Advanced Electrode Research Articles

Integration of membrane bioreactor with a weak electric field: Mitigating membrane fouling and improving effluent quality targeting low energy consumption

The electrical assisted MBR (EMBR) has been employed to improve the water quality and solve the fouling problem. However, advanced material-based electrodes or high operation voltage bring difficulties for the practical application of EMBR. Herein, a weak electric field generated by titanium electrodes was employed to establish an EMBR and the fouling mechanism was investigated in detail. The results showed that introduction of a weak electric field at voltage of 0.1 V/cm and current density of 7 μA/cm2 efficiently decreased the extracellular polymeric substances (EPS) content by over 40 % as such extended the service time of MBR by more than 20 %. Specifically, the weak electric field reduced the relative abundance of Bacteroidetes, known for secreting proteinaceous EPS, by 38.61 %, and increased relative abundance of Patescibacteria with EPS decomposition by 6.73 times, thus effectively reducing the EPS concentration. Further KEGG pathway analysis revealed that electric field accelerated enzymatic reactions and promoted microbial metabolism of carbohydrate and amino acid. Furthermore, this weak field reduced the sludge deposition on membrane by increase of the electrostatic repulsion and the irreversible fouling was mediated. According to the composition of the fouling layer, a corresponding cleaning scheme was applied. This EMBR consistently produced high-quality effluent in all cycles, with 99.31 % COD, 98.73 % NH4+-N, 85.87 % TP and 92.66 % TN removals. In conclusion, the weak electric field endow EMBR exceptional anti-fouling ability and superior effluent quality under lower energy consumption.

NH4+ intercalated 1T/2H hybrid MoS2@AlOOH for long-term aqueous ammonium-ion storage

Here, linked by the supramolecular structure between O and S atoms, 1T/2H hybrid MoS2 growing on a layered carambola-like AlOOH substrate (MoS2@AlOOH) is designed as an advanced electrode for developing innovative aqueous ammonium-ion storage to boost its long-term stability. During the composite assembling process through an effortless hydrothermal methodology, the active, aggregation-free AlOOH can induce partial 2H–MoS2 to be 1T-MoS2 and greatly enhance MoS2's long-term stability for NH4+ storage. The 1T/2H hybrid MoS2@AlOOH petal can remains 76.8 % after 14,000 cycles in three electrode system at a large scan rate of 100 mV s−1, significantly superior to the representative MoS2 nanosheet. Remarkably, the intercalation effect of NH4+ can enlarge the interlayer space (0.84 nm) of 1T/2H hybrid MoS2@AlOOH throughout the charging and discharging process, revealing that the NH4+ intercalation can achieve the further shaping of 1T-MoS2 and make MoS2 become efficient endurable. Overall, this work could shed some light on a straightforward but efficient method for fabricating 1T MoS2 hybrid electrode compound that are useful for ammonium-ion storage.

Over-Lithiation Regulation of Silicon-Based Anodes for High-Energy Lithium-Ion Batteries.

Mitigating the growth of dendritic lithium (Li) metal on silicon (Si) anodes has become a crucial task for the pursuit of long-term cycling stability of high energy density Si-based lithium-ion batteries (LIBs) under fast charging or other specific conditions. While it is widely known that Li metal plating on Si-based anodes may introduce inferior cycling stability and cause safety concerns, the evolution of the anode/material structure and electrochemical performance with Li metal plating remains largely unexplored. A comprehensive quantitative investigation of the hybrid Li storage mechanism, combining the Li alloying/dealloying mechanism and plating/stripping mechanism, has been conducted to explore the effect of Li plating on Si-based anodes. The findings reveal that Li plating/stripping accounts for the decay of the overall Coulombic efficiency and cycling stability of the hybrid Li storage mechanism. Furthermore, alloying reactions occurring below 0 V encourage the formation of crystalline Li15Si4, which subsequently exacerbates voltage hysteresis. The performance decay is amplified as the ratio of Li plating/stripping capacity increases, or in other words, as the over-lithiation level rises, thereby posing a threat to the battery's cycling stability. These results provide valuable insights into the design of advanced Si-based electrodes for high energy density LIBs.

In Situ Fabricated Poly(1,8‐naphthalenediamine)/Active Carbon Composite Cathodes for Aqueous Zinc‐Ion Batteries with High Active Sites Utilization and Ultralong Life Span of 50 000 Cycles

AbstractPolymers with redox activity are one type of promising candidates of cathode materials for aqueous Zn‐ion batteries due to their potential low‐cost, high safe, and renewable features. Unfortunately, suboptimal polymer electrode structure often results in unsatisfactory electrochemical performance. Herein, poly(1,8‐diaminonaphthalene)/active carbon composite electrodes are prepared via nanoconfined in situ electropolymerization within porous active carbon, which have ultrahigh specific surface area (1035.0 m2 g−1) and unique nano‐porous structure, thereby highly enhancing the utilization of the active site up to 91.6%. The as‐prepared cathodes deliver ultrahigh reversible capacity of 479.5 mAh g−1, ultrafast rate capability of up to 60 A g−1 and an ultralong life span of 50,000 cycles. Storage mechanism investigation indicates that the cathode material involves a bipolar‐type behavior. These encouraging results demonstrate that nanoconfined in situ electropolymerization in active carbon is a brand‐new strategy for the design of advanced polymer electrodes for high‐performance aqueous Zn‐organic batteries.

Pristine Metal‐Organic Frameworks for Sodium‐Ion Batteries: Past, Present, and Future

AbstractOwing to their adjustable redox‐active sites, designable structures high porosity, and fully activated organic ligands, pristine metal‐organic frameworks (MOFs) have been widely utilized as advanced electrode materials (i. e., both anodes and cathodes) for sodium‐ion batteries (SIBs) to satisfied the insertion/extraction larger size and mass of Na+ cations, achieving significant progresses with excellent electrochemical performance in electrochemical energy storage devices. Here, the recent advances on pristine MOFs as anodes and cathodes for SIBs are summarized. A thorough investigation delves into the detailed characteristics, energy storage mechanisms, and electrochemical performance of diverse pristine MOFs for SIBs are also clarified. Furthermore, the outlooks on pristine MOF electrodes in SIBs are also provided.

Parametric analysis on the apparent purity of Ni powder synthesized via hydrazine-reduction of aqueous NiSO4

The present research focuses on the synthesis of high-purity nickel powder through solution-based chemical reduction using hydrazine hydrate as a reducing agent. A series of synthesis experiments were carried out with variations in the concentration ratio of hydrazine to nickel ions ([N2H4]/[Ni2+] = 5–15), the concentration ratio of hydroxyl ions to nickel ions ([OH−]/[Ni2+] = 10–20), temperature (T = 60–80 °C), and reaction time (t = 30–90 min). The Taguchi L9 design of experiments and analysis of variance (ANOVA) was used to identify the role of the hydroxyl-to-nickel ion ratio ([OH⁻]/[Ni2⁺]) in determining the apparent purity of the nickel powder. The highest apparent nickel powder content, which was 92.75 %, was obtained in the experiment with [N2H4]/[Ni2+] = 5, [OH−]/[Ni2+] = 12.5, T = 60 °C, and t = 30 min. The optimum conditions that significantly influence the apparent purity of nickel powder derived from data processing are used as the basis for the second stage of the experiment to determine the effect of the [OH−]/[Ni2+] ratio on particle size, morphology, and purity of the synthesized nickel powder. It was found that higher hydroxyl concentrations lead to finer particles, and the morphology of nickel particles is linked to their apparent purity, with the chain of beads of nanoparticle aggregates morphology achievable when [OH−]/[Ni2+] = 12.5 and [OH−]/[Ni2+] = 15. The presented results may contribute to filling the gap in the knowledge to synthesize high-purity nickel powder with controlled size and morphology, which can be used in various applications such as catalysts, conductive fillers, and advanced electrodes.

Polyaniline layered N-doped carbon-coated iron oxide nanocapsules for extremely active Li-ion battery anode and oxygen evolution reaction

We report the effective synthesis of polyaniline (PANi)-layered nitrogen-doped carbon-coated Fe3O4 (FNC@PANi) nanocapsules (NCs) for electrocatalysis of oxygen evolution reaction (OER) as well as anode material for lithium (Li)-ion batteries (LIBs) via a simple hydrothermal method and oxidative polymerization technique. The prepared FNC@PANi NCs revealed a dual core-shell structure, in which an intermediate carbon layer allowed excellent electrical conduction between the Fe3O4 NCs and PANi. The dual core-shell structure also allowed the Fe3O4 NCs to expand freely during the Li-ion insertion/extraction and OER processes without breaking the outer layer, thus providing a high surface area (147.85 m2 g−1) and enhanced electrical conductivity. These properties facilitate the application of the dual core-shell FNC@PANi NCs as an advanced electrode material for LIBs, delivering a high reversible specific capacity of 1556.48 mAh g−1 at 0.1 A g−1, excellent rate performance (896.96 mAh g−1 at 1 A g−1), and durable cycling life (680.12 mAh g−1 at 5 A g−1 for 3000 cycles). The dual core-shell FNC@PANi NCs exhibited high electrocatalytic activity in the OER, with a small Tafel slope of 108.7 mV dec−1 owing to synergistic effects between the copious active sites of the Fe3O4 NCs and the carbon core-shell structure and a modest overpotential of 219 mV at 10 mA cm−2. The electrodes showed excellent stability over 10 h, as determined by chronopotentiometry at 10 mA cm−1. The resultant dual-core-shell FNC@PANi NCs are efficient iron-oxide-based electrode materials for LIBs and OER electrocatalysts.

β-Ni(OH)2 nanoparticles@activated sugarcane bagasse carbon nanocomposites as an advanced hybrid electrode material for asymmetric supercapacitors

β-Ni(OH)2 nanoparticles (NPs)@activated sugarcane bagasse carbon (ASBC) nanocomposites (N@ASBC NCps) with different Ni loadings were synthesized using a hydrothermal process. The products were characterized using techniques such as X-ray diffraction (XRD), field emission scanning and transmission electron microscopy (FE-SEM and TEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). Electrochemical performance of the products was studied. Interestingly, the maximum specific capacitance of 1213.32 F/g at 1 A/g could be achieved in a 3N@ASBC NCps positive electrode. Concurrently, the ASBC negative electrode revealed a high specific capacitance of 233.34 F/g at 1 A/g. Additionally, the fabricated asymmetric supercapacitor (ASC), ASC-ASBC//3N@ASBC NCps, had a specific capacitance (Csc) of 34.03 F/g at 1 A/g with a specific energy density (Ed) and specific power density (Pd) of 9.93 Wh/kg and 181.26 W/kg, respectively. Moreover, the device could maintain 69.47% of its capacity after a 5000-cycle test.

Design and Fabrication of Island‐Like CoNi2S4@NiCo‐LDH/Biomass Carbon Heterostructure as Advanced Electrodes for High‐Performance Hybrid Supercapacitors

AbstractThe utilization of heterostructured electrodes offers an effective approach to boost the energy density of supercapacitors without sacrificing their power density. However, the adoption of such materials is frequently impeded by sluggish reaction kinetics. Herein, an island‐like CoNi2S4@NiCo‐layered double hydroxide/biomass carbon (CoNi2S4@NiCo‐LDH/BC) heterostructure is synthesized by embedding CoNi2S4 in the interlayer of NiCo‐LDH nanosheets on BC through a partial in situ sulfidation process. Theoretical and experimental analyses indicate that this unique structural configuration lowers transport barriers and enhances ion adsorption capacity, leading to a significant improvement in ion/electron reaction kinetics. In addition, the embedded structural design effectively alleviates the significant volume expansion during charge–discharge process, while the robust BC framework prevents electrode degradation, thereby enhancing stability. These advantages enable the developed electrode material to achieve a high specific capacity (1655.75 C g−1 at 1 A g−1) and an extended cycle life (86.82% capacity retention after 10 000 cycles). Significantly, the assembled hybrid supercapacitor CoNi2S4@NiCo‐LDH/BC// activated carbon demonstrates a remarkable energy density of 95.57 Wh kg−1 at 866.61 W kg−1 and exceptional cycling stability, maintaining 95.16% capacity after 10 000 cycles. This research offers an effective strategy to promote ion/charge transfer and adsorption capacity of heterostructure and provides a new approach to the development of advanced supercapacitor electrodes.

Construction of advanced Nb9VO25 electrode material by introducing graphene quantum dot for high energy supercapacitors with exceptionally high diffusive capacitance

Unreasonable tunnel structure and low intrinsic conductivity limit practical applications of niobium oxide in high-performance supercapacitors. The study reports the construction of Nb9VO25 electrode material via coordination of Nb(V) and V(V) with histidine and serine-functionalized and boron-doped graphene quantum dot (HSBGQD) and subsequent annealing. The introduction of HSBGQD and rambutan peel leads to formation of small Nb9VO25 nanocrystal and low valent Nb and V species. The combination of small size and more reasonable tunnel structure accelerates the ion diffusion. The Nb(IV) and V(IV) double doping optimizes the tunnel structure, narrows the bandgap and creates new pathways for high-speed electron transfer. The integration of defect engineering with graphene surface modification enhance the intrinsic conductivity. The Nb9VO25 electrode shows exceptionally high specific capacitance of 2925.3 F/g, which is more than 142 times that of Nb2O5. The symmetrical supercapacitor with Nb9VO25 electrodes and PVA/Li2SO4 gel electrolyte offers high specific capacitance (263 F/g at 1 A/g), high-rage capacity (138 F/g at 50 A/g), cycling stability (capacitance retention of 99.4 % after 10000-cycle), energy density (146 W h Kg−1 at 996 W Kg−1 and 77 W h Kg−1 at 50181 W kg−1) and broad application prospect in wearable electronic devices.

Effect of Aggregation Structure on Capacitive Energy Storage in Conducting Polymer Films.

Conducting polymers (CPs), a significant class of electrochemical capacitor electrode materials, exhibit exceptional capacitive energy storage performance in aqueous electrolytes. Current research primarily concentrates on enhancing the electrical conductivity and capacitive performance of CPs via molecular design and structural control. However, the absence of a comprehensive understanding of the impact of molecular chain spatial order on ion/electron transport and capacitive performance impedes the development and optimization of advanced electrode materials. Here, a solvent treatment strategy is employed to modulate the molecular chain spatial order of PEDOT : PSS films. The results of electrochemical performance tests and Grazing Incidence Wide Angle X-ray Scattering (GIWAXS) show that Poly(3,4-ethylenedioxythiophene) : poly(styrenesulfonic acid) (PEDOT : PSS) films with both face-on and edge-on orientations exhibit exceptional electronic conductivity and ion diffusion efficiency, with capacitive performance 1.33 times higher than that of PEDOT : PSS films with only edge-on orientation. Consequently, molecular chain orientations conducive to charge transport not only enhance inter-chain coupling, but also effectively reduce ion transport resistance, enabling efficient capacitive energy storage. This research provides novel insights for the design and development of higher performance CPs-based electrode materials.

Tunable Interfacial Electric Field‐Mediated Cobalt‐Doped FeSe/Fe3Se4 Heterostructure for High‐Efficiency Potassium Storage

AbstractThe interfacial electric field (IEF) in the heterostructure can accelerate electron transport and ion migration, thereby enhancing the electrochemical performance of potassium‐ion batteries (PIBs). Nevertheless, the quantification and modulation of the IEF for high‐efficiency PIB anodes currently remains a blank slate. Herein, we achieve for the first time the quantification and tuning of IEF via amorphous carbon‐coated undifferentiated cobalt‐doped FeSe/Fe3Se4 heterostructure (denoted UN‐CoFe4Se5/C) for efficient potassium storage. Co doping can increase the IEF in FeSe/Fe3Se4, thereby improving the electron transport, promoting the potassium adsorption capacity, and lowering the diffusion barrier. As expected, the IEF magnitude in UN‐CoFe4Se5/C is experimentally quantified as 62.84 mV, which is 3.65 times larger than that of amorphous carbon‐coated FeSe/Fe3Se4 heterostructure (Fe4Se5/C). Benefiting from the strong IEF, UN‐CoFe4Se5/C as a PIB anode exhibits superior rate capability (145.8 mAh g−1 at 10.0 A g−1) and long cycle lifespan (capacity retention of 95.1 % over 3000 cycles at 1.0 A g−1). Furthermore, this undifferentiated doping strategy can universally regulate the IEF magnitude in CoSe2/Co9Se8 and FeS2/Fe7S8 heterostructures. This work can provide fundamental insights into the design of advanced PIB electrodes.

Tunable Interfacial Electric Field-Mediated Cobalt-Doped FeSe/Fe3Se4 Heterostructure for High-Efficiency Potassium Storage.

The interfacial electric field (IEF) in the heterostructure can accelerate electron transport and ion migration, thereby enhancing the electrochemical performance of potassium-ion batteries (PIBs). Nevertheless, the quantification and modulation of the IEF for high-efficiency PIB anodes currently remains a blank slate. Herein, we achieve for the first time the quantification and tuning of IEF via amorphous carbon-coated undifferentiated cobalt-doped FeSe/Fe3Se4 heterostructure (denoted UN-CoFe4Se5/C) for efficient potassium storage. Co doping can increase the IEF in FeSe/Fe3Se4, thereby improving the electron transport, promoting the potassium adsorption capacity, and lowering the diffusion barrier. As expected, the IEF magnitude in UN-CoFe4Se5/C is experimentally quantified as 62.84 mV, which is 3.65 times larger than that of amorphous carbon-coated FeSe/Fe3Se4 heterostructure (Fe4Se5/C). Benefiting from the strong IEF, UN-CoFe4Se5/C as a PIB anode exhibits superior rate capability (145.8 mAh g-1 at 10.0 A g-1) and long cycle lifespan (capacity retention of 95.1 % over 3000 cycles at 1.0 A g-1). Furthermore, this undifferentiated doping strategy can universally regulate the IEF magnitude in CoSe2/Co9Se8 and FeS2/Fe7S8 heterostructures. This work can provide fundamental insights into the design of advanced PIB electrodes.

Design of symmetric supercapacitor based on Co3O4/Carboxymethyl cellulose nanoflakes with excellent cyclic stability

An advanced electrode material having fine micro/nano-architecture that provide unique qualities like ultra-high charge storage capabilities, high specific area and efficient pathway for ion insertion will always have superior position in the energy sphere. The prime motive of the present work is to fabricate carboxymethyl cellulose (CMC) encapsulated cobalt oxide nanoflakes as pioneered electrodes for supercapacitors. Utilizing a Faradaic candidate (cobalt oxide), which traps charges abundantly that leads to attracting capacitance (381 F g−1 at a specific current of 1 A g−1) with least charge transfer resistance (0.87 Ω). Make use of CMC as host that supports the composite via providing admirable cyclic life (100 % capacitance retention even after 5000 continuous charge/discharge cycles). Un-interrupted charge delivery that probably attributed to the formation of flaky architecture of cobalt oxide which was encapsulated by carbon matrix. As the end, a symmetric supercapacitor was designed using Co3O4/C nanoflakes as both positive and negative electrode. The fabricated two cell could capable of maintaining its stability of 95.87 % from its initial value after 5000 cycles of charge and discharge at a practical current density of 20 A g−1. The outcomes of the present study (three and two cell configuration as well) will open new gateways in energy regime for next generation supercapacitors.

Redox behavior in hydrothermally synthesized thistle flower-like Co3O4–NiO-GO composite for advanced supercapacitor electrodes

The advancement in carbon derivatives has significantly boosted the efficacy of recently produced electrodes designed for energy storage applications. Utilizing the hydrothermal technique, conductive single and composite electrodes comprising Co3O4–NiO-GO were synthesized and utilized in supercapacitors within three-electrode systems. The Co3O4–NiO-GO composite electrode demonstrated better rate capability and excellent long-term reliability, as well as a noteworthy energy density at comparatively large power levels. The Co3O4–NiO-GO hybrid electrode had an ideal capacitance of 986.5 F/g at an applied current density of 1 A/g, according to the data. Furthermore, after 5000 cycles, this composite electrode displayed an outstanding cycling stability of 90.4 %. The results indicate that the combined electrode surpasses individual metallic oxide electrodes, with the addition of graphene oxide contributing to the improved performance. When the efficiency of the three samples was evaluated, it was clear that this Co3O4–NiO-GO electrode outperformed the GO/Co3O4 and GO/NiO electrodes. This improvement can be due to the composite electrode's synergistically impact from Co3O4, NiO, and GO.

Shielding unfavorable interaction by oxygen-mediated interlayer chemical bonding enables high-capacity and stable MoS2 cathode

Molybdenum disulfide (MoS2) as cathodes for aqueous zinc-ion batteries (AZIBs) typically undergoes sluggish kinetics and irreversible structure distortion because of the strong interaction between intensely electronegative sulfur and intercalated Zn2+, especially for thick electrodes. Herein, we propose a new oxygen-mediated interlayer chemical bonding strategy to achieve high-performance MoS2 cathode in thick electrode (5–15 mg cm−2). The oxygen-mediated interlayer chemical bonding is facilely formed by intercalating oxygen-rich β-cyclodextrin into MoS2 nanosheets (denoted as MoS2-β-CD), which not only expands the interlayer spacing (from 6.4 to 9.6 Å) but also effectively weakens the electrostatic interaction between Zn2+ and host frameworks, endowing it with fast electron/ion transport and robust structural stability. Consequently, even with 10 mg cm−2 loading, the MoS2-β-CD cathode delivers an impressive specific capacity of 228.0 mA h g−1 (2.3 mA h cm−2) at 4 mA cm−2, superior to most advanced MoS2-based electrodes. Additionally, the MoS2-β-CD electrode also possesses significantly enhanced durability (85.3 % vs. 28.6 % capacity retention after 5000 cycles). This work provides unique inspiration for rational design of AZIB cathodes for practical applications.

Facile sonication synthesis of MnAl2O4/ZnO nanocomposite as an advanced electrode material for supercapacitor applications

Present studies on maintaining, effective energy providers and storage systems have developed because of problems with energy limitations, fossil fuel depletion and pollution. Spinel oxide nanocomposite electrode material is a superior remedy for supercapacitors (SCs). Herein, we synthesized MnAl2O4 and MnAl2O4/ZnO nanocomposites using the sonication method for energy storage devices. The manufactured material’s morphology, interfacial area and structural features were determined using scanning electron microscopy (SEM), Brunauer Teller Emmett analyses (BET) and X-ray diffraction (XRD), respectively. The crystalline nature of MnAl2O4 and MnAl2O4/ZnO nanosheets was observed by the XRD analysis. The electrochemical performance of the manufactured material was determined utilizing nickel foam (NF) as a conductive surface and 2.0 M KOH electrolyte, galvanostatic charging-discharging (GCD), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) study. Electrochemical outcomes showed that MnAl2O4/ZnO nanocomposite exhibits specific capacitance (Cs) of 1490.07 F/g at 1.0 A/g with high cyclic stability over 5000th cycles. Furthermore, an energy and power density of 55.96 Wh/kg and 260 W/Kg, correspondingly, were exhibited by MnAl2O4/ZnO nanocomposite pseudocapacitors. Compared to MnAl2O4 (0.47 Ω) the charge transfer resistance (Rct) value for MnAl2O4/ZnO (0.12 Ω) was smaller calculated via Nyquist plot and exhibited steady behaviour for 50 h. The outstanding potential of the electrode material MnAl2O4/ZnO was highlighted in this work, along with a novel method for producing multi-element composite materials at a reasonable cost and with excellent performance that could find use in a variety of supercapacitor and upcoming energy storage applications.

Addressing the Carbonate Issue: Electrocatalysts for Acidic CO2 Reduction Reaction.

Electrochemical CO2 reduction reaction (CO2RR) powered by renewable energy provides a promising route to CO2 conversion and utilization. However, the widely used neutral/alkaline electrolyte consumes a large amount of CO2 to produce (bi)carbonate byproducts, leading to significant challenges at the device level, thereby impeding the further deployment of this reaction. Conducting CO2RR in acidic electrolytes offers a promising solution to address the "carbonate issue"; however, it presents inherent difficulties due to the competitive hydrogen evolution reaction, necessitating concerted efforts toward advanced catalyst and electrode designs to achieve high selectivity and activity. This review encompasses recent developments of acidic CO2RR, from mechanism elucidation to catalyst design and device engineering. This review begins by discussing the mechanistic understanding of the reaction pathway, laying the foundation for catalyst design in acidic CO2RR. Subsequently, an in-depth analysis of recent advancements in acidic CO2RR catalysts is provided, highlighting heterogeneous catalysts, surface immobilized molecular catalysts, and catalyst surface enhancement. Furthermore, the progress made in device-level applications is summarized, aiming to develop high-performance acidic CO2RR systems. Finally, the existing challenges and future directions in the design of acidic CO2RR catalysts are outlined, emphasizing the need for improved selectivity, activity, stability, and scalability.

An ultrasensitive electrochemical sensor based on boron-doped porous graphene for efficient detection of nitrite in food

Boron (B) doping plays a critical role in adjusting the electronic properties of carbon materials. In this work, B-doped porous graphene (B-PG) was successfully prepared by a simple strategy and used as an advanced electrode material for the detection of nitrite (NO-2) in food. The scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were employed to characterize this B-PG. Due to the ideal doping of boron atoms, the material has good conductivity and exhibits excellent electrochemical catalytic performance. NO-2 was used as the representative analytes to demonstrate the sensing performance of B-PG. It is found that the B-PG modified GCE exhibited a linear response over the concentration range from 3 μM – 3 mM and 3 mM – 15 mM, with a detection limit of 1.1 μM. The designed electrochemical sensor has good analytical performance, such as high sensitivity, good reproducibility and acceptable accuracy, and can be successfully applied to the accurate and precise detection of residual NO-2 in food.

Continuous Lithium‐Ion Extraction From Seawater and Mine Water With a Fuel Cell System and Ceramic Membranes

The demand for electronic devices that utilize lithium is steadily increasing in this rapidly advancing technological world. Obtaining high‐purity lithium in an environmentally friendly way is challenging by using commercialized methods. Herein, we propose the first fuel cell system for continuous lithium‐ion extraction using a lithium superionic conductor membrane and advanced electrode. The fuel cell system for extracting lithium‐ion has demonstrated a twofold increase in the selectivity of Li+/Na+ while producing electricity. Our data show that the fuel cell with a titania‐coated electrode achieves 95% lithium‐ion purity while generating 10.23 Wh of energy per gram of lithium. Our investigation revealed that using atomic layer deposition improved the electrode's uniformity, stability, and electrocatalytic activity. After 2000 cycles determined by cyclic voltammetry, the electrode preserved its stability.