Large Surface Research Articles

Hollow microporous organic network fiber membrane for efficient extraction of okadaic acid from marine organisms

Membrane-based micro-solid phase extraction (M-μSPE) has garnered great attention in sample pretreatment, suffering an inherent contradiction between permeability and adsorption capacity. In this study, a pure microporous organic network (TEB-DIB-MON) fiber membrane was prepared by combining electrostatic spinning technology, Sonogashira-Hagihara reaction and template sacrifice method. The prepared TEB-DIB-MON membrane exhibited a large specific surface area with a hollow and porous structure, thereby providing excellent solvent permeability and high adsorption capacity for okadaic acid (OA, an algal toxin). Under the optimized conditions, a sensitive analytical method was established by coupling M-μSPE with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The established method has a low detection limit (0.5 pg mL-1), a wide linear range (1.5-1000 pg mL-1, R ≥ 0.9991), and good reproducibility (RSD ≤ 9.4 %, n = 6), which was then successfully applied for OA detection in marine organisms. Trace amounts of OA (59.3-89.0 pg mL-1) was detected in the oyster and prawn samples. This work demonstrated that the excellent application potential of MON membranes in sample pretreatment, while also presents a novel synthesis strategy for MONs membranes.

Nitrogen-doped hierarchically porous carbon derived from biomass for efficient capture of iodine

Effectively capturing radioactive iodine formed during nuclear energy utilization is crucial for environment protection and human health. Herein, we present a facile and effective strategy to synthesize a nitrogen-doped hierarchically porous carbon from corn stalks for iodine capture in gaseous and liquid environment. The as-prepared carbon material possesses a hierarchically micro/mesopore structure with highly developed mesopores, a large specific surface area (1892.99 m2 g−1), and suitable nitrogen-doping (2.32 at.%). As a result, the carbon material exhibits efficient iodine capture performance, showing a large capture capacity of 3.14 g g−1 at 80 °C for iodine vapor and a fast removal rate of ∼97 % within 5 min for iodine aqueous solution, outperforming most of carbon-based materials for iodine capture reported in literatures. Thermodynamic and kinetic analyses reveal that the adsorption of iodine vapor conforms to the Langmuir model and pseudo-second-order model, respectively. Density functional theory calculation results indicate that the doped-nitrogen heteroatoms strengthen the interaction between iodine molecules and carbon, which can enhance the affinity for iodine molecules by forming a donor–acceptor complex through the donation of lone-pair electrons, thereby facilitating effective capture of iodine. This work develops a biomass-based porous carbon with potential to efficiently capture radioactive iodine.

MOF nanoflowers-based flexible portable NO sensors for human airway inflammation detection

The concentration of nitric oxide (NO) in exhaled breath is linked to respiratory diseases, requiring precise detection. Traditional two-dimensional (2D) carbon-based materials used in chemiresistive gas sensors suffer from high detection limits due to a lack of functional sites, while metal oxide sensors are limited by poor selectivity and high operating temperatures, restricting their development. Recently, metal–organic frameworks (MOFs) have emerged as an effective material for NO monitoring due to their superior selectivity; however, their inherent insulating properties hinder practical use. In this study, we synthesized Ni, Co-MOF-74-Carbon Nanotube (CNT) heterostructured nanoflowers, leveraging their bimetallic active sites and large specific surface area to enhance NO adsorption. This composite material, integrated with breathable nanofibrous membranes through physical deposition, exhibits high selection to NO, achieving a linear response range of 30 to 1000 ppb at room temperature and a limit of detection (LOD) of 18.6 ppb. This sensor can accurately detect NO levels in the exhaled breath of both healthy and diseased individuals, confirming its potential for respiratory disease diagnosis. Additionally, we developed a portable device integrating the Ni, Co-MOF-74-CNT- polyacrylonitrile (PAN) membrane, a microcontroller unit (MCU), and a Bluetooth module for real-time NO detection. The systematic design and successful validation of this portable gas sensor pave the way for future home-based real-time monitoring of airway inflammation.

Revealing the effects of functional group in organic linkers on properties of metal organic frameworks electrode and their performance in supercapacitors

The history of developing supercapacitors with increased performance is inextricably linked to the exploration and design of suitable electrode materials. Metal-organic frameworks (MOFs) have attracted intensive attention for use in high-performance supercapacitors thanks to their large specific surface area, tuneable pore sizes and crystal structure. Understanding the influence of MOF structures and properties on the performance of supercapacitors is critical to enhancing their performance. However, so far researchers have been keen on exploring metal atoms in MOFs and have ignored the effects of organic ligands, especially the functional groups thereon, on supercapacitors. In this work, we have studied the impact of organic linkers’ functional groups on the properties of MOFs and how this influences their performance as supercapacitor electrode materials. We synthesized four MOFs with different functional groups, including hydroxyl, nitride and thiol groups and characterised their physicochemical properties and their performance as supercapacitor electrode materials. Characterisation of the specific surface area shows that the BET area decreases from 980.3 m2 g−1 for the original MOF to 12.2 m2 g−1 when the thiol group is incorporated. Furthermore the –OH, –NH, and −SH functionalities reduced the charge transfer resistance (< 1 Ω) and induced more pseudocapacitance, whereas the –OH group dramatically increased the hydrophilicity of the electrode and rate performance of supercapacitors. Although the MOFs without extra function group showed the highest specific capacitance of 1495F g−1, analysis of the normalized areal specific capacitance only shows 1.5 F m−2. The MOFs with the −SH group showed the highest normalized areal specific capacitance of 26F m−2 as well as stable cycling performance of 80 % retention after 10,000 cycles.

Turning properties of Ni/Al2O3 catalyst to improve catalytic ammonia decomposition for green hydrogen production: pH does matter!

In this study, the influence of solution pH (6.0–12.5) of the cation–anion double hydrolysis (CADH) method in the formation of Ni/Al2O3 catalyst and its catalytic performance for green hydrogen production NH3 decomposition was studied for the first time. The physicochemical properties of the prepared catalysts were systematically characterized by various analysis techniques. The results indicated that pH conditions significantly influenced both the structural properties and catalytic activity of the derived Ni/Al2O3 catalysts. The better catalytic activity for NH3 decomposition over catalysts prepared under high pH conditions (pH ≥ 10.0) is mainly due to the appropriate synergic effect of the interaction between Ni and Al2O3 support, large active Ni surface area, and suitable porosity, particle size, and basicity of the catalyst. The correlation analysis and density functional theory (DFT) calculations confirm that the percentage of surface metallic Ni plays a crucial role in controlling the catalytic activity of Ni/Al2O3 catalysts. The 40Ni/Al2O3 catalyst (Ni = 40 wt%) could achieve over 94.5 % NH3 conversion under the harsh reaction conditions of 600 °C and NH3 WHSV of 54000 mL/gcat./h, and that stably maintained for 200 h without any obvious deactivation. Overall, our work not only highlights the critical role of pH conditions in the CADH solution for cost-effective Ni/Al2O3 catalyst preparation but also proposes a promising strategy for developing a highly active, stable, and Ru-free catalyst for practical hydrogen production via NH3 decomposition.

Determination of seven phenoxy carboxylic acid herbicides in water using dispersive solid phase extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry based on metal-organic framework composite aerogel

Phenoxy carboxylic acid herbicides (PCAs) are difficult to degrade and, thus, pose significant threats to the environment and human health. The limit for 2,4-dichlorophenoxyacetic acid is 30 μg/L in China's standards for drinking water quality, 70 μg/L in the United States' drinking water standards, and 30 μg/L in the World Health Organization's guidelines for drinking water quality. Therefore, the development of an effective detection method for trace PCAs in water is a crucial endeavor. Metal-organic frameworks (MOFs) are novel porous materials that possess advantages such as a large specific surface area, adjustable pore size, and abundant active sites. They exhibit excellent adsorption capability for various compounds. However, the applications of MOFs as adsorbents are limited. For example, the process of isolating powdered MOFs from aqueous solutions is laborious, and microporous MOFs exhibit limited surface affinity, which decreases their mass transfer efficiency in the liquid phase. MOF crystals can be embedded in a substrate to overcome these limitations. Aerogels are obtained by drying hydrogels, which are hydrophilic polymers with a three-dimensional crosslinked network structure. Spongy aerogel materials exhibit unique structural properties such as high porosity, large pore volume, ultralow density, and easy tailorability. When MOFs are combined with an aerogel, their efficient and selective adsorption properties are preserved. In addition, MOF aerogels exhibit a hierarchical porous structure, which enhances the affinity and mass transfer efficiency of the MOF for target molecules. At present, MOF aerogels are primarily prepared by freeze-drying or using supercritical carbon dioxide. These drying processes require significant amounts of energy and time. Hence, the development of greener and more efficient methods to prepare skeleton aerogels is urgently needed. In this study, we prepared an environment-friendly aerogel at ambient temperature and pressure without the use of specialized drying equipment. This ambient-dried MOF composite aerogel was then used for the dispersive solid phase extraction (DSPE) of seven PCAs from environmental water, followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The key parameters affecting the efficiency of DSPE, including the extraction conditions, ratio of MIL-101(Fe)-NH2 to sodium alginate, pH of the aqueous samples, extraction time, ionic strength (salinity), and elution conditions, such as the elution solvent ratio, elution time, and elution volume, were investigated to obtain optimal extraction efficiency. The adsorbent could adsorb the target contaminants within 12 min, and the analytes could be completely desorbed within 30 s by elution with 4 mL of 1.5% (v/v) formic acid in methanol solution. The water samples could be analyzed without pH adjustment. The main adsorption mechanisms were electrostatic interactions and π-π conjugation. Thus, a new method based on MOF aerogels coupled with UHPLC-MS/MS was developed for the determination of the seven PCA residues in water. The calibration curves for the seven PCAs showed good linearity (r2≥0.9986), with limits of detection (LODs) and quantification (LOQs) ranging from 0.30 to 1.52 ng/L and from 1.00 to 5.00 ng/L, respectively. Good intra- and inter-day precision values of 6.5%-17.1% and 7.4%-19.4%, respectively, were achieved under low (8 ng/L), medium (80 ng/L), and high (800 ng/L) spiking levels. The developed method was applied to the detection of PCAs in surface water, seawater, and waste leachate, and the detected mass concentrations ranged from 0.6 to 19.3 ng/L. Spiked recovery experiments were conducted at mass concentrations of 8, 80, and 800 ng/L, and the recoveries ranged from 61.7% to 120.3%. The proposed method demonstrates good sensitivity, precision, and accuracy, and has potential applications in the detection of trace PCAs in environmental water.

Prussian Blue Nanocages as Efficient Radical Scavengers and Photothermal Agents for Reducing amyloid-beta Induced Neurotoxicity

The unusual accumulation of amyloid-beta 1–42 (Aβ42) is an essential pathological feature of Alzheimer’s disease (AD), and development of Aβ42 nanomodulators offers a potentially therapeutic approach to AD. Here, we report facile synthesis of the hollow mesocrystalline Prussian blue nanocages (HMPBs), which serve as versatile Aβ42 modulators. Due to the hollow nanostructures and large specific surface area, they can effectively inhibit Aβ42 aggregation by adsorption. They also exhibit robust near-infrared (NIR) photothermal effect for light-to-heat transition, which promotes the depolymerization of Aβ42 fibers. Besides, they display ROS quenching ability to scavenge hydroxyl radicals (•OH) caused by Aβ42 fibers, alleviate cellular oxidative stress, and improve cell survival. This work provides a new kind of Prussian blue nanomaterial for multimodal Aβ modulation.

3D-Micro-Flower like [formula omitted] Nanoplate Solid Solution: A facile and rapid room-temperature synthesis with excellent photocatalytic decomposition of antibiotics in water

This research addresses the environmental threat posed by residual antibiotics in water and explores the potential of the photocatalytic process as an eco-friendly solution for antibiotic wastewater treatment. Here in, a series of BiOBr1−xClx nanoplate solid solutions with varied Br:Cl molar ratios were synthesized through a simple co-precipitation method. These solid solutions exhibited superior visible-light-driven photocatalytic activity compared to pristine BiOCl and BiOBr. Notably, the BiOBr0.25Cl0.75 sample demonstrated exceptional performance, achieving 89% and 99% degradation efficiency for ciprofloxacin (CIP) and tetracycline hydrochloride (TCH), respectively, within 20minutes under optimum conditions. The outstanding performance is attributed to factors such as a large specific surface area, suitable morphology and band gap, effective separation of photo-generated electron-hole pairs, and the presence of meso-size pores in the structure. Thermodynamic studies confirmed the exothermic and spontaneous nature of the photocatalytic reactions. The proposed degradation pathway of CIP and TCH, along with the photocatalytic mechanism, is elucidated. The solid solution, BiOBr1−xClx, exhibits facile recyclability, robust stability, and excellent adaptability to actual aquatic environments, establishing its potential as a promising eco-friendly photocatalyst for antibiotic pollution control.

High-performance flexible CoFe2O4/N-doped carbon nanofiber composite anode materials for sodium-ion batteries

Graphite is traditionally used as an anode material but is unsuitable for use in sodium-ion batteries because it has a low specific capacity and poor safety characteristics, it is therefore necessary to develop alternative anode materials. Flexible CoFe2O4 nanoparticle/N-doped carbon nanofiber films were prepared by electrospinning and calcination. The advantages of this process included inexpensive starting materials, easy preparation, and suitability for commercialization. The inherent shortcomings of CoFe2O4, such as poor electronic conductivity and large changes in volume, were mitigated via elemental doping and the formation of composites with high-quality carbon materials. Nitrogen-doped carbon nanofibers with large specific surface areas and superior mechanical properties were used as the supporting skeleton of the material. These nanofibers limited the volume expansion of CoFe2O4 throughout the cycling process and increased the ion diffusion velocity in the material. The optimal integration of nanoscale CoFe2O4 particles, which possess a higher theoretical specific capacity, with a nitrogen-doped carbon nanofiber conductive framework featuring a crosslinked three-dimensional structure facilitated the infiltration of the electrolyte into the electrode. This integration reduced the diffusion distance of sodium ions and effectively reduced the volume expansion of the material, as well as damage to the material during the electrochemical reaction. After 200 cycles at a current density of 0.1 A g−1, it provided a high sodium storage capacity of 365.7 mA h g−1. The capacity was maintained at 176.3 mA h g−1 even at a high current density of 2 A g−1. Exhibits good cycle stability.

Spatiotemporal Evolution Analysis of Surface Deformation on the Beihei Highway Based on Multi-Source Remote Sensing Data

Under the interference of climate warming and human engineering activities, the degradation of permafrost causes the frequent occurrence of geological disasters such as uneven foundation settlement and landslides, which brings great challenges to the construction and operational safety of road projects. In this paper, the spatial and temporal evolution of surface deformations along the Beihei Highway was investigated by combining the SBAS-InSAR technique and the surface frost number model after considering the vegetation factor with multi-source remote sensing observation data. After comprehensively considering factors such as climate change, permafrost degradation, anthropogenic disturbance, and vegetation disturbance, the surface uneven settlement and landslide processes were analyzed in conjunction with site surveys and ground data. The results show that the average deformation rate is approximately −16 mm/a over the 22 km section of the study area. The rate of surface deformation on the pavement is related to topography, and the rate of surface subsidence on the pavement is more pronounced in areas with high topographic relief and a sunny aspect. Permafrost along the roads in the study area showed an insignificant degradation trend, and at landslides with large surface deformation, permafrost showed a significant degradation trend. Meteorological monitoring data indicate that the annual minimum mean temperature in the study area is increasing rapidly at a rate of 1.266 °C/10a during the last 40 years. The occurrence of landslides is associated with precipitation and freeze–thaw cycles. There are interactions between permafrost degradation, landslides, and vegetation degradation, and permafrost and vegetation are important influences on uneven surface settlement. Focusing on the spatial and temporal evolution process of surface deformation in the permafrost zone can help to deeply understand the mechanism of climate change impact on road hazards in the permafrost zone.

Efficient hybrid supercapacitor performance enabled by large surface area of 2D mesoporous zinc sulfide nano-sheets synthesized via microwaves

Researchers have shown a significant amount of interest in synthesizing high energy density supercapacitors using a simplest, fast, and low cost technique. The electrochemical performance of supercapacitors can be impacted by the surface area and morphology of electrode materials. A one-step, rapid, and economical microwave-assisted synthesis technique was employed in this study in order to prepare mesoporous nanosheets that are composed of zinc sulfide. The ZnS-based nanosheets possess a large surface area of ∼120 m2g−1 and a mesoporous structure of a pore diameter of <22 nm, which offers numerous electrochemical active sites and it facilitates an excellent super capacitive performance, which is due to its shortened ion/electron diffusion path. The prepared mesoporous nanosheets exhibit a higher specific capacitance of 2282 Fg−1 (1037 C/g) when subjected to a 1 Ag−1 in 2 M KOH aqueous electrolyte with high capability rate. The fabricated device exhibits a high specific capacitance of 252.5 Fg−1 (140 C/g) at 1 Ag−1, which produces a remarkable energy density of about 90 Whkg−1 at 800 Wkg−1 value of power density and an excellent retention of ∼95 % after 10,000 cycles at 6 Ag−1. This study designed an instant, straightforward and low-cost approach to fabricate ZnS nanosheet electrode materials that exhibit excellent performance for supercapacitor applications.

Natural DNA-Derived Ultrafine Ir/Ir2P Hybrid on Porous N, P-Codoped Carbon for pH-Universal Energy-Saving Hydrogen Production Assisted by Electrocatalytic Hydrazine Oxidation

Due to the intrinsic slow kinetics and high potential of the anodic oxygen evolution reaction (OER), hydrazine oxidation reaction (HzOR) with ultralow potential is a viable substitute to combine the cathodic hydrogen evolution reaction (HER) for the energy-saving hydrogen generation. Therefore, it is a compelling demand to explore high-performance electrocatalysts for bifunctional HER and HzOR. Herein, natural DNA was employed to prepare the uniform and ultrafine Ir/Ir2P hybrids loaded on N, P-codoped porous carbon (Ir/PNPC) through a facile “mix-and-pyrolyze” approach. Benefitting from abundant heteroatom doping, large surface area and high degree of graphitization, Ir/PNPC only requires the ultrasmall potentials of -22/-347/-54 mV at 100 mA cm-2 for HER, 46/172/227 mV at 10 mA cm-2 for HzOR, and 167/836/864 mV at 100 mA cm−2 for the constructed two-electrode overall hydrazine splitting (OHzS) in the alkaline, neutral and acidic electrolytes, respectively, all exceeding Pt/C and also showing the remarkable energy-efficient superiority over the conventional water splitting. Furthermore, the OHzS system can be readily driven by the as-prepared direct N2H4/H2O2 fuel cell and commercial solar cell with decent H2 generation rate of 1.245 and 1.392 mmol h-1, respectively. This study provides lights on the preparation of the advanced pH-universal HER and HzOR bifunctional electrocatalysts by natural DNA and is also encouraging for the energy-saving H2 production.

A two-pronged strategy to boost the capacitive deionization performance of nitrogen-doped porous carbon nanofiber membranes

Carbon-based capacitive deionization (CDI) systems are universally subject to the limited desalination capacity, due to the electrosorption characteristics and undesirable pore structures. Herein, a two-pronged strategy is proposed to boost the desalination performance of the electrospun carbon nanofibers (CNFs), where silicalite-1 nanoparticles as the internal porogen create mesopores and macropores, and zeolitic imidazolate framework (ZIF-L) leaves as the external carbon source provide micropores and mesopores. This combination results in the large surface area, well-developed graded pore structure, and increased nitrogen content of the core-shell polyacrylonitrile/silicalite-1@ZIF-L-derived CNFs (defined as PCNFs-SZ) electrode, which delivers a superior specific capacitance of 145.4 F g−1 in a neutral electrolyte. The symmetric CDI cell assembled by the self-supporting PCNFs-SZ membrane electrodes holds a prominent desalination capacity of 37.09 mg g−1 and a rapid salt removal rate of 10.36 mg g−1 min−1 at 1.2 V (initial NaCl concentration: 500 mg L−1), and demonstrates significant potential for real-world applications in the desalination and purification of reclaimed water. Furthermore, theory calculations confirm the enhanced Na+-capture capability of PCNFs-SZ. The present work highlights an effective and viable approach to enhance the desalination performance of carbon-based CDI cells.

Synergetic Interplay of MnNi-MOF Composite with 2D MXene for Improved Supercapacitor Application

The growing demand for high-performance energy storage systems has driven the development of advanced materials to improve supercapacitor efficiency. In this study, MXene-MnNi nanocomposites are synthesized and evaluated for their potential as next-generation supercapacitor electrodes. The MnNi alloy, known for its excellent pseudocapacitive properties, is combined with MXene, a two-dimensional material recognized for its exceptional conductivity, mechanical robustness, and large surface area. The uniform dispersion of MnNi and MXene achieved through a straightforward hydrothermal method, optimizes charge transfer and enhances electrochemical performance. Electrochemical testing demonstrates that the 100 MX-MN nanocomposite exhibits a high specific capacity of 1028 C g-1 at 1 A g-1, along with excellent rate capability and long-term stability, outperforming many conventional materials. This outstanding performance is attributed to the synergistic effects of MnNi’s redox activity and MXene’s high conductivity, which together increase active site availability, accelerate ion diffusion, and maintain structural integrity. Additionally, a hybrid aqueous device is assembled using 100 MX-MN as the positive electrode and activated carbon as the negative electrode. The device delivers a maximum energy density of 87.35 W h kg-1 at a power density of 1.98 kW kg-1 and exhibits excellent capacity retention of 88 % after 10,000 charge-discharge cycles. These findings highlight the potential of MXene-MnNi nanocomposites as advanced materials for supercapacitor applications, offering a promising path for more efficient energy storage solutions in modern electronic devices.

L-Shaped Scapular and Parascapular Combined Flap forReconstruction of a Large Surface Defect After SarcomaResection Using ICG Angiography: A Case Seriesof6 Patients.

Soft tissue sarcomas (STS) pose challenges in management due to large defects following wide resection. Reconstructive options are often limited, especially in patients with large circular defects below the gluteal region. This article addresses the question of how to effectively reconstruct such defects while minimizing donor-site morbidity. We present our experience with using an L-shaped combined scapular and parascapular flap after STS resection, highlighting the novelty of employing indocyanine green (ICG) angiography to ensure optimal blood flow and surgical safety. We retrospectively reviewed patients who underwent STS resection and immediate reconstruction using an L-shaped scapular and parascapular combined flap between October 2022 and April 2024. The feasibility of the procedure was assessed by analyzing the patient demographics, tumor characteristics, defect and flap sizes, operative time, and postoperative outcomes, including donor-site complications and shoulder function. Six patients underwent reconstruction using an L-shaped combined flap with no donor-site complications or significant shoulder dysfunction. The average sizes were 15.7 × 13.7 cm for the defect, 20 × 7 cm for the scapular flap, and 23 × 7.3 cm for the parascapular flap. The average operative time was 7 h and 9 min. The average follow-up period was 10.2 months. Except for one case of partial flap necrosis, all flaps survived completely, highlighting the reliability of the procedure. L-shaped combined scapular and parascapular flaps are promising reconstructive techniques for large surface defects after STS resection with low donor-site morbidity and preservation of shoulder function. The novel application of these flaps for large circular defects below the gluteal region, combined with the use of ICG angiography to ensure flap viability and enhance surgical safety, are key contributions of this study.

Construction of calcium zirconate nanoparticles confined on graphitic carbon nitride: An electrochemical detection of diethofencarb in food samples

A well-known fungicide designated diethofencarb (DFC) is used on crops to eradicate fungal infections and increase agricultural production. However, the National Food Safety Standard has established an overall maximum residual limit of 1 mg/kg for DFC, and excessive usage of this chemical has detrimental effects on the environment in real-time. In this work, an improved electrochemical sensor based on hydrothermally synthesized CaZrO3 is incorporated into a g-C3N4 sheet and developed to quickly and accurately screen DFC, a well-known carbamate fungicide. The electrochemical sensor that was successfully designed demonstrated good conductivity, high ion diffusion parameters, a high electro-active surface area, and a quick electron transport ratio when used for DFC detection. The structure, crystalline accuracy, and purity of the as-prepared CaZrO3@g-C3N4 were examined using various analytical and microscopic techniques. Additionally, the cyclic voltammetry technique examined the electrochemical investigations of the CaZrO3@g-C3N4 modified glassy carbon electrode (GCE). A robust synergistic interaction between the CaZrO3 and g-C3N4 makes large surface areas and improved DFC detection possible. The fabricated sensor exhibits a wide linear range of 0.01–230.04 μM, a low detection limit of 1.8 nM, and excellent stability according to the results of the DPV technique. Remarkably, our proposed sensor has proven to be feasible for real-time analysis and can distinguish DFC-spiked various food samples with a good recovery range.

Adsorptive behavior of Rhodamine B dye over hierarchical N-doped carbons from hexamine-based complexes: Equilibrium and kinetics

Pollution from water-soluble dyes is a common issue due to high toxicity and diffiulty in degradation, and its effectively removal is critical for human health and sustainability. In this work, N-doped hierarchical carbons were derived by facile pyrolysis of Co-including hexamine-based complex using glucose as a cross-linker, showing high removal ability using Rhodamine B (RhB) as a model dye. Porous architecture and N-coordination can be easily altered by pyrolysis temperature, where the GNC-900 sample obtained at 900 °C exhibits the best removal ability even outperforming several classical carbons under equal conditions, owing to synergistic effects from large surface areas, high ratio of pyrrolic-N, enhanced interaction between RhB molecules and pore walls, and possible Co-Nx active sites. Adsorptive behaviour is better fitted by pseudo-second-order kinetic model, and the maximum RhB capacity over GNC-900 determined by Langmuir model is highly up to 400.1 mg/g, following mechanisms of pore filling, π-π conjugation, electrostatic, surface complexation and H-bonding. Thermodynamics indicate that RhB removal is exothermic and spontaneous process. Moreover, GNC-900 can be readily regenerated using ethanol and reused at least six times without notable loss in capacity. This novel method facilitates synthesis of N-doped carbons from metal-based complexes, exhibiting high efficiency as adsorbents for water remediation.

Thiourea-linked covalent triazine frameworks enable efficient and selective gold recovery from e-waste leachate

The surging electronic waste (e-waste) has been stimulating the unremitting exploration about the advanced gold recycling technology, which is of great significance to alleviate the shortage of metal resources and minimize the negative environmental impact. Herein, the thiourea-linked covalent triazine frameworks (denoted as PbTu-CTFs) have been designed and constructed by the nucleophilic substitution between cyanuric chloride (CC) and 1,4-phenylene bis(thiourea) (named PbTu) for gold recovery from the actual e-waste leachate. Benefiting from the unique structural characteristics, including large surface areas, abundant porosity, excellent chemical stability, and high-density S, N coordinative sites, the fabricated PbTu-CTFs afford ultrahigh gold adsorption capacity up to 2255 mg/g and fast kinetics, as reflected by 99 % of Au recovery efficiency within 5 min. Meanwhile, satisfactory recyclability and regeneration are maintained after six rounds of consecutive adsorption/desorption tests. Furthermore, the resulting adsorbent is well competent for highly efficient and selective gold recovery from the acidic leaching solution of wasted central processing unit (CPU), exemplify its promising actual application potential.

Enhanced catalytic performance of ethyl-levulinate to γ-valerolactone: Effect of copper loading on Ni/KIT-5 catalyst

A facile wet impregnation method was employed to prepare a bimetallic Ni–Cu catalyst on a mesoporous KIT-5 support, keeping the nickel loading constant (5 wt%) while varying the copper wt.% (xCu, where x = 8, 10, 12, 14). Several physico-chemical techniques, including X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), temperature-programmed desorption of ammonia (NH3-TPD), temperature-programmed reduction of hydrogen (H2-TPR), and X-ray photoelectron spectroscopy (XPS), were utilized for catalyst characterization. An environmentally friendly NiCu bimetallic-supported catalyst system was developed in response to many problems, including metal leaching, sintering, and cost. A mesoporous KIT-5 silica support with a large surface area was used. The hydrogenation of ethyl levulinate to gamma-valerolactone was studied utilizing a high-pressure stirred reactor and a range of reaction temperatures (120–160 °C), hydrogen pressures (10–30 bar), and reaction periods. Various catalysts were used in the investigation. Among all tested catalysts, the 12Cu–5Ni/KIT-5 one shows excellent activity. The best GVL yield is 84% at a conversion of 100% after 8 h of treatment at 150 °C and 25 bar H2 pressure; the promotion is also 76.1%. Optimization of reaction conditions was shown to correlate the physicochemical parameters of the catalyst with its activity.

Heterostructure of perovskite coupled graphitic carbon nitride for enhanced photodegradation under visible light

This study aimed to prepare and characterize LaFeO3 nanoparticles loaded graphitic carbon nitride (LFO/g-C3N4) photocatalyst and investigate the degradation of organic pollutants under UV and natural sunlight exposure. It is observed that LFO nanoparticles of an average size of about 67 nm were distributed on g-C3N4 sheets through chemical bonding owing to the formation of a composite. Compared to LFO and g-C3N4, composite has a good absorption ability to harvest more UV and visible light due to its large surface area and pore size. The photocatalytic studies revealed that the g-C3N4/LFO composite exhibits higher catalytic efficiency and stability for methylene blue (MB) degradation under UV and visible light. Under UV irradiation, the degradation efficiency of LFO, g-C3N4, and g-C3N4/LFO composite in synthetic wastewater was found to be around 50, 80 and 93 % with corresponding rate constants 0.05, 0.02, and 0.1 min−1 in 30 min, respectively. Under natural sunlight, the composite degraded 97 % of MB in 180 min with a rate constant of 0.016 min1. The higher photocatalytic activity of the composite was attributed to the interfacial charge transfer between LaFeO3 and g-C3N4, which are responsible for effective charge separation in the composite. Further, it has been investigated that singlet oxygen species (1O2) and hydroxyl radicals (•OH) are the main reactive species that contributed considerably to the complete degradation of MB. The nanocomposite was also demonstrated to be a stable catalyst and can be reused without any further modification.