Journal of Porous Materials最新文献

In the present work, a glassy carbon electrode (GCE) was surface modified by a poly (methylene disulfide)/Au–nanoparticles/multiwall carbon nanotubes (PMDS/AuNPs/MWCNT) to improve its ability to detect of trace mercury cations in polluted water. The produced electrode was characterized with FE-SEM, HR-TEM, AFM, XRD, and FT-IR techniques. The obtained results proved the success of the modification process and revealed that the process had a significant effect on the morphology of the electrode and its surface roughness. EIS analysis demonstrated the improvement of the electrochemical properties of the surface-modified sample. Accordingly, the obtained charge transfer resistance (R_ct) decreased from 477.1 Ohm cm² for the unmodified GCE to 83.4 Ohm cm² for the modified-GCE. The designed modified electrode was used as an ultra-sensitive electrode for determining the concentration of Hg²⁺ cation using the differential pulse anodic stripping voltammetry (DPASV) technique.

In the present work, the metal-organic framework MIL-101(Cr) was modified by grafting with piperazine (Pz) in order to enhance the low-temperature CO₂ adsorption characteristics. The effect of piperazine loading was studied by varying the percentage of piperazine (0%, 20%, 50%, and 80%). The adsorbent materials were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), N₂ adsorption-desorption, and thermogravimetric analysis (TGA). The characterization studies confirmed the successful incorporation of piperazine on MIL-101. The CO₂ adsorption kinetics and adsorption isotherms model were investigated at three different temperatures (30 °C, 40 °C, and 50 °C) to better understand the behavior of CO₂ adsorption on the synthesized adsorbents. It was found that 50%pz/MIL-101 can enhance CO₂ capacity up to 67% compared to bare MIL-101. Furthermore, piperazine grafted on MIL-101 can increase the rate constant and improve the binding energy between CO₂ molecules and the surface of adsorbents. The regenerability for CO₂ adsorption of pz/MIL-101 had nearly no drop after eight adsorption-desorption cycles. Thus, the pz/MIL-101 provides an excellent opportunity to capture CO₂ in industrial applications.

Gold (Au) with excellent properties, is widely used in many fields, resulting in the depletion of Au resources and environment pollution due to a great deal of wastewater containing Au(III) produced in the industrial production process. Hence, it is necessary to remove and recover Au from wastewater. In this work, a novel hyperbranched polyethyleneimine functionalized porous polyacrylonitrile/graphene oxide nanofiber membrane (HP-PAN/GO) for adsorption of Au(III) was fabricated by electrospinning, hot-water soak and grafting methods. The effect of the solution pH, initial concentration and contact time on the adsorption performance of HP-PAN/GO for Au(III) was explored by batch experiments. The adsorption process was investigated by pseudo-first-order kinetic, pseudo-second-order kinetic, intra particle diffusion models, Langmuir and Freundlich isotherms. The results showed that the HP-PAN/GO with abundant amino functional groups and pore structure was successfully fabricated. The adsorption and reduction of HP-PAN/GO for Au(III) were simultaneous, and Au(III) adsorbed HP-PAN/GO was partially reduced to elemental Au with hexagonal flakes and irregular particles, and the maximum adsorption capacity of HP-PAN/GO for Au(III) was 2601.27 mg·g⁻¹. The removal rate of the HP-PAN/GO for Au(III) remained over 83% after five adsorption cycles. Moreover, the HP-PAN/GO had excellent adsorption selectivity in coexisting ion system. The HP-PAN/GO could be a promising candidate for effective removal and recovery of Au(III) in wastewater.

This research aims to explore the utilization of Ocimum basilicum leaf extract as a green and sustainable method for the synthesis of Fe₃O₄/NiO nanocomposites (Fe₃O₄/NiO NC) with potential applications in photocatalytic hydrogen evolution and organic dye degradation. The synthesized Fe₃O₄/NiO NC exhibited a unique bandgap energy of 2 eV, making it an effective visible-light photocatalyst. X-ray diffraction and scanning electron microscopy confirmed the successful formation of the cubic crystal structure with an average crystallite size of 25.7 nm. Fourier transform infrared spectroscopy analysis revealed the presence of hydroxyl groups on the NC surface, which contributed to its photocatalytic properties. Under sunlight exposure, the Fe₃O₄/NiO NC demonstrated remarkable photocatalytic degradation efficiency of 99.3% for toluidine blue, 99.0% for 4-bromophenol, and 95.0% for methyl blue within 140 min. The photocatalyst also exhibited excellent reusability with only a slight decrease in efficiency after five cycles. Additionally, the Fe₃O₄/NiO NC displayed high photocatalytic activity in hydrogen evolution, generating 933.9 µmol/g of H₂ over 8 h at a concentration of 0.7 g/L. This green synthesis approach, utilizing Ocimum basilicum extract, provides a cost-effective and eco-friendly method to produce Fe₃O₄/NiO NC with enhanced photocatalytic properties, holding great promise for sustainable energy and water purification applications. The study contributes to the understanding of novel nanocomposites and their potential for addressing urgent environmental challenges, underscoring their scientific value in green chemistry and renewable energy research.

The self-developed magnetic nanoparticles supported octadecane amine-functionalized mesoporous carbon composite was synthesized in this work. A sample pretreatment method for rapid detection of organophosphorus pesticide residues in green leafy vegetables was investigated based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) technology and gas chromatography-mass spectrometry. The surface structure of the magnetic mesoporous composite was characterized by transmission electron microscopy and a magnetometer. The experimental results show that the magnetic mesoporous material can eliminate the matrix interference, improve the detection efficiency and simplify the operation compared with the traditional purification agent. The residues of 16 organophosphorus pesticides in green leafy vegetable matrix have a good linear relationship in the concentration range of 0.02–0.25 µg/mL, and the correlation coefficient (R²) is between 0.9943–0.9997. At the addition levels of 0.02, 0.05 and 0.10 mg/kg, the average recovery rate of 16 organophosphorus pesticides in green leafy vegetable matrix is between 81.3–94.0%, the relative standard deviation is less than 10%, and the minimum detection limit is 0.01–0.08 µg/mL. The results showed that all green leafy vegetables met the maximum residue limit of organophosphorus pesticides. This method has the advantages of high sensitivity, strong universality, high accuracy, good stability, financial and economic. It is suitable for detecting pesticide residues in other vegetables and fruits and sample pretreatment.

A new adeninecarboxamide ligand, N-(9 H-purin-6-yl) pyridine-2-carboxamide (H₂pzac) has been synthesized by a green chemistry method using tetrabutylammunium bromide (TBAB) ionic liquid as an environmentally friendly reaction medium. The H₂pzac ligand was anchored on modified SBA-15-Cl and utilized for detection of Hg²⁺ in aqueous solution. The as-constructed SBA-15@Hpzac sensor shows a high specific surface area as well as pore volume of 250 m²/g and 0.54 cm³/g, respectively. The fluorescence assessment indicated that the designed SBA-15@Hpzac sensor presented highly sensitive and selective behavior to Hg²⁺ ion over different cations including Zn²⁺, Ni²⁺, Co²⁺, Cu²⁺, Mn²⁺, Pb²⁺, Ba²⁺, Mg²⁺, Ca²⁺, Na⁺, Fe³⁺, Fe²⁺, Al³⁺, Cd²⁺ and K⁺. The fluorescence response of the SBA-15@Hpzac sensor for selective detection of Hg²⁺ ion is excellent with detection limit (LOD) of 1.07 × 10^− 6 M. The application of the SBA-15@Hpzac sensor in determination of Hg²⁺ ions in two real water samples was also investigated.

The CO₂ and N₂ sorption performances in neat and mesoporous silica supported ionic liquids were studied at ambient pressure. The prepared ionic liquids were four derivatives of 1-alkyl-3-methylimidazolium nitrates, where the alkyl groups were n-C₆H₁₃, n-C₈H₁₇, n-C₁₀H₂₁ or n-C₁₂H₂₅, respectively. These ionic liquids were immobilized onto porous amorphous silica and high-ordered MCM-41 via wet impregnation–vaporization method. The sorbents were characterized using ¹H NMR, N₂ ad/desorption, thermogravimetric analysis (TGA) and X-ray powder diffraction (XRD) methods. By passing dry CO₂ at 25 °C with 12 mL flow rate through either the neat ionic liquids or ionic liquid-loaded solid supports, [C₆mim][NO₃] and (MCM-41)-[C₁₀mim][NO₃](20) showed the highest sorption capacities, with 2.39 and 2.44 (wt%), respectively. The effects of ionic liquid loading, temperature, inlet gas flow rate, gas humidity and alkyl chain length on the CO₂/N₂ sorption capacities were also evaluated. In contrast to blank solid supports, impregnated solid supported ionic liquids lost their mesoporosity, causing a decrease in CO₂ and N₂ adsorption capacity, but an increase in CO₂/N₂ selectivity. For example, the CO₂/N₂ selectivity in (MCM-41)-[C₆mim][NO₃](20) found to be 5.6, but by increase of the ionic liquid portion in (MCM-41)-[C₆mim][NO₃](50), the CO₂/N₂ selectivity increased to 17.2, proving that the ionic liquid plays a decisive role in selective adsorption of CO₂.

In the last ten years, covalent organic frameworks (COFs) which are crystalline, polymers with greater porosity and surface area, have attracted much research interest. The COF materials are made by covalently bonding organic molecules in a pattern that repeats to create a permeable crystal that is perfect for the sorption and storage of gas. They are expedient in the adsorption of contaminants such as CO₂ due to their appealing qualities including durability, improved reactivity, permanent porosity, and increased surface area. This study is an effort to report topology patterns, pore design, Synthetic Reactions of COFs, different methods for the synthesis of COFs and their applications for CO₂ adsorption. This review further focused on the current literature on the adsorption of CO₂.

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The objective of this work was to prepare and evaluate Ni₃S₄/graphene nanostructures for making high-performance supercapacitor electrodes. A one-pot solvothermal method was developed to prepare the hierarchical nanostructures consisting of Ni₃S₄ nanoflowers on graphene nanosheets. Due to the hierarchical structure of Ni₃S₄ nanoflowers on graphene nanosheets, the resulting electrodes exhibited high supercapacitive performance. Herein, the Ni₃S₄/graphene electrode demonstrated the specific capacitance of 978.4 F g^–1 at the current density of 0.5 A g^–1, the rate capability and long-term cycling stability were also excellent. Moreover, the capacitance contribution of NG-60 can reach 87.9% of the total capacity at 10 mV s⁻¹. The high pseudo-capacitive performance can be attributed to the superior electronic conductivity of graphene nanosheets and the well interconnected tiny pores/channels in the Ni₃S₄ nanoflower arrays. The prepared Ni₃S₄/graphene hierarchical nanostructures may be promising as innovative electrode materials for making high-performance supercapacitors.