starting ionic conductivity.

Robust self-healing ion-conductive interlocking dual-network binder based on gradient dynamic bonding for advanced SiO anodes in Li-Ion batteries

Silicon-based (e.g., SiO) anodes have attracted much attention for their high specific capacity; however, poor conductivity and dramatic volume change during the charge/discharge cycling hinder their commercial application in high energy density lithium-ion batteries (LIBs). Ideal binders hold a decisive effect on inhibiting the volume effect of the silicon-based anode. Herein, inspired by the hierarchical structure of living organisms, we design a multifunctional self-healing interlocking dual-network binder based on gradient dynamic bonding and apply the binder to SiO anode toward high specific capacity and long-term cycle performance. Specifically, rigid polyacrylic acid (PAA) and flexible polylipoic acid (PTA) are interlocked by gradient dynamic bonding containing of disulfide linkage, metalcoordination and hydrogen bonding. The obtained binder has strong adhesion, high mechanical toughness, fast self-healing performance and high ionic conductivity, which enable the SiO anode effectively buffering the volume expansion and exhibiting excellent cycling stability. The SiO electrode with the new binder delivers a high capacity of 884.8 mAh/g at a current density of 0.5 A/g after 500 cycles and a high capacity of 765.2 mAh/g at a high mass loading of 3.0 mg cm−2 after 100 cycles. Moreover, the assembled SiO||NCM811 full cell achieves a reversible capacity of 169.75 mAh/g with capacity retention of 77.5 % after 100 cycles. This work offers a new method for the design of versatile self-healing binder adaptive to electrode volume change, so as to accelerate the application of the silicon-based anode.

Unravelling the O-doping effect on chemical/electrochemical stability of Li5.5PS4.5Cl1.5 for all-solid-state lithium batteries

Chlorine-rich Li-argyrodite sulfide solid electrolytes Li5.5PS4.5Cl1.5 are applied in all-solid-state batteries (ASSBs) due to the promising ionic transport and structural stability. However, the poor air/moisture stability and incompatibility to Li metal impede their practical applications. Herein, we synthesized a Li5.5PS4.5Cl1.5-based argyrodite exhibiting improved moisture stability and electrochemical performance to metallic Li, as well as high-voltage cathodes through O doping. The prepared oxygen-doped Li5.5PS4.5Cl1.5 samples (Li5.5PS4.425O0.075Cl1.5) possess significantly enhanced air stability and lower migration barrier in comparison with pristine Li5.5PS4.5Cl1.5. Moreover, Li5.5PS4.425O0.075Cl1.5 exhibits lower polarization voltage and better compatibility with lithium metal in the constant current charge-discharge tests of Li-Li symmetrical cell. This is attributed to the Cl-O coexistence coating interface that observed in the interface of Li/Li5.5PS4.425O0.075Cl1.5. To fully leverage the ultrafast ionic conductivity of Li5.5PS4.5Cl1.5, we construct ASSBs using optimized Li5.5PS4.425O0.075Cl1.5 as buffer layer between pristine LiNi0.6Mn0.2Co0.2O2 cathode materials and Li5.5PS4.5Cl1.5, leading to higher discharge capacities and elevated capacity retention. Based on above results, we further introduce LiNbO3-coated LiCoO2 as cathode, combined with Li5.5PS4.425O0.075Cl1.5 as an isolating layer between Li anode and Li5.5PS4.5Cl1.5 to suppress the growth of Li dendrite and achieve superior cyclability at wide voltage windows. Consequently, the all-solid-state lithium batteries exhibit promising application in a wide temperature range. This work provides a compelling strategy for achieving improved Chlorine-rich Li-argyrodite solid electrolytes with excellent air stability, high ionic conductivity and Li dendrite suppression capability, hence enabling all-solid-state batteries with high energy density and superior cyclability.

Ultra-strength and anti-freezing zwitterionic hydrogels with high ion conductivity: Effect of the hydrophobic monomer in hydrogels mechanical properties

Ultra-strength and anti-freezing zwitterionic hydrogels with high ion conductivity: Effect of the hydrophobic monomer in hydrogels mechanical properties

Lithium p-toluenesulfinate-coated poly(imide) separators for enhanced safety and electrochemical performances of lithium-ion batteries

Increasing the energy density of lithium-ion batteries enhances their applicability; however, ensuring their safety remains a critical issue in the energy society. Herein, we report the development of a lithium p-toluenesulfinate (PTSL)-coated polyimide (PI) separator with improved safety and electrochemical performance during cycling. It is anticipated that integrating PTSL particles into the PI separator will mitigate the risk of internal short circuits by clogging the porous structure of the PI separator and enhance the interfacial stability of the electrode materials. The PTSL is expected to act as an effective component of protective layers, physically separating the cathode from direct contact with electrolytes. The PTSL-embedded PI separator regulated the porous structure inherent to the PI separator, thereby enhancing its physical and thermal properties, such as improved wetting characteristics (evidenced by higher ionic conductivities and lithium-ion transference numbers) and thermal behaviors (reduced shrinkage and more stable thermal decomposition behaviors). During cycling, the cells with the PTSL-coated PI separator demonstrated increased cycling retention compared to the cells with graphite/NCM811 electrodes because the additional PTSL-based protective layers mitigated the electrolyte decomposition upon cycling.

Design of 3D vapor chamber for thermal management of permanent magnet synchronous motors

The vapor chamber is a high thermal conductivity device with significant potential for enhancing the power density of permanent magnet synchronous motors. Practical installation requirements and the heat curing process of thermal conductive adhesive impose strict demands on vapor chambers, such as precise 3D profiles and resistance to expansion. This paper presents a novel 3D wave vapor chamber with high thermal conductivity, a design not previously reported. Special internal support structures are engineered to ensure the vapor chamber with performances of thermal conductivity, anti-expansion, and bendability. Simulation results show an anti-expansion deformation of 6.28 % at 125 °C. Heat transfer experiments demonstrate that the 3D vapor chamber achieves an effective thermal conductivity of 4426.73 W/m·K and a thermal resistance of 0.136 °C/W under a 100 W heating load. Furthermore, the 3D vapor chamber-based cooling strategy manages a heat load of 143.93 W at a cutoff temperature of 90 °C, marking an 82.1 % improvement over traditional cooling methods.

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.

Sustainable and high performance MXene hydrogel with interlocked structure for machine learning-facilitated human-interactive sensing

Wearable epidermal electronics fabricated from MXene-based conductive hydrogels have attracted considerable interest because of their promising prospects in real-time health monitoring and human–computer interaction sensing. However, the development of a sustainable hydrogel with exceptional mechanical toughness, high conductivity, and self-adhesion is crucial to reliably capture signals through polymer network designs that establish robust interactions between MXene nanosheets and network substrates while minimizing electronic waste generated by discarded sensors. This study presents the fabrication of a sustainable conductive MXene-based dual-network hydrogel through skillful assembly of MXene nanosheets, β-cyclodextrin with azobenzene-modified polyacrylic acid chains, and poly (vinyl alcohol) polymer networks. The hydrogel demonstrates exceptional mechanical properties (strength at breaking ∼ 625 kPa, elongation at break ∼ 630 %) attributed to the presence of numerous hydrogen bonds and host–guest interactions, along with superior electrical conductivity (23.65 S/cm) and self-adhesion. The hydrogel demonstrates exceptional sensitivity across a wide range of strains, enabling the detection of various human movements and achieving successful applications in handwriting recognition and sign language translation. Under acidic condition and UV irradiation, the disassembly of AZO and β-CD as well as the untangling of PVA chains entanglement facilitate the release and recycling of MXene. This study presents a technological platform that holds promise for developing conductive hydrogels with enhanced sensing capabilities, catering to the requirements of stretchable electronic skin and intelligent robotic systems.

Zero-valent iron on graphite-cellulose biochar catalysts for the Fenton degradation of tetracycline from water

Tetracycline (TC), an antibiotic widely used in the treatment of animal and human diseases and promotion of animal growth. However, its uncontrolled discharge to water sources can also cause the promotion of antibiotic resistant bacteria and genes. In this study, graphite and cellulose were used as raw materials to construct a graphite-biochar (G-BC) by carbothermal reactions. This graphite-biochar was subsequently mixed with ZVI with various mass ratios by ball milling to produce graphite-biochars supported ZVI (ZVI/G-BC) catalysts, further used in the heterogeneous Fenton degradation of tetracycline. The materials were fully characterized by different techniques. The removal of TC by BC, G-BC and ZVI/G-BC was tested under different reaction conditions. The best synthesis conditions were achieved at a heating temperature of 700 °C, a graphite content of 20 %, a ball milling speed of 500 rpm, a ball milling time of 5 h, as well as a G-BC and ZVI mass ratio of 1:3. Graphite improves the conductivity and micropore area of the material, which enhances the removal of TC by ZVI/G-BC catalysts in Fenton-like reactions. TC was first oxidized to intermediate products and then further mineralized to CO2 and H2O. The best TC removal performance was obtained with a catalyst dosage of 1.1 g·L1, a hydrogen peroxide concentration of 140 mM and an initial pH value of 3. The reaction data fitted properly a pseudo first-order kinetic equation. TC removal as high as 91 % was achieved even in the 3rd round of reuse. This study reports a novel ZVI material with high conductivity and good TC removal performance.

Electrolyte-triggered in-situ polymerization of multi-site organic cathodes for superior-longevity cation-anion co-storage secondary batteries

Organic electrodes are promising as next-generation energy storage materials owing to their diverse structures, low mass, and environmental friendliness. Nevertheless, the dissolution and degradation of organic active species in electrolytes are remaining obstacles to their authentic commercialization. Herein, we report an instantaneous in-situ upgrading strategy to convert multi-site organic cathode materials, e.g., 1-aminoanthraquinone (1-AAQ) and 1,5-diaminoanthraquinone (1,5-DAAQ), into poly(1-aminoanthraquinone) (PAAQ) and poly(1,5-diaminoanthraquinone) (PDAAQ) simply by dropping the electrolyte during battery assembly without extra operations. The remarkable chemistry is essentially a chemical polymerization process of redox-active organic monomers triggered by the electrolyte containing magnesium bis(hexamethyldisilazide) (Mg(HMDS)2) as an initiator. Notably, due to the π-conjugated polymer chain with inhibited dissolution, high conductivity, and improved stability, the as-obtained PDAAQ cathode delivered a high specific capacity (254 mAh/g at 100 mA/g), superior rate performance (83 mAh/g at 2000 mA/g), and excellent cycling stability for over 8000 cycles accompanied by an average capacity decay of only 0.0026 % per cycle. Detailed characterizations further explore the kinetic behaviors and verify a reversible hybrid cation–anion co-redox mechanism of PDDAQ cathode, which involves reversible Mg2+ cation insertion/extraction on AQ units and anion doping/de-doping reactions on the PANI backbones. Density functional theory (DFT) computations demonstrate the optimized structure of the discharged products and indicate that Mg2+ preferably interact with two carbonyls oxygen atoms and nitrogen atom for both PAAQ and PDAAQ. This study demonstrates an intriguing in-situ chemical-polymerization synthetic approach for preparing multi-site organic electrode materials that compromise structure optimization and synthetic efforts, offering great promise for high-performance and sustainable secondary batteries.

Design of non-heat-treatable Al-Fe-Ni alloys with high electrical conductivity and high strength via CALPHAD approach

Electrical conductivity and strength are two critical properties concerned for rotors materials in electric vehicles. However, the two properties are often mutually exclusive in cast Al alloys. The present work proposes a novel non-heat-treatable Al-Fe-Ni alloy by considering the intermetallic compound’s content and morphology. With the modification of Ni and Fe content, the solidification path of designed alloy were calculated to predict the phase composition, which would greatly impact their performance. The as-cast Al-2Fe-1Ni (wt.%) alloy exhibits comprehensive properties with an ultimate tensile strength of 131.2±2.5MPa, an elongation of 20.2±3.6% and an electrical conductivity up to 52.0±0.1%IACS. The eutectic microstructure of Al13(Fe,Ni)4+α-Al in Al-2Fe-1Ni alloy accounts for over 90%, much larger than the eutectic content in Al-0.4Fe-3.4Ni and Al-1Fe-1Ni alloys. The fine eutectics in Al-2Fe-1Ni alloy improve the second-phase strengthening effects and plastic deformation capability. In addition, the fibrous rod-like intermetallic reduces the electron scattering during the propagation process and leaves more space for free electron movement. The dominant second phase transforms from Al3Ni phase to Al9FeNi phase, further enhancing the thermal stability of the alloy. After aging treatment at 180 °C for 100h, it shows no noticeable change in electrical conductivity and mechanical properties. It is hoped that this work can provide a new design approach for high-strength and high-conductivity Al alloys.

A bio-based, self-healable, conductive rubber film with oxidized cellulose nanofiber segregated network

Rubber composites are indispensable in all areas of our daily lives. However, the formation of permanent crosslinked networks in rubber materials makes it difficult to recycle, resulting in a non-negligible waste of resources. In this paper, a vulcanization-free, fully bio-sourced rubber composite was prepared by using oxidized natural rubber (oNR) and oxidized cellulose nanofibers (TOCFs). TOCFs are selectively dispersed between the latex particles to form a segregated network. Meanwhile, the formation of hydrogen-bonding between oxygenated polar groups of oNR and abundant hydroxyl and carboxyl groups of TOCFs improves their interfacial interactions. This special structure promotes strain-induced crystallization (SIC) behavior of oNR matrix, giving its tensile strength up to 14.7 MPa. Furthermore, the oNR/TOCFs film shows excellent self-healing efficiency (96 %) at 40 °C for 5 h. The hygroscopicity of the TOCFs segregated network can turn the oNR/TOCFs film to be a conductive film by regulating the absorbed water content. The film has high conductivity (0.05 S/m) at a water content of 8.99 wt%, and the resistance change (RV/R0) can be varied between 1–5.9 × 10−6 at a water content range of 0–8.99 wt%, which makes it have potential for a wide range of humidity monitoring applications.

In situ growth of Cd0.6Zn0.4S on graphene guided by ion anchoring for boosting hydrogen production

Owing to its large specific surface area and high conductivity, reduced graphene oxide (RGO) serves as an ideal platform for electron transfer. In this study, in situ growth of sulfides on RGO was attributed to metal ion anchoring on graphene oxide nanosheets by electrostatic attraction between negatively charged functional groups and metal ions. Tight binding between sulfides and RGO caused by in situ nucleation and growth can promote direct electron transfer and electron-hole separation, which is a more effective way to enhance hydrogen evolution activity. Cd0.6Zn0.4S/graphene (CZS/RGO) composite photocatalysts with different graphene ratios were prepared and exhibited high photocatalytic activity due to the improved dispersion of CZS and increased electronhole separation. The hydrogen production rate of CZS-0.8/RGO reached 52.50mmol∙g–1∙h–1, and after nine cycles for 27h, the hydrogen production efficiency remained at 86.4%.

Decoupling the roles of grain boundary strength and grain size hidden in grain-level electro-chemo-mechanical failure of solid-state electrolyte

Garnet lithium lanthanum zirconium oxide (Li7La3Zr2O12, LLZO) is a benchmark solid-state electrolyte material receiving considerable attention owing to its high conductivity and chemical stability against Li metal. Although its electro-chemo-mechanical failure mechanisms have been much investigated, the equivocal roles of grain boundary strength and grain size of LLZO remain under-explored, hindering further performance improvements. Here we decoupled the effects of grain size and grain boundary strength of polycrystalline LLZO via the combination of electrochemical kinetics and the cohesive zone model. We discovered that the disintegration of LLZO is initiated by the accumulation of local displacements, which strongly relates to the changes in both grain size and grain boundary strength. However, variations in grain boundary strength affect the diffusion and propagation pathways of damage, while the failure of LLZO is determined by the grain size. Large LLZO grains facilitate transgranular damage under low grain boundary strength, which can alter local chemo-mechanics within the bulk of LLZO, leading to more extensive damage propagation. The results showcase the structure optimization pathways by preferentially controlling the growth of lithium dendrites at grain boundaries and their penetration in garnet-type SSE.

Nitrogen Functionalised Biomass Derived Mesoporous Carbon Nanomaterials for Electrochemical Detection of Lead (II) Ions

This study has explored the sustainable solution after designing an economical metal-free biomass-derived nanocarbon for the selective sensing of lead. The nitrogen and sulfur-rich mesoporous nanocarbon is designed through a facile hydrothermal-assisted thermal annealing method. The high-temperature treatment gave nanocarbon unique carbon dot decorated layered morphology, while nitrogen and sulfur precursor thiourea and melamine strengthened the nanomaterial stability, sensitivity, and selectivity toward lead metal ions. The high specific surface area of mesoporous nanocarbon viz., 1671.93 m2/g with the pore width and pore volume of 2.02 nm and 0.476 cm3/g has enhanced the conductivity of as-synthesized sensor, which helps in increasing sensitivity toward lead. The high conductivity was also confirmed through cyclic voltammetry, where an 80 % increment in current was observed in the case of the modified electrode when compared with bare GCE. The differential pulse normal voltammetry and differential pulse anodic stripping voltammetry were performed to calculate the detection limit, where an excellent detection limit of 22 nM was obtained from the DPASV technique. Moreover, the nanomaterial was also tested for detecting lead in tap water. The as-synthesized nanocomposite is highly efficient and selective for the detection of lead. This study will motivate the researchers to engineer sustainable and efficient devices for sensing metal pollutants.

Smartphone-based electrochemical sensing of propyl gallate in food samples by employing NiFe-Oxide decorated flexible laser-induced graphene electrode

Flexible graphene electronics utilizing laser-induced graphene (LIG) technology offer an efficient, cost-effective, and mask-free approach to produce graphene in a single step. LIG can be directly patterned on polyimide films, impacting their surface properties, chemical composition, and electrical conductivity. However, the electrochemical performance of standalone LIG is limited. To address this, the study enhances LIG by synthesizing nickel-iron Prussian blue analogues through co-precipitation and calcination, forming porous NiFe-Oxide, which is subsequently deposited onto the LIG surface via a facile physical deposition method. The porous NiFe-Oxide@LIG electrode material demonstrates excellent electrochemical sensing capabilities due to its high conductivity, improved surface area, enhanced active sites, and superior electrocatalytic performance for detecting the antioxidant propyl gallate (PG). This porous NiFe-Oxide@LIG electrode material features a linear detection range (0.5-5μM), low detection limit (0.01μM), high sensitivity (17.12 μAμM-1cm-2), and strong selectivity for PG. Additionally, it offers high reproducibility and repeatability, evidenced by the low relative standard deviation values of 2.61% and 1.96%, respectively. The practicality of the proposed sensor was validated using food samples, integrated into a smartphone-based sensing device, achieving satisfactory recovery rates above 79.2%. This smartphone-based sensor enables effective onsite food quality and safety monitoring.

Highly efficient oxygen carrier NiFeP (oxy) hydroxides nanoparticle embedded in N-doped porous carbon derived from bio-waste for bifunctional electrocatalysts

Developing cost-effective, readily available materials for efficient hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water splitting is a crucial step toward enhancing the profitability and sustainability of energy conversion systems. This research introduces a novel synthesis method for NiFeP/NPC OHs from banana peel bio-waste, a method that could revolutionize the field of materials science and electrochemistry. The use of metallic phosphides, known for their excellent electrical conductivity and catalytic activity, as bifunctional catalysts, combined with the efficient synthesis of nanoporous carbons (NPC) from banana peel bio-waste (BPW), could pave the way for a new era of sustainable and cost-effective energy conversion. By chemically activating different porogens, such as nickel, iron, and phosphorus (NiFeP), to form (oxy) hydroxides (OHs), functional carbonaceous structures with a high density of pores and large specific surface areas can be achieved. The resulting materials, designated as NiFeP/NPC OHs, are characterized by their remarkable porosity, high conductivity, large surface area, and chemical stability. These properties make NiFeP/NPC OHs particularly suitable for electrocatalysis, where they exhibit outstanding activity in both HER and OER. The optimized NiFeP/NPC OHs material shows a very low overpotential of 93 mV for HER and 243 mV for OER at 10 mA cm⁻2 and high durability over 100 hours. Moreover, the bifunctional NiFeP/NPC OHs electrode demonstrates exceptional catalytic activity and stability in alkaline solutions. This study not only highlights the innovative synthesis of NPC from BPW and the cost-effective fabrication of NiFeP/NPC OHs but also sparks curiosity about the potential of this novel synthesis method.