High Surface Porosity Research Articles

Decolorization of Congo Red and Reactive Black 5 Dyes with Horseradish Peroxidase-Immobilized Cross-Linked Polymeric Microbeads

In this study, the efficiency of poly(ethylene glycol dimethacrylate-N-methacryloyl-amido-l-tryptophan methyl ester) [PEDMT] microbeads (in the diameter range of 106–180 µm) as a support material for HRP immobilization was evaluated and the immobilized-HRP enzyme was used for decolorization of Congo Red (CR) and Reactive Black 5 (RB5) dyes. The specific surface area of the PEDMT microbeads was 1103 m2 g−1, which is very high. The PEDMT microbeads had a pore volume and pore size of 1.94 cm3 g−1 and 9.99–55.3 Å, respectively. The chemical compositions of the PEDMT and PEDMT–HRP microbead surfaces were analyzed using X-ray photoelectron spectroscopy (XPS). Immobilization yield, activity yield, and immobilization efficiency were 84.9 ± 2.1, 73.8 ± 5.9%, and 86.9 ± 6.9%, respectively. Optimum pH (6.0), temperature (45 °C and 50 °C for free and immobilized enzyme), H2O2 concentration (3% v/v) were investigated in detail. Thermal and storage stability was increased after immobilization and immobilized enzyme preserved more than 55% of its initial activity even after 10 consecutive uses. Decolorization studies were also performed by investigating the effects of pH, CR, and RB5 concentration, enzyme amount, H2O2 concentration, contact time on decolorization efficiency. The decolorization efficiency for CR and RB5 by PEDMT–HRP was 98.20% and 47.99% after 30 min at pH 6.0 and 45 °C. The immobilized-HRP retained 89% and 27% of its initial activity after three repeated cycles with CR and RB5, respectively. The PEDMT microbeads with high surface area, porosity, durability, and reusability exactly met the requirements for HRP immobilization and dye decolorization.

Triboelectric Energy Harvesting from Highly Conjugated Fused Aromatic Ladder Structure Under Extreme Environmental Conditions.

Practical application of triboelectric nanogenerators (TENGs) has been challenging, particularly, under harsh environmental conditions. This work proposes a novel 3D-fused aromatic ladder (FAL) structure as a tribo-positive material for TENGs, to address these challenges. The 3D-FAL offers a unique materials engineering platform for tailored properties, such as high specific surface area and porosity, good thermal and mechanical stability, and tunable electronic properties. The fabricated 3D-FAL-based TENG reaches a maximum peak power density of 451.2 µW cm-2 at 5 Hz frequency. More importantly, the 3D-FAL-based TENG maintains stable output performance under harsh operating environments, over wide temperature (-45-100°C) and humidity ranges (8.3-96.7% RH), representing the development of novel FAL for sustainable energy generation under challenging environmental conditions. Furthermore, the 3D-FAL-based TENG proves to be a promising device for a speed monitoring system engaging reconstruction in virtual reality in a snowy environment.

Polymer-Based Metal-Organic Framework Composite Beads: Optimization for Methyl Orange Adsorption

Metal-Organic Frameworks (MOFs) have gained traction as an adsorbent due to their high surface area and porosity. MIL-101(Fe), a MOF that has been used for removing dyes in water by adsorption, faces the problem of being inseparable from water after use. To get around this difficulty, MIL-101(Fe) was incorporated into composite beads consisting of polymers Chitosan (CS), and Polyvinyl Alcohol (PVA) crosslinked with Glutaraldehyde (GLA) to remove Methyl Orange (MO) from water. The resulting CS/MIL-101(Fe)/PVA beads were optimized based on the right combination of synthesis parameters that gave the highest percent MO removal. It was found that the maximum MO removal can be achieved by beads made of 1500 ppm MIL-101(Fe), 2.0 % PVA, crosslinked in 2.5% GLA. Using FTIR analysis and SEM imaging, the beads exhibited favorable properties for adsorption, as shown by their coarse and porous structure. The beads proved viable for adsorption, exhibiting a percent MO removal of 69.62% upon validation.

The Potential of Electrospinning to Enable the Realization of Energy-Autonomous Wearable Sensing Systems.

The market for wearable electronic devices is experiencing significant growth and increasing potential for the future. Researchers worldwide are actively working to improve these devices, particularly in developing wearable electronics with balanced functionality and wearability for commercialization. Electrospinning, a technology that creates nano/microfiber-based membranes with high surface area, porosity, and favorable mechanical properties for human in vitro and in vivo applications using a broad range of materials, is proving to be a promising approach. Wearable electronic devices can use mechanical, thermal, evaporative and solar energy harvesting technologies to generate power for future energy needs, providing more options than traditional sources. This review offers a comprehensive analysis of how electrospinning technology can be used in energy-autonomous wearable wireless sensing systems. It provides an overview of the electrospinning technology, fundamental mechanisms, and applications in energy scavenging, human physiological signal sensing, energy storage, and antenna for data transmission. The review discusses combining wearable electronic technology and textile engineering to create superior wearable devices and increase future collaboration opportunities. Additionally, the challenges related to conducting appropriate testing for market-ready products using these devices are also discussed.

In-situ grown nickel iron bimetal organic frameworks from activated Ni foam for efficient energy storage and electrocatalysis: Study of metal ratio and nickel precursor effects

Ex-situ fabrication of electroactive electrodes encounters serious peeling off problems. Nickel foam (NF) shows promise as conductive substrate of electroactive electrodes due to high surface area, porosity and conductivity. To broaden NF applications and enhance attachments, applying in-situ growth for establishing efficient active materials on NF is necessary. In this study, nickel iron bimetal organic frameworks (NiFeMOF) are firstly synthesized from activated NF as electroactive electrodes for energy storage and electrocatalysis. Metal ratio and nickel precursor effects are studied to elucidate growing mechanism of electroactive materials. The optimal NiFeMOF/NF presents the highest specific capacitance (CF) of 2017.9 F/g at 20 mV/s, while MOF/NF electrodes prepared with only Ni and Fe respectively show smaller CF values of 622.1 and 1121.8 F/g. The superior electrocatalytic ability is achieved by NiFeMOF/NF. Inclusion of additional Ni salts is necessary for synthesizing Ni-MOF on NF with improved energy storage ability, but that prepared without addition of Ni salt exhibits better electrocatalytic ability. Trade-off between electrochemical surface area and electrical conductivity is proved as crucial factor in designing electroactive materials for energy storage and electrocatalytic water splitting. This study brings novel insights into establishment of effective electroactive materials for electrochemical systems using simple concepts and techniques.

Synthesis Methods, Properties, and Modifications of Biochar-Based Materials for Wastewater Treatment: A Review

The global impact of water and soil contamination has become a serious issue that affects the world and all living beings. In this sense, multiple treatment alternatives have been developed at different scales to improve quality. Among them, biochar has become a suitable alternative for environmental remediation due to its high efficiency and low cost, and the raw material used for its production comes from residual biomass. A biochar is a carbonaceous material with interesting physicochemical properties (e.g., high surface area, porosity, and functional surface groups), which can be prepared by different synthesis methods using agricultural wastes (branches of banana rachis, cocoa shells, cane bagasse, among others) as feedstock. This state-of-the-art review is based on a general description of biochar for environmental remediation. Biochar’s production, synthesis, and multiple uses have also been analyzed. In addition, this work shows some alternatives used to improve the biochar properties and thus its efficiency for several applications, like removing heavy metals, oil, dyes, and other toxic pollutants. Physical and chemical modifications, precursors, dopants, and promoting agents (e.g., Fe and N species) have been discussed. Finally, the primary uses of biochar and the corresponding mechanism to improve water and soil quality (via adsorption, heterogeneous photocatalysis, and advanced oxidation processes) have been described, both at laboratory and medium and large scales. Considering all the advantages, synthesis methods, and applications, biochar is a promising alternative with a high potential to mitigate environmental problems by improving water and soil quality, reducing greenhouse gas emissions, and promoting the circular economy through residual biomass, generating value-added products for several uses.

Tough polycyclooctene nanoporous membranes from etchable block copolymers.

Porous materials with pore dimensions of the nanometer length scale are useful as nanoporous membranes. ABA triblock copolymers are convenient precursors to such nanoporous materials if the end blocks are easily degradable (e.g., polylactide or PLA), leaving nanoporous polymeric membranes (NPMs) if in thin film form. The membrane properties are dependent on midblock monomer structure, triblock copolymer composition, overall molar mass, and polymer processing conditions. Polycyclooctene (PCOE) NPMs were prepared using this method, with tunable pore sizes on the order of tens of nanometers. Solvent casting was shown to eliminate film defects and allowed achievement of superior mechanical properties over melt processing techniques, and PCOE NPMs were found to be very tough, a major advance over previously reported NPMs. Oxygen plasma etching was used to remove the surface skin layer to obtain membranes with higher surface porosity, membrane hydrophilicity, and flux of both air and water. This is a straightforward method to reliably produce highly tough NPMs with high levels of porosity and hydrophilic surface properties.

Applications of different adsorbent materials for the removal of organic and inorganic contaminants from water and wastewater – A review

Increasing wastewater production is posing a threat to the safety and cleanliness of the water. Adsorbents have been used in various industries to remove contaminants from wastewater. In this review, naturally occurring and laboratory–synthesized adsorbents, their past and recent advancements, and future wastewater treatment strategies are comprehensively described. Nanomaterials (NMs) have been extensively used as adsorbents due to their high surface area, porosity, low density, and chemical stability. For effective implementation, the adsorption capacity of NMs is optimized. Compared to larger counterparts, nanomaterials have been found to have higher adsorption rate constants, making them more effective adsorbents. The adverse effects associated with the synthesis and application of these adsorbents are discussed. This review also addresses some significant issues concerning these adsorbents, which could impact future research and practical applications of nano adsorbents for water safety.

Binder-free ultrathin pellets of nanocomposites based on Fe3O4@nitrogen-doped reduced graphene oxide aerogel for electromagnetic interference shielding

The synergistic effects of a hybrid nanocomposite (Fe3O4@NrGO) and their influence on electromagnetic pollution shielding (EMI SE) were explored. This is a current concern where the impacts need to be fully clarified and assertively addressed. Thus, the main focus of the paper was based on the physical and mechanical properties of porosity, surface area, flexibility and, mainly, electrical conductivity of the graphene aerogels, which do not require the use of a binder and are of great interest for the EMI SE area. The precursors (rGO, NrGO and Fe3O4), as well as the nanocomposite, underwent thorough structural characterisation to understand their nature. Characteristic bands of C-N/C=N bonds and a content of 8.03 at% N were identified, with a high N:O ratio of 1.31, indicating efficient doping of the conductive matrix. The aerogel NrGO phase, with a quality of just 5 layers, and the Fe3O4 phase, with domains around 5 nm, were confirmed, as well as the superposition of the signals in the Fe3O4@NrGO pattern. Electron microscopy images and elemental map also demonstrated the efficient distribution of Fe3O4 in the matrix and its porous appearance. Thus, leveraging the advantages of aerogel, extremely light ultra-thin pellets measuring 0.1 mm and weighing 10 mg were produced. The high nitrogen doping of the graphene network, the presence of magnetic nanoparticles, as well as the high surface area and porosity achieved in the production of the nanocomposite, were responsible for high specific shielding effectiveness of 2730 dB · cm−1 at 10.7 GHz and an average in the X-band of 1590 dB · cm−1. Thus, the improved and synergistic mechanisms highlighted the promising advantages of using these highly porous doped materials, demonstrating that the Fe3O4@NrGO hybrid presents high value for investigations in the application of EMI SE.

Schwarzite-based 3D-printed carriers for enhanced performance of sequencing batch biofilm reactor (SBBR) for wastewater treatment

The energy-efficient, green, and sustainable wastewater treatment using biofilm reactors is gaining a lot of attention. The efficiency of biofilm-based reactors (e.g., sequencing batch biofilm reactor (SBBR) and moving bed biofilm reactor (MBBR), etc.) can be further improved with the help of strong, highly active, and functionally engineered carriers. Here, Schwarzite-based 3D-printed biocarriers were prepared to obtain optimum mechanical properties and enhanced organics and nutrient removal efficiencies. The optimized carrier (L2) possesses the highest porosity (∼75%) and specific modulus of resilience and lowest bulk density among the other prepared structures (i.e., L1, L3, and L4). High porosity and specific surface area of the carriers promote enhanced growth of biomass with a total of 0.3 g biomass/carrier. The optimized biocarrier showed ∼95% chemical oxygen demand and ∼84% ammonium nitrogen removal efficiencies, which were attributed to its high specific surface area and porosity. The performance of SBBR with 3D-printed biofilm carriers having only a 15% fill ratio was compared and found better than the conventional K2 carriers used with a filling ratio of 50%. The high mechanical stability and specific surface area of the L2 biocarrier make it feasible to be used as a biofilm carrier, which may drastically reduce the number of carriers thereby directly reducing the cost.

Efficient adsorption removal of 2,4-dichlorophenoxyacetic acid using amine-functionalized metal–organic frameworks (MOFs): Performance and mechanisms

2,4-dichlorophenoxyacetic acid (2,4-D) is a widely used herbicide and plant growth regulator worldwide; however, its overdose and improper use would cause severe eco-toxicological effects on aquatic life, plants, and human life. This work synthesized high-quality MIL-101(Cr)-NH2 nanoparticles via a one-pot hydrothermal reaction and used it in pioneer as an amine-functionalized mesoporous metal–organic frameworks (MOFs) adsorbent for 2,4-D removal. The adsorption kinetics results confirmed that MIL-101(Cr)-NH2 obeys the pseud-second-order kinetic model, and the isotherm results imply that it shows multilayer adsorption following the Freundlich model. Compared to state-of-the-art benchmark MOF adsorbent UiO-66-NH2, MIL-101(Cr)-NH2 achieved a superior 2,4-D adsorption capacity of 348.5 mg/g at pH = 7 with a nearly 50 % increase in adsorption removal rate under ambient conditions. Spectroscopy analysis and density functional theory (DFT) calculations revealed that the distinct large pore size, high surface area and porosity of MIL-101(Cr)-NH2 are the essential physical factors for enhancing the diffusion ability of 2,4-D in the framework. Meanwhile, the electrostatic interactions of the metal clusters and aminated benzene ring with the dissociated 2,4-D anion are the dictated binding forces during adsorption. This mechanism was further validated by the adsorption behaviors of other contaminants over the two MOF adsorbents. Furthermore, the MIL-101(Cr)-NH2 nanoparticles can be chemically anchored onto chitosan to form MIL-101(Cr)-NH2/Chitosan foams with feasible recovery ability and it was found that the MIL-101(Cr)-NH2/Chitosan (1/3) foam showed a comparable 2,4-D removal rate to UiO-66-NH2 (52.2 % vs. 57.7 %). This study reported a high-performance aminated MOF adsorbent for 2,4-D removal and the revealed adsorption mechanisms offer an excellent platform for rational design of advanced adsorbents for acidic contaminants adsorption.

Hierarchical Mn3O4/NiSe2-MnSe2: A Versatile Electrode Material for High-Performance All-Solid-State Hybrid Pseudocapacitors with Supreme Working Durability.

As highly efficient electrochemical energy storage devices are in indispensable demand for numerous modern-day technologies, herein sluggish precipitation followed by an anion exchange procedure has been developed to synthesize an oxide-selenide mixed phase (Mn3O4/NiSe2-MnSe2) novel electrode material with high surface area and porosity for high-performance all-solid-state hybrid pseudocapacitors (ASSHPC). Mn3O4/NiSe2-MnSe2 shows a rich Tyndall effect (in H2O) and possesses randomly arranged low-dimensional crystallites of nearly similar size and uniform shape. The electrochemical analyses of Mn3O4/NiSe2-MnSe2 corroborate good electrochemical reversibility during charge transfer, superior pseudocapacitive charge-storage efficiency, and very low charge transfer and series resistance, ion-diffusion resistance, and relaxation time, which endorse the quick pseudocapacitive response of the material. The Mn3O4/NiSe2-MnSe2||N-rGO ASSHPC device demonstrates excellent charge-storage physiognomies suggestive of rich electrochemical and electromicrostructural compatibility between the electrode materials in the fabricated assembly. The Mn3O4/NiSe2-MnSe2||N-rGO ASSHPC device delivers high mass and area specific capacitance/capacity, very low charge-transfer resistance (∼0.74 Ω), total series resistance (∼0.76 Ω), diffusion resistance, and a relaxation time constant, which endorse the quick pseudocapacitive response of the device. The device delivers higher energy and power density (∼34 W h kg-1 at ∼2994 W kg-1), rate efficiency (∼17 W h kg-1 at ∼11,995 W kg-1), and cyclic performance (∼97.2% specific capacity/capacitance retention after 9500 continuous GCD cycles). The superior Ragone and cyclic efficiencies of the ASSHPC device are ascribed to the multiple redox-active Ni and Mn ions which lead to the supplemented number of redox reactions; "electroactive-ion buffering pool"-like physiognomics of Mn3O4/NiSe2-MnSe2, which facilitate the electrolyte ion dissemination to the electroactive sites even at high rate redox condition; and ideal electro-microstructural compatibility between the electrode materials, which leads to assisted charge transfer and absolute ion dissemination during the charge-storage process.

A deep-insight into the relation between structure of graphene oxide-based interfacial catalyst and fuel oil desulfurization performance in Pickering emulsion

Based on the high stability, easy demulsification and formed large interphase contact area of the Pickering emulsion, its corresponding catalytic oxidative desulfurization (CODS) system has exhibited satisfactory desulfurization results and recycling performance. However, the relation between the interfacial catalyst structure and desulfurization performance in Pickering emulsion systems has rarely been reported. Herein, a stable Pickering emulsion CODS system was established using H3PW12O40 (HPW)-supported graphene oxide (GO) as an interfacial catalyst. Some important structural parameters, including catalyst size, surface porosities and wettability, were adjusted, and their effect on desulfurization performance was analysed in detail. Additionally, the reaction conditions, selectivity and recyclability of the studied system were systematically evaluated. The small catalyst size and high surface porosities could facilitate mass reaction transfer to improve desulfurization performance, but the effect of wettability was most prominent. The Pickering emulsion formed by the amphiphilic catalyst exhibited the optimum distribution state of emulsion droplets with an enlarged interphase contact area. After the optimized design of the catalyst structure, ultradeep fuel oil desulfurization was achieved under mild conditions without stirring. This work provides a useful reference to further mine the mechanism behind the improvement of desulfurization performance in Pickering emulsion systems.

Preparation of novel and recyclable chitosan-alumina nanocomposite as superabsorbent to remove diazinon and tetracycline contaminants from aqueous solution

This work presents a novel, strong and efficient adsorbent (CS@TDI@EDTA@γ-AlO(OH)) prepared through the green process using three components, chitosan, BNPs and EDTA using amide and ester bridges. An eco-friendly and easy approach was used for the preparation of this novel adsorbent, the low cost, easy access to the used materials, and the simplicity of the preparation method are some of the interesting advantages of this work. Also, this prepared adsorbent was used as an adsorbent to remove diazinon organophosphate poison and tetracycline antibiotic from aqueous solutions. In order to confirm the prepared adsorbent structure, the CS@TDI@EDTA@γ-AlO(OH) composite was investigated by various analyses including FT-IR, EDX, XRD, FESEM and TGA. The adsorption behavior of the adsorbent prepared for the removal of tetracycline and diazinon was investigated under different conditions by varying the concentration, temperature, the adsorbent dose, pH and contact time. Based on various tests, the highest diazinon adsorption capacity was obtained for 0.12 g/L adsorbent at pH 7 and 60 °C with 40 mg/L initial concentration. Also, the maximum adsorption capacity of the tetracycline was obtained for 0.12 g/L adsorbent at pH 9 and 60 °C with 30 mg/L initial concentration. The equilibrium results for diazinon and for tetracycline were in good accordance with the Langmuir and Freundlich isotherm models, respectively. Also, the highest adsorption capacities for diazinon at pH 7 and tetracycline at pH 9 were 1428.5 and 555.5 mg/g, respectively. Also the kinetic investigations revealed that the correlation factor (R2) of pseudo-second-order model obtained for the adsorption of diazinon and tetracycline was 0.9986 and 0.9988, while the coefficient k (g/mg.min) was 0.000084 and 0.0033, respectively. These results indicate that the adsorption of diazinon and tetracycline is pseudo-second-order kinetics model. Formation of hydrogen bonds between adsorbate and adsorbent as well as the high specific surface area and porosity of the adsorbent are the main mechanisms that contribute to the adsorption process. In addition, thermodynamic studies indicated that the adsorption of diazinon and tetracycline is a spontaneous endothermic process. The adsorbent prepared in this work was expected to have wide range of applications in wastewater treatment thanks to its good reusability in water and strong removal of diazinon and tetracycline compared to other adsorbents.

Recent Advances in Laser-Induced Graphene-Based Materials for Energy Storage and Conversion.

Laser-induced graphene (LIG) is a porous carbon nanomaterial that can be produced by irradiation of CO2 laser directly on the polymer substrate under ambient conditions. LIG has many merits over conventional graphene, such as simple and fast synthesis, tunable structure and composition, high surface area and porosity, excellent electrical and thermal conductivity, and good flexibility and stability. These properties make LIG a promising material for energy applications, such as supercapacitors, batteries, fuel cells, and solar cells. In this review, we highlight the recent advances of LIG in energy materials, covering the fabrication methods, performance enhancement strategies, and device integration of LIG-based electrodes and devices in the area of hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, zinc-air batteries, and supercapacitors. This comprehensive review examines the potential of LIG for future sustainable and efficient energy material development, highlighting its versatility and multifunctionality in energy conversion.

Composite poly(ethylene oxide)-based solid electrolyte with consecutive and fast ion transport channels constructed by upper-dimensional MIL-53(Al) nanofibers

Novel structural designs for metal organic frameworks (MOFs) are expected to improve ion-transport behavior in composite solid electrolytes. Herein, upper-dimensional MIL-53(Al) nanofibers (MNFs, MIL-53 belongs to the MIL (Material Institute Lavoisier) group) with flower-like nanoflake structures have been designed and constructed via modified hydrothermal coordination. The optimized MNFs with high surface area and porosity can form abundant interfaces with poly(ethylene oxide) (PEO) matrix. The plasticization of MNFs to the PEO matrix will facilitate segmental movement of PEO chains to facilitate Li+ conduction. The unsaturated open metal centers of MNFs can effectively capture bis(trifluoromethanesulfonyl)imide anions (TFSI−) to deliver more free lithium ions for transfer. Moreover, the upper-dimensional nanofiber structure endows lithium ions with a long-range and consecutive transport pathway. The obtained composite solid electrolyte (MNFs@PEO) presents a high ionic conductivity of 4.1 × 10−4 S cm−1 and a great Li+ transference number of 0.4 at 60 °C. The electrolyte also exhibits a stable Li plating/stripping behavior over 1000 h at 0.1 mA cm−1 with inhibited Li dendrite growth. Furthermore, the Li/LiFePO4 and Li/LiNi0.8Mn0.1Co0.1O2 batteries with MNFs@PEO as electrolytes both display great cycling stabilities with high-capacity retention, indicating their potential applications in lithium metal batteries. The study will put forward new inspirations for designing advanced MOF-based composite solid electrolytes.

Comparison of machine learning approaches for the identification of top-performing materials for hydrogen storage

Unique properties of Metal-Organic Frameworks (MOFs), such as their extremely high surface areas and porosity, render them as one of, if not the most promising adsorbents for gas storage applications. However, their extremely flexible and tunable nature has resulted in an enormous expansion of the available material pool which in turn begs the question as to whether an efficient identification of the best materials is feasible. In the last years, Machine Learning (ML) techniques have been extensively applied for the exploration of large material databases, since they can significantly accelerate this process. In this work, “traditional” ML models and models based on our recently developed iterative self-consistent approach are compared with respect to their ability to efficiently identify the best materials of a database. As a case study, we have used hydrogen adsorption in MOFs at different thermodynamic conditions. Despite their high accuracy, traditional models struggle to pinpoint the best materials, regarding usable gravimetric uptake, without compromising computational resources. On the other hand, self-consistent models can even reduce by two orders of magnitude the amount of reference data required for the identification of the best gravimetric materials compared to traditional ones. Notably, 300 training samples are enough for the SC models to correctly identify the top-100 gravimetric materials of a database. Nevertheless, both type of models underperform when they are queried for the top-performing materials with regards to usable volumetric uptake.

Synthesis and structure of anhydrous Zn2EDTA metal-organic framework

Metal-organic frameworks (MOFs) have gained significant attention in materials science due to their unique properties such as high surface area, porosity, and tunable electrochemical characteristics. Among various MOFs, Zn-EDTA compounds have shown potential for electrochemical applications. This paper presents the accident discovery and investigation of a new anhydrous Zn2(EDTA) MOF and its electrochemical performance as an electrode material for aqueous sodium-ion batteries. The study systematically explores the influence of pH and stoichiometric ratio on the formation of Zn2(EDTA) and Zn2(EDTA)(H2O) MOFs using X-ray diffraction analysis. The single-phase anhydrous Zn2(EDTA) compound is synthesized, offering advantages over the hydrated form regarding stability and electrochemical activity. Zn2(EDTA) structure is characterized, revealing a 3D network of channels suitable for interstitial ionic mobility. Thermogravimetric analysis (TGA) is used to study the thermal behavior of Zn2(EDTA), showing two weight loss steps attributed to water and carbon dioxide elimination during decomposition. Electrochemical measurements using cyclic voltammetry in alkaline and neutral electrolytes demonstrate the electrochemical activity of Zn2(EDTA) as an anode material for aqueous sodium-ion batteries. The results suggest that the electrochemical process in both electrolytes involves the reversible stripping/deposition of zinc ions. The anhydrous Zn2(EDTA) MOF exhibits higher peak current intensities and more positive potentials than the hydrated form. The study provides valuable insights for synthesizing and controlling Zn2(EDTA) MOF formation, opening the prospects for searching for new structures in considered-to-be-studied phase regions.

Evaluation of Nanostructured NiS2 Thin Films from a Single-Source Precursor for Flexible Memristive Devices.

Herein, we report the first demonstration of a single-step, in situ growth of NiS2 nanostructures from a single-source precursor onto a flexible substrate as a versatile platform for an effective nonvolatile memristor. The low temperature, solution-processed deposition of NiS2 thin films exhibits a wide band gap range, spherical-flower-like morphology with high surface area and porosity, and negligible surface roughness. Moreover, the fabricated Au/NiS2/ITO/PET memristor device reveals reproducible bipolar resistive switching (RS) at low operational voltages under both flat and bending conditions. The flexible device shows stable RS behavior for multiple cycles with a good memory window (∼102) and data retention of up to 104 s. The switching of a device between a high-resistance state and a low-resistance state is attributed to the filamentary conduction based on sulfur ion migration and sulfur vacancies and plays a key role in the outstanding memristive performance of the device. Consequently, this work provides a simple, scalable, solution-processed route to fabricate a flexible device with potential applications in next-generation neuromorphic computing and wearable electronics.

Mitigation of arsenic and fluoride from water via porous polymeric network knitted with zirconium moiety in three-dimensional shape: Experimental and mathematical modeling investigation

The presence of toxic contaminants in water seriously threatens human health. Thus, in order to address the water pollution through toxic contaminants, a new type of cross-linked porous polymeric microsphere namely; poly(Zirconyl dimethacrylate) (pZrDMA), was successfully prepared by a single-step facile approach. The pZrDMA comprises an acrylate chain of zirconium moiety, which is a proficient adsorbent for arsenic and fluoride remediation. A series of pZrDMA were prepared by varying the relative amounts of reactants to get an appropriate composition. The pZrDMA having, a high surface area (SA: 392.12 m2 g−1) and porosity (Pore size: 0.93–2.36 µm), has exhibited maximum adsorption capacities (qe) of 4.26 mg g−1, 4.22 mg g−1 and 198.5 mg g−1 As(V), As(III) and F− respectively. The pZrDMA displayed high removal efficiency (>97 %) for all the ions over a wide pH range (2.0 ± 0.2 to 10 ± 0.2). The adsorption kinetic and isotherms are well described by the pseudo-second-order model (PSO), and Langmuir isotherm model for both toxic ions arsenic and fluoride. The multicomponent adsorption isotherm with arsenic and fluoride has also studied. The experimental data analysis using the ANN model provides a high accuracy of the model with larger correlation coefficient values (R > 0.99). The pore diffusion modeling predicted the breakthrough time of 174 h, 1542 h, and 1466 h for F−, As(V), and As (III), respectively.