Large Specific Surface Area Research Articles

Fabrication of Fe/KB composite as sulfur host for Li-S battery.

Lithium sulfur battery is a novel kind of secondary battery which has high energy density, however its application is greatly affected by the shuttle effect of polysulfides generated in the redox reaction of cathode electrode. Metal active sites are supposed as effective catalysts which can absorb and accelerate the conversion efficiency oflithium polysulfides, thus the shuttle effect will be alleviated. In this work, we conducted a simple way to prepare a metal Fe doped ketjen black to serve as the sulfur host of lithium sulfur battery. Ketjen black has a large specific surface area and rich porous structure, while Fe nanodot is an excellent catalyst for lithium polysulfides. Because of these advantages, the Fe/KB host can effectively confine a large amount of active material and accelerate its, therefore the Fe/KB-S cathode electrode show an excellent electrochemical performance.

Reversible Multi-Mode Optical Modification in Inverse-Opal-Structured WO3: Yb3+, Er3+ Photonic Crystal

Reversible optical regulation has potential applications in optical anti-counterfeiting, storage, and catalysis. Compared to common power materials, the reverse opal structure has a larger specific surface area and an increased contact area for optical regulation, which is expected to achieve higher regulation rates. However, it is difficult to achieve reversible and repeatable regulation of the luminescent properties of photonic crystals, especially with the current research on the structural collapse of photonic crystals. In this work, WO3: Yb3+, Er3+ inverse photonic crystals were prepared by the template approach, and reversible multi-mode optical modification was investigated. Upon heat treatment in a reducing atmosphere or air, the color of the photonic crystals can reversibly change from light yellow to dark green, accompanied by changes in absorption and upconversion of luminescence intensity. The stability and fatigue resistance of this reversible optical modification ability were explored through cyclic experiments, providing potential practical applications for photocatalysis, optical information storage, and electrochromism.

Application of Three-Dimensional Porous Aerogel as Adsorbent for Removal of Textile Dyes from Water

The textile industry is one of the most important industries in the European Union. The main environmental problems of the textile industry are the high water consumption, the generated pollution, the variety of chemicals used and the high energy demand. Recently, adsorbents with a large specific surface area and low weight, such as aerogels, have attracted great interest as promising materials for removing dyes from polluted water. Cellulose aerogels are inexpensive and non-toxic. Langmuir and Freundlich isotherms were chosen as the best method to describe the performance of the adsorbent. In this study, the adsorption efficiency of Congo red, Naphthol green B, Rhodamine B and Methylene blue were determined by using an adsorbent synthesized from paper and cardboard waste. The total organic carbon concentration was chosen as an indicator of the concentration of the dyes in the solutions. The aerogel capsules had 5% cellulose content. It was found that the adsorption capacity of the aerogel in the solutions of Congo red varied from 0.028 mg/g to 14.483 mg/g; in the solutions of Naphthol green B, from 0.013 mg/g to 7.698 mg/g; in the solutions of Rhodamine B, from 0.020 mg/g to 8.768 mg/g; and in the solutions of Methylene blue, from 0.024 mg/g to 13.538 mg/g.

Effect of humic substances on the fraction of heavy metal and microbial response

Contamination of soils by Molybdenum (Mo) has raised increasing concern worldwide. Both fulvic acid (FA) and humic acid (HA) possess numerous positive properties, such as large specific surface areas and microporous structure that facilitates the immobilization of the heavy metal in soils. Despite these characteristics, there have been few studies on the microbiology effects of FA and HA. Therefore, this study aimed to assess the Mo immobilization effects of FA and HA, as well as the associated changes in microbial community in Mo-contaminated soils (with application rates of 0%, 0.5% and 1.0%). The result of the incubation demonstrated a decrease in soil pH (from 8.23 ~ 8.94 to 8.05 ~ 8.77). Importantly, both FA and HA reduced the exchangeable fraction and reducible fraction of Mo in the soil, thereby transforming Mo into a more stable form. Furthermore, the application of FA and HA led to an increase in the relative abundance of Actinobacteriota and Firmicutes, resulting in alterations to the microbial community structure. However, it is worth noting that due to the differing structures and properties of FA and HA, these outcomes were not entirely consistent. In summary, the aging of FA and HA in soil enhanced their capacity to immobilization Mo as a soil amendment. This suggests that they have the potential to serve as effective amendments for the remediation of Mo-contaminated soils.

Mesoporous silica nanoparticles as a drug delivery mechanism.

Research in intelligent drug delivery systems within the field of biomedicine promises to enhance drug efficacy at disease sites and reduce associated side effects. Mesoporous silica nanoparticles (MSNs), characterized by their large specific surface area, appropriate pore size, and excellent biocompatibility, have garnered significant attention as one of the most effective carriers for drug delivery. The hydroxyl groups on their surface are active functional groups, facilitating easy functionalization. The installation of controllable molecular machines on the surface of mesoporous silica to construct nanovalves represents a crucial advancement in developing intelligent drug delivery systems (DDSs) and addressing the issue of premature drug release. In this review, we compile several notable and illustrative examples of MSNs and discuss their varied applications in DDSs. These applications span regulated and progressive drug release mechanisms. MSNs hold the potential to enhance drug solubility, improve drug stability, and mitigate drug toxicity, attributable to their ease of functionalization. Furthermore, intelligent hybrid nanomaterials are being developed, featuring programmable properties that react to a broad spectrum of stimuli, including light, pH, enzymes, and redox triggers, through the use of molecular and supramolecular switches.

Hydrogen bond-modulated copper nanocluster-aggregation-induced enhanced ECL with layered double hydroxides-sensing interface for miRNA-135b detection in colorectal cancer

Herein, we developed a novel electrochemiluminescence (ECL) sensing interface based on Mg/Fe layered double hydroxides nanosheets (LDHs) for miRNA-135b detection in human colorectal cancer tissues. The LDHs nanosheet with large specific surface area and abundant active sites can work as the electrode sensing interface to effectively catalyze the electrochemical reactions. Furthermore, the formation of hydrogen bonds between 4-carboxyphenylboronic acid (CBPA) on the copper nanoclusters (Cu NCs) and fluorine ions limited the intramolecular vibration and accelerated electron transfer, greatly improving the luminescence signal. Due to the catalysis of LDH and the aggregation-induced enhanced electrochemiluminescence (AIECL) effect, the ECL quantum yield of Cu NCs has been significantly amplified. The Mg/Fe LDH-based sensing system for miRNA-135b detection had a linear detection range of 10 fM to 10 μM with a detection limit of 3.5 fM. Finally, the cancer tissue extracted from colorectal cancer patients have been successfully detected. The result indicated that the Mg/Fe LDHs sensing interface provided a new and reliable pathway for ECL analysis performance.

Three‐dimensional electrically conductive–hydrophobic layer for stable Zn metal anodes

AbstractThe interrelated side reactions and dendrites growth severely destabilize the electrode/electrolyte interfaces, resulting in the difficult application of aqueous Zn ion batteries (AZIBs). Hydrophobic protective layer possesses natural inhibition ability for side reactions. However, the conventional protective layer with plane structure is difficult to attain joint regulation of side reaction and Zn nucleation. Herein, a novel three‐dimensional (3D) electrically conductive and hydrophobic (3DECH) interface is elaborated to enable stable Zn anode. The as‐prepared 3DECH interface presents a uniform 3D morphology with hydrophobic property, large specific surface area, abundant zincophilic sites, and excellent electroconductivity. Therefore, the 3DECH interface achieves uniform nucleation and dendrite‐free deposition from synergetic benefits: (1) increased nucleation sites and reduced local current density through the special 3D structure and (2) uniform electric potential distribution and rapid Zn2+ transport due to the electroconductive alloy chemistry, thus coupling the hydrophobic property to obtain a highly reversible Zn anode. Consequently, the modified anode achieves a superior coulombic efficiency of 99.88% over 3500 cycles, and the pouch cells using modified anode and LiMn2O4 (LMO) cathode retain a capacity of 84 mAh g−1 after 700 cycles at a reasonable depth discharge of 36%, without dendrite piercing and “dead Zn.”

N‐Doped Carbon Nanofibers and Carbon Nanotubes‐Encapsulated CoNi Alloy as Highly Active Oxygen Reduction Catalysts for Direct Methanol Fuel Cells

The slow oxygen reduction kinetics of direct methanol fuel cell (DMFCs) are one of the limiting factors affecting its application. Therefore, exploring nonprecious catalysts with high activity and methanol resistance is urgently needed. Herein, zeolitic imidazolate framework‐8 particles are first blended with different proportions of metal salts (Ni as well as Co) and further electrospun to obtain a nanofiber precursor. After pyrolysis treatment, a composite catalyst (CoNi@N‐CNFs) with a highly dispersed CoNi alloy phase supported by porous N‐doped carbon nanofiber and carbon nanotube is prepared. The surface electronic structure can be reasonably adjusted by optimizing the doping ratio of Ni and Co. The CoNi@N‐CNFs shows high oxygen reduction activity and methanol resistance. Half‐wave potential and the onset potential of Co1Ni1@N‐CNFs (Co: Ni mole ratio = 1:1) are 0.79 and 0.87 V. Additionally, Co1Ni1@N‐CNF‐modified DMFC endows a high power density (24.07 mW cm−2), which is close to Pt/C‐based DMFC (27.59 mW cm−2). Rich active sites, large specific surface area, and synergy between CoNi alloy and N configuration of CoNi@N‐CNFs effectively accelerate electron transfer, resulting in the superior catalytic activity. This work provides a new strategy to design effective 1D oxygen reduction reaction catalysts in fuel cells.

A Novel MXene@MOF@Pt NPs-Based Enzyme-Free Electrochemical Sensor for highly Sensitive Detection of Hydrogen Peroxide Released from Living Cells

Abstract Rapid and accurate detection of hydrogen peroxide (H2O2), an important reactive oxygen species (ROS) released from living cells, is of great significance for early diagnosis of tumors. Here, a high sensitive enzyme-free electrochemical sensor for the detection of H2O2 released from living cells was constructed based on MXene@ZIF-8@Pt NPs nanocomposites. Through the characterization of physical and chemical properties, it was observed that Pt NPs with excellent catalytic activity were uniformly supported on MXene@ZIF-8, which exhibited excellent conductivity and large specific surface area. Thanks to the significantly enhanced catalytic activity derived from the successful integration of MXene, ZIF-8 and Pt NPs, under the optimal conditions, the sensing platform based on MXene@ZIF-8@Pt NPs exhibited a wide linear range from 355.4 nM to 21.75 mM, with a limit of detection as low as 120.9 nM, while showing satisfactory reproducibility and selectivity. Furthermore, the developed electrochemical sensor enables real-time monitoring of H2O2 released from living Hela cells under N-formylmethionyl-leucyl-phenylalanine stimulation. Overall, the MXene@ZIF-8@Pt NPs developed in this article will become a promising candidate in monitoring physiological processes.

Preparation of solution blow spinning nanofibers and its application in the food field: a review

Abstract Solution blow spinning is a technology that uses high-pressure gas to prepare spinning solution into nanofibers. It has the advantages of high production efficiency and easy operation, and the prepared nanofibers have a large specific surface area, high porosity, and flexible surface functionalization. Therefore, solution blow spinning has received more and more attention in the food field. This paper first introduces the principle of solution blow spinning, the influence of spinning liquid properties, process parameters, and environmental factors on the spinning process. Secondly, it introduces the materials and ways of applying solution blow-spun nanofibers in the food field, such as bacteriostatic food packaging, slow-release food packaging, and intelligent sensors. Finally, the application of solution blow spinning technology in food is summarized and prospected. This paper provides a reference for further research and application of solution blow spinning in the food field at a later stage.

Heterointerface-Rich Ni3N/WO3 Hierarchical Nanoarrays for Efficient Glycerol Oxidation-Assisted Alkaline Hydrogen Evolution.

Glycerol oxidation-assisted water electrolysis has emerged as a cost-effective way of co-producing green hydrogen and HCOOH. Still, preparing highly selective and stable nickel-based metal electrocatalysts remains a challenge. Herein, heterostructure Ni3N/WO3 nanosheet arrays of bifunctional catalysts with large specific surface areas loaded on nickel foam (denoted as Ni3N/WO3/NF) were synthesized. This catalyst was for glycerol oxidation reaction (GOR) and hydrogen evolution reaction (HER) with excellent catalytic performance, a voltage saving of 267 mV compared to oxygen evolution reaction (OER), and a HER overpotential of 104 mV at 100 mA cm-2. The cell voltage in the assembled GOR//HER hybrid electrolysis system reaches 100 mA cm-2 at 1.50 V, 296 mV lower than the potential required for overall water splitting. This work demonstrates that replacing GOR with OER using a cost-effective and highly active Ni-based bifunctional electrocatalyst can make hybrid water electrolysis an energy-efficient, sustainable, and green strategy for hydrogen production.

Pore Fractal Characteristics between Marine and Marine–Continental Transitional Black Shales: A Case Study of Niutitang Formation and Longtan Formation

Marine shales from the Niutitang Formation and marine–continental transitional shales from the Longtan Formation are two sets of extremely important hydrocarbon source rocks in South China. In order to quantitatively compare the pore complexity characteristics between marine and marine–continental transitional shales, the shale and kerogen of the Niutitang Formation and the Longtan Formation are taken as our research subjects. Based on organic petrology, geochemistry, and low-temperature gas adsorption analyses, the fractal dimension of their pores is calculated by the Frenkel–Halsey–Hill (FHH) and Sierpinski models, and the influences of total organic carbon (TOC), vitrinite reflectance (Ro), and mineral composition on the pore fractals of the shale and kerogen are discussed. Our results show the following: (1) Marine shale predominantly has wedge-shaped and slit pores, while marine–continental transitional shale has inkpot-shaped and slit pores. (2) Cylindrical pores are common in organic matter of both shale types, with marine shale having a greater gas storage space (CRV) from organic matter pores, while marine–continental transitional shale relies more on inorganic pores, especially interlayer clay mineral pores, for gas storage due to their large specific surface area and high adsorption capacity (CRA). (3) The fractal characteristics of marine and marine–continental transitional shale pores are influenced differently. In marine shale, TOC positively correlates with fractal dimensions, while in marine–continental shale, Ro and clay minerals have a stronger influence. Ro is the primary factor affecting organic matter pore complexity. (4) Our two pore fractal models show that the complexity of the shale in the Longtan Formation surpasses that of the shale in the Niutitang Formation, and type I kerogen has more complex organic matter pores than type III, aiding in evaluating pore connectivity and flow effectiveness in shale reservoirs.

Non-Enzymatic Glucose Detection by Fe2O3 Nanorods-Reduced Graphene under Physiological pH

Background: Non-enzymatic detection has become a research hotspot because of its alternativity in solving problems compared to enzymatic biosensors, but most of those sensors require a strong basic pH environment (higher than 10) to active their surface, restricting their use in clinical detection because the pH of body fluid is around 7.4. Furthermore, metal oxide sensors with specific morphologies are reported to have a fast electrocatalytic response. Therefore, Fe2O3 nanocomposites with porous structure are selected for glucose detection research in a physiological pH environment. Objective: The study aimed to assess the potential use of porous reduced graphene oxide-Fe2O3 nanorods in glucose detection in a physiological pH environment. Method: Hydrothermal method was used to prepare porous Fe2O3-rGO NRs (Nanorods) and hollow Fe2O3/C nanoparticles. Cyclic voltammetry and electrochemical impedance spectroscopy were used to evaluate the performance of our materials. Results: Porous-reduced graphene oxide-Fe2O3 nanorods have exhibited better performance than hollow carbon-Fe2O3 core-shell nanoparticles for glucose detection in a physiological pH environment. Conclusion: Non-enzymatic glucose sensing based upon cavity Fe2O3-rGO NRs under a physiological pH environment has been successfully realized, attributing to their high electron mobility and large specific surface area. Furthermore, the results of this work indicate that the glucose sensor prepared here has shown good repeatability and stability, which suggests its potential use in clinical detection.

Mesoporous hollow Fe4[Fe(CN)6)]3 hierarchical nanocrystal architecture for advanced sodium-ion batteries

Prussian blue (PB) has been broadly recognized as promising cathode materials for sodium-ion batteries (SIBs) due to its large interstitial space and robust frame structure, whereas their applications are impeded by unsatisfied long-term cyclability and poor rate capability due to its inherent lattice defects. Herein, we report to fabricate the mesoporous hollow Fe4(Fe(CN)6)3 (one kind of PB) hierarchical nanocrystal architecture by the hydrothermal crystallization and HCl etching of the mesoporous precursor Fe4[Fe(CN)6]3 cubic particles, leading to high crystallinity and large specific surface area. The resultant Fe4[Fe(CN)6]3 cathode for SIBs exhibits a good reversibility and cycling stability with a capacity retention of 75.6 % at 0.5 C after 200 cycles as well as superb rate capability featuring a stable discharge specific capacity of 30.2 mAh g−1 at as high as 10 C, demonstrating the fast kinetics and low polarization of electrochemical reaction, which might be ascribed to the unique architecture and high crystallinity. This offers a new route to designing PB cathode of for SIBs with high rate capabilities.

Direct Affinity Ligand Immobilization onto Bare Iron Oxide Nanoparticles Enables Efficient Magnetic Separation of Antibodies.

Magnetic separation is a promising alternative to chromatography for enhancing the downstream processing (DSP) of monoclonal antibodies (mAbs). However, there is a lack of efficient magnetic particles for successful application. Aiming to fill this gap, we demonstrate the suitability of bare iron oxide nanoparticles (BION) with physical site-directed immobilization of an engineered Protein A affinity ligand (rSpA) as an innovative magnetic material. The rSpA ligand contains a short peptide tag that enables the direct and stable immobilization onto the uncoated BION surface without commonly required laborious particle activation. The resulting BION@rSpA have beneficial characteristics outperforming conventional Protein A-functionalized magnetic particles: a simple, fast, low-cost synthesis, a particle size in the nanometer range with a large effective specific surface area enabling large immunoglobulin G (IgG) binding capacity, and a high magnetophoretic velocity advantageous for fast processing. We further show rapid interactions of IgG with the easily accessible rSpA ligands. The binding of IgG to BION@rSpA is thereby highly selective and not impeded by impurity molecules in perfusion cell culture supernatant. Regarding the subsequent acidic IgG elution from BION@rSpA@IgG, we observed a hampering pH increase caused by the protonation of large iron oxide surfaces after concentrating the particles in 100 mM sodium acetate buffer. However, the pH can be stabilized by adding 50 mM glycine to the elution buffer, resulting in recoveries above 85% even at high particle concentrations. Our work shows that BION@rSpA enable efficient magnetic mAb separation and could help to overcome emerging bottlenecks in DSP.

One-Pot Preparation of Mixed-Mode Reversed-Phase Anion-Exchange Silica Sorbent and its Application in the Detection of Cyclopiazonic Acid in Feeds and Agricultural Products

A novel co-bonded octyl and pyridine silica (OPS) sorbent was prepared and applied for the solid phase extraction (SPE) of cyclopiazonic acid (CPA, a type of mycotoxin) in feed and agricultural products for the first time. A simple mixed-ligand one-pot reaction strategy was employed for OPS sorbent preparation. Nitrogen adsorption–desorption measurements, elemental analysis (EI), thermal gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR) analysis demonstrated the successful immobilization of octyl and quaternary ammonium groups onto the surface of silica gel. The large specific surface area, high-density functional groups, and mixed-mode anion-exchange characteristics of these silica particles made them the ideal material for the efficient extraction of CPA. Additionally, the OPS sorbents displayed excellent batch-to-batch reproducibility, satisfactory reusability, and low cost. The SPE parameters were optimized to explore the ionic and hydrophobic interactions between CPA and the functional groups, and the ultra-high performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UPLC-MS/MS) parameters were optimized to obtain a desirable extraction efficiency and high sensitivity to CPA. Meanwhile, the OPS sorbent presented a satisfactory extraction selectivity and low matrix effect. Under the optimized conditions, our developed CPA detection method was used to determine CPA level in rice, wheat flour, corn flour, peanut, and feed samples, exhibiting a lower detection limit, better linearity, higher sensitivity, and satisfactory extraction recovery rate than previously reported methods. Therefore, our method can be preferentially used as a method for the detection of CPA in agricultural products and feeds.

Developments of photo‐/electro‐catalysis based on covalent organic frameworks: A review

AbstractPhoto‐/electro‐catalysis has the characteristics of low cost, high performance, and zero pollution, which meet the policies on environment and energy. Covalent organic frameworks (COFs), a type of crystalline organic skeleton polymers, have been widely applied and investigated in the area of photo‐/electro‐catalysis owing to their advantages of large specific surface area, regular pore size, excellent stability, flexible structural design, and massive active sites. This article reviews the structural characteristics of COFs and the strategies for strengthening the photo‐/electro‐catalytic activity of COF materials. Subsequently, deep insights were put into the photo‐/electro‐catalysis application of COF materials. In the end, the development prospects and challenges faced by COF materials in photo‐/electro‐catalysis are discussed.

Nanosized Tungsten Powder Synthesized Using the Nitridation–Decomposition Method

A facile, one-step nitridation–decomposition method was developed for the synthesis of nanosized tungsten powder with a high surface area. This approach involved the nitridation of WO3 in NH3 to form mesoporous tungsten nitride (W2N), followed by in situ decomposition of W2N to directly yield single-phase W particles. The phase and morphology evolution during the synthesis were systematically investigated and compared with the carbothermal reduction of WO3. It was revealed that powdered tungsten product with single-phase particles was obtained after nitridation at 800 °C combined with in situ decomposition at 1000 °C, displaying an average particle size of 15 nm and a large specific surface area of 6.52 m2/g. Furthermore, the proposed method avoided the limitations associated with intermediate phase formation and coarsening observed in carbothermal reduction, which resulted in the growth of W particles up to ~4.4 μm in size. This work demonstrates the potential of the nitridation–decomposition approach for the scalable and efficient synthesis of high-quality, fine-grained tungsten powder.

Porous Organic Framework Materials (MOF, COF, and HOF) as the Multifunctional Separator for Rechargeable Lithium Metal Batteries.

The separator is an important component in batteries, with the primary function of separating the positive and negative electrodes and allowing the free passage of ions. Porous organic framework materials have a stable connection structure, large specific surface area, and ordered pores, which are natural places to store electrolytes. And these materials with specific functions can be designed according to the needs of researchers. The performance of porous organic framework-based separators used in rechargeable lithium metal batteries is much better than that of polyethylene/propylene separators. In this paper, thethree most classic organic framework materials (MOF, COF, and HOF) are analyzed and summarized. The applications of MOF, COF, and HOF separators in lithium-sulfur batteries, lithium metal anode, and solid electrolytes are reviewed. Meanwhile, the research progress of these three materials in different fields is discussed based on time. Finally, in the conclusion, the problems encountered by MOF, COF, and HOF in different fields as well as their future research priorities are presented. This review will provide theoretical guidance for the design of porous framework materials with specific functions and further stimulate researchers to conduct research on porous framework materials.

LDH-Based Voltammetric Sensors

Layered double hydroxides (LDHs), also named hydrotalcite-like compounds, are anionic clays with a lamellar structure which have been extensively used in the last two decades as electrode modifiers for the design of electrochemical sensors. These materials can be classified into LDHs containing or not containing redox-active centers. In the former case, a transition metal cation undergoing a reversible redox reaction within a proper potential window is present in the layers, and, therefore, it can act as electron transfer mediator, and electrocatalyze the oxidation of an analyte for which the required overpotential is too high. In the latter case, a negatively charged species acting as a redox mediator can be introduced into the interlayer spaces after exchanging the anion coming from the synthesis, and, again, the material can display electrocatalytic properties. Alternatively, due to the large specific surface area of LDHs, molecules with electroactivity can be adsorbed on their surface. In this review, the most significant electroanalytical applications of LDHs as electrode modifiers for the development of voltammetric sensors are presented, grouping them based on the two types of materials.