N2 Sorption Analysis Research Articles

PANI/Porous Carbon Palm Kernel Shell via <i>In Situ</i> Polymerization Method for Supercapacitor Electrode

This paper attempts to evaluate the use of composite of polyaniline (PANI)/palm kernel shell-derived porous carbon (C-PKS) as alternative materials for supercapacitor electrodes. The preparation of PANI/C-PKS composites was carried out using an in-situ polymerization method. After the composite was formed, the structures and morphologies were characterized using an N2-sorption analyzer, SEM - EDX, and TGA. As for the performance of supercapacitor electrodes, the composite was tested using a three-electrode system. Structural and morphological characterization results showed that PANI was successfully deposited in C-PKS. The amount of PANI deposited in C-PKS was ca. 7.5%, obtained from TGA analysis. Meanwhile, the capacitance performance test results showed that the PANI/C-PKS composite featured a specific capacitance of ca. 116 F/g. There was an increase in specific capacitance compared to the blank material (C-PKS only) which showed only 94 F/g.

Synthesis, thermal evolution and magnetic investigations of SBA-15 silica functionalized with anchored iron phosphonate molecules.

In the current work, we report on the synthesizing of a series of novel nanocomposite materials obtained by functionalizing the SBA-15 silica matrix with anchored iron phosphonate molecules and the following thermal treatment. The obtained results reveal the formation of a unique amorphic layer of Fe-based compounds on the surface of silica walls of SBA-15 channels as a result of the organic groups' decomposition after moderate thermal treatment. Due to their unique structure, represented in an active Fe-containing amorphous coating spread over a large surface area, these materials are of great interest for their potential applications in fields such as catalysis, adsorption, and non-linear optics. The obtained materials remain amorphous, preserving the SBA-15 mesoporous structure up to temperatures of approximately 800 °C, after which the partial melting of the silica backbone is observed with the simultaneous formation of nanocrystals inside the newly-formed glassy mass. All obtained materials were characterized using such techniques as thermogravimetry, transmission and scanning electron microscopy combined with energy dispersive x-ray spectroscopy mapping, Raman spectroscopy, N2sorption analysis, x-ray diffraction, x-ray photoelectron spectroscopy, Mössbauer spectroscopy, and SQUID measurements.

The catalytic performance of FexMn1-xWO4 as novel wolframite-type nanocatalysts for the selective dehydration of methanol into dimethyl ether

Selective production of dimethyl ether (DME), as a second-generation biofuel, under mild green conditions is still a challenge. Herein, FexMn1-xWO4 wolframite-type materials were proposed for the first time as efficient, selective, and stable catalysts towards methanol dehydration into DME. A simple one-step co-precipitation approach was used to fabricate the nanocomposites, and their catalytic performances were evaluated in comparison to earlier studies and to the commercial γ-Al2O3 in terms of activity. The catalysts’ structure, morphology, and porosity were identified by XRD, XPS, FTIR, TEM, and N2-sorption analyses. Results of XRD and XPS confirmed the successful synthesis of FexMn1-xWO4 catalysts. Acidity of these nanocomposites were greatly influenced with the variation in x-value, calcination temperature, and doping with SO42−. The Brønsted characters of the acid sites and their weak and medium strength were investigated from PY-FTIR, chemisorption of basic probes and pyridine-TPD. The variation of the catalytic activities of these nanocomposites was strongly correlated to the variation in the catalyst acidity. The catalytic activity results indicated that Fe0.5Mn0.5WO4 catalyst calcined at 500 °C and modified with 5 wt.% of SO42- is the most effective nanocomposite with conversion values of 86 and 90% at reaction temperatures of 250 and 275 °C, respectively and all of 100% DME selectivity. The remarkable enhancement in the catalytic activity due to the doping with SO42- is attributed to the inductive effect of S = O group created on the catalyst surface. This nanocomposite could be regenerated many times with nearly the same efficiency and selectivity. Moreover, it offered a long-term stability (∼120 h) towards DME production.

Synthesis of Ketjenblack Decorated Pillared Ni(Fe) Metal-Organic Frameworks as Precursor Electrocatalysts for Enhancing the Oxygen Evolution Reaction.

Metal-organic frameworks (MOFs) have been investigated with regard to the oxygen evolution reaction (OER) due to their structure diversity, high specific surface area, adjustable pore size, and abundant active sites. However, the poor conductivity of most MOFs restricts this application. Herein, through a facile one-step solvothermal method, the Ni-based pillared metal-organic framework [Ni2(BDC)2DABCO] (BDC = 1,4-benzenedicarboxylate, DABCO = 1,4-diazabicyclo[2.2.2]octane), its bimetallic nickel-iron form [Ni(Fe)(BDC)2DABCO], and their modified Ketjenblack (mKB) composites were synthesized and tested toward OER in an alkaline medium (KOH 1 mol L-1). A synergistic effect of the bimetallic nickel-iron MOF and the conductive mKB additive enhanced the catalytic activity of the MOF/mKB composites. All MOF/mKB composite samples (7, 14, 22, and 34 wt.% mKB) indicated much higher OER performances than the MOFs and mKB alone. The Ni-MOF/mKB14 composite (14 wt.% of mKB) demonstrated an overpotential of 294 mV at a current density of 10 mA cm-2 and a Tafel slope of 32 mV dec-1, which is comparable with commercial RuO2, commonly used as a benchmark material for OER. The catalytic performance of Ni(Fe)MOF/mKB14 (0.57 wt.% Fe) was further improved to an overpotential of 279 mV at a current density of 10 mA cm-2. The low Tafel slope of 25 mV dec-1 as well as a low reaction resistance due to the electrochemical impedance spectroscopy (EIS) measurement confirmed the excellent OER performance of the Ni(Fe)MOF/mKB14 composite. For practical applications, the Ni(Fe)MOF/mKB14 electrocatalyst was impregnated into commercial nickel foam (NF), where overpotentials of 247 and 291 mV at current densities of 10 and 50 mA cm-2, respectively, were realized. The activity was maintained for 30 h at the applied current density of 50 mA cm-2. More importantly, this work adds to the fundamental understanding of the in situ transformation of Ni(Fe)DMOF into OER-active α/β-Ni(OH)2, β/γ-NiOOH, and FeOOH with residual porosity inherited from the MOF structure, as seen by powder X-ray diffractometry and N2 sorption analysis. Benefitting from the porosity structure of the MOF precursor, the nickel-iron catalysts outperformed the solely Ni-based catalysts due to their synergistic effects and exhibited superior catalytic activity and long-term stability in OER. In addition, by introducing mKB as a conductive carbon additive in the MOF structure, a homogeneous conductive network was constructed to improve the electronic conductivity of the MOF/mKB composites. The electrocatalytic system consisting of earth-abundant Ni and Fe metals only is attractive for the development of efficient, practical, and economical energy conversion materials for efficient OER activity.

Preparation of Membrane Electrode Assemblies Using Waste Tire Derived Carbon Supported Platinum Catalyst

Carbon supported Pt catalyst materials were synthesized from waste tire derived carbon by two different methods (microwave and refluxing). Catalysts and carbons were physically (XRD, N2 sorption analysis, TGA) and electrochemically characterized (RDE, CV, PEMFC single cell measurements). The RDE measurements were performed in 0.1 M HClO4 solution. For PEMFC single cell measurements, membrane-electrode assembly systems (MEAs) were prepared from catalyst materials by using different methods of coating the cathode layer and additional treatments. Catalysts were sprayed onto the membrane or GDL. In addition, MEAs were prepared where the catalyst was pipetted into GDL in several drops. Some of the MEAs were additionally treated with extra layer of Nafion and hot-pressed. The highest power density (0.42 W cm−2) was achieved with the MEA where the Pt catalyst synthesized via refluxing method was coated on the GDL with multiple drops and additional treatments were applied.

Waste Tire Derived Carbon Support for Non-Platinum-Group Metal Catalyst Materials for Oxygen Reduction Reaction in Alkaline Medium

A porous carbon material was synthesized using waste tire granules via pyrolysis. Six non-platinum-group metal catalyst materials were synthesized based on this carbon material, Fe(NO3)3 · 9H2O, and either dicyandiamide or guanidine carbonate as the nitrogen source. Synthesis parameters such as pyrolysis temperature, precursor mass ratios, and acid washing time were varied for each material. All catalysts were characterized physically using HR-SEM, SEM-EDX, and N2 sorption analyses as well as electrochemically using the rotating disk electrode method in 0.1 M KOH. The materials were rich in nanofibers, and exhibited moderate porosity and specific surface area (S BET = 77-194 m2 g-1). By modifying the synthesis parameters of the materials, the electrochemical properties were successfully improved, achieving E onset = 0.92 V vs RHE and E 1/2 = 0.82 V vs RHE (Fe-guan III 900). The number of transferred electrons in the ORR was n = 4 for the more active materials.

Highly porous activated carbon prepared from the bio-waste of yellow mustard seed for high-capacity supercapacitor applications

Herein, we report the synthesis and electrochemical performance of the porous carbon produced from the bio-waste of the yellow mustard seed plant by the chemical activation process. We have optimized the chemical process to produce mesoporous activated carbon structure with a high specific surface area of 563 m2/g. The N2-sorption analysis confirms the presence of mesoporous structure of the activated carbon. The nanometer scale porosity and chemical composition of the activated carbon was investigated by transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). The crystallinity and defects analyses were conducted using XRD and Raman spectroscopy, revealing the existence of both amorphous and crystalline phases of the porous activated carbon. The electrochemical double-layered capacitor (EDLC) of the activated carbon electrodes was monitored for long-cycling. The galvanostatic charge-discharge (GCD) studies reveal a significantly high-specific capacity of 198 F/g at a current density of 0.25 A/g. In addition, the cyclic voltammetry (CV) measurements deliver a high reversible capacitive behavior and cyclic stability up to 2100 cycles. Furthermore, we observed a low value of equivalent series resistance (ESR) and charge transfer resistance, indicating an excellent electrode/electrolyte interface which can reversibly facilitate the electrolyte ion transport across the electrodes.

Trimetallic Oxide Foam as an Efficient Catalyst for Fixation of CO2 into Oxazolidinone: An Experimental and Theoretical Approach

The excess anthropogenic CO2 depletion via the catalytic approach to produce valuable chemicals is an industrially challenging, demanding, and encouraging strategy for CO2 fixation. Herein, we demonstrate a selective one-pot strategy for CO2 fixation into "oxazolidinone" by employing stable porous trimetallic oxide foam (PTOF) as a new catalyst. The PTOF catalyst was synthesized by a solution combustion method using transition metals Cu, Co, and Ni and systematically characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), N2 sorption, temperature-programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS) analysis. Due to the distinctive synthesis method and unique combination of metal oxides and their percentage, the PTOF catalyst displayed highly interconnected porous channels along with uniformly distributed active sites on its surface. Well ahead, the PTOF catalyst was screened for the fixation of CO2 into oxazolidinone. The screened and optimized reaction parameters revealed that the PTOF catalyst showed highly efficient and selective activity with 100% conversion of aniline along with 96% selectivity and yield toward the oxazolidinone product at mild and solvent-free reaction conditions. The superiority of the catalytic performance could be due to the presence of surface active sites and acid-base cooperative synergistic properties of the mixed metal oxides. A doubly synergistic plausible reaction mechanism was proposed for the oxazolidinone synthesis experimentally with the support of DFT calculations along with bond lengths, bond angles, and binding energies. In addition, stepwise intermediate formations with the free energy profile were also proposed. Also, the PTOF catalyst displayed good tolerance toward substituted aromatic amines and terminal epoxides for the fixation of CO2 into oxazolidinones. Very interestingly, the PTOF catalyst could be significantly reused for up to 15 consecutive cycles with stable activity and retention in physicochemical properties.

MnxWO4 Nanostructure-Based Catalysts for Single-Step Oxidation of Cyclohexane and Methane to Oxygenates

Activation of the C–H bond in cyclohexane (CYH) and methane is a crucial step to obtain desirable oxygenated products using nanostructured catalyst and is a great challenge and an efficient route to mitigate the inauspicious effects of climate change. The active sites were identified using XRD, HR-TEM, SEM, N2 sorption analysis, TPR, Raman, XPS, TGA, in situ DRIFT, XAS, etc. In optimal reaction conditions, 46% of CYH was converted into adipic acid (AA) on MnxWO4 nanostructures within 6 h. The recyclability test confirmed the catalyst heterogeneity, which revealed no appreciable loss of catalytic activity even after three consecutive reactions. In situ DRIFT study reveals that CYH is oxidized to cyclohexanone and cyclohexanol (KA oil) and is further oxidized to AA via carboxylate intermediates. DFT studies disclosed that MnOx species are responsible for the C–H activation of CYH, and the Mn2+/Mn3+ redox centers play a vital role in the absorption of KA oil to form AA. Herein, we demonstrated the significant role of the “MnOx” species and that adequate Lewis and Bronsted acidic sites, redox centers of (Mn2+/Mn3+), and lattice oxygen are accountable for the CYH conversion toward the AA. Additionally, we have reported the oxidation of methane to methanol (146 μmole per gram of catalyst) in the presence of water at 75 °C without over-oxidation products.

Synthesis and characterization of calcium carbonate/carbon from water lettuce via hydrothermal carbonization process

The conversion of biomass into value-added products has recently received much attention for a broad range of applications. In this work, water lettuce was converted into calcium carbonate (CaCO3)/carbon via hydrothermal carbonization (HTC) and pyrolysis at 900 °C. The HTC temperature and time varied in the range of 160–200 °C for 6–18 h, respectively. X-ray diffraction analysis indicated that the samples consisted of a mixture of calcite and vaterite phases of CaCO3 and amorphous carbon. The ratio of calcite and vaterite phases varied with HTC time. The Fourier transform infrared spectroscopy (FTIR) result showed the characteristic absorption bands confirming the presence of CaCO3. Scanning electron microscopy (SEM) images revealed the large crystal of CaCO3 and fine carbon particles. From the N2 sorption analysis, the sample prepared from the HTC at 200 °C for 6 h had the highest specific surface area of 95 m2/g due to the development of micropores. The results presented in this work demonstrated that both HTC temperature and time play critical roles in altering the surface area and phase structure of CaCO3/carbon. The CaCO3/carbon derived from water lettuce can potentially be used and adapted for many applications.

Sol-gel derived porous aluminum oxide cryogel – Fiber composite systems

The main aim of present research was to develop a new low-cost synthesis route to produce ultralight Al2O3 cryogel – fiber composite materials for high temperature insulation. The Al2O3 fibers give the matrix in these composites, instead of the typical reinforcement phase. The synthesis of precursor systems of fiber drawing and freeze drying is based on sol–gel chemistry. The starting materials (inorganic Al salts, organic solvents, and additives) were the same for both type of porous Al2O3 systems. The length of fibers (5–10 cm) is sufficient to form a matrix in the composites. The average diameter of fibers is 10 µm; the size of cryogel particles is generally 20–30 µm in the composites. The composite systems were characterised by 2D and 3D SEM, N2 sorption analysis, FTIR spectroscopy, thermal conductivity measurements, thermo-vacuum, vibration, and satellite tests.

The effects of supported Pd, Pt, Re, Rh, Ru, Ir, Au, and Ni catalysts on renewable hydrocarbon production from alternative feedstock

Screening tests of supported commercial and prepared Pd, Pt, Re, Rh, Ru, Ir, Au (5%), and Ni (5–65%) metal catalysts were conducted under one-pot solvent-free hydrotreating (HT) conditions to evaluate their activity, selectivity, and potential for renewable hydrocarbon (RH) production from rapeseed oil (RO). Catalysts were characterized by XRF, XRD, FE-SEM, TEM, and N2 sorption analysis. Composition of RO, liquid, and gaseous products were analyzed by GC-FID, GC-MS, C, H, N, S elemental analysis, FT-IR, and GC-TCD. Full conversion of RO with RH yield up to 85% were achieved over most active supported commercial Ni (65%) and Re, Rh, Ru (5%) catalysts in short residence time (up to 10 min) under relatively mild reaction temperature 340 °C and initial H2 pressure 10 MPa. Noticeable effect of Ru catalysts on cleavage of -C-C- bond reactions make them promising for practical application in RH synthesis. Multi-function SiO2–Al2O3 supported Ru (5%) catalyst (Ru5SAp) prepared by developed simple method is perspective for wide molecular weight hydrocarbon production by –CC- hydrogenation, oxygen removal and cleavage of -C-C- bonds including ring opening reactions for structure modification of different raw materials – fats, oils, phenols, and fossil based feedstocks. Benzene, toluene, tetralin, guaiacol, and n-nonadecane were used as model compounds for investigation of catalytic effects. Ru5SAp possesses similar performance as most active supported commercial noble metal catalysts in HT process of RO. It is reusable up to three HT reaction cycles although deactivation of catalyst causes significant changes in obtained hydrocarbon composition.

Photocatalytic degradation of methylene blue and rhodamine B using one-pot synthesized nickel oxide grafted glycine (NiO @GLY) nanostructured: Oxygen vacancies effect

A venerable challenge in environmental and materials science is the degradationof organic contaminants from wastewater using visible-light irradiation. The nickel oxide nanocomposite was synthesized using the facile one-pot combustion method at 550 °C. XRD, TEM, and N2 Sorption analysis confirmed the existence of mesoporous textured surfaces. Both spherical and hexagonal nanocrystals were produced with particle sizes ranging from 30 to 56 nm. The hexagonal nanocrystals appeared by increasing the glycine loading. The particle size of as-synthesized NiO @GLY was about 5–16 nm, with spherical morphology. The as-prepared hybrid composites were used to degrade harmful dyes. These produced systems seem to be governed by the interaction involving negatively charged nickel oxide nanoparticles and the amino group of glycine, as evidenced by zeta potential management. The degradation mechanism was found to follow the pseudo-first-order kinetics. S4 shows a promising result with degradation efficiency of 99 % methylene blue, 96 % rhodamine B, and 93 % for the mixed dye. The enhancement is related to oxygen vacancies, which support the photocatalyst's activity and stability.

Surface engineered active Co3+ species in alkali doped Co3O4 spinel catalyst with superior O2 activation for efficient CO oxidation

CO oxidation is one of the most extensively investigated fields of research as it takes prime importance in environmental fortification and is highly challenging to explore efficient heterogeneous catalysts to achieve effectual conversion. In the present work, Co3O4 and alkali metal-doped Co3O4 spinel materials were obtained by the co-precipitation method and employed as suitable catalysts for CO oxidation. The catalysts were prepared by calcining the precipitated hydroxides of Co at 300°C, and 800°C (with and without the presence of water vapor) in the air atmosphere. The synthesized materials were characterized by powder X-ray diffraction, N2-sorption analysis, H2-TPR, SEM, and XPS techniques. Then the catalytic activity of catalysts is evaluated for CO oxidation using molecular O2 as an oxidizing agent. The effect of thermal treatment and also the role of alkali metal in CO oxidation are studied. The promotional effect of alkali (Li, Na, and K) in Co3O4 materials was observed with higher CO conversion, where the influence of Li ions in the Co3O4 catalyst was far greater than in other doped catalysts. Definite characteristics, nature of alkali-doped catalysts, and oxidative influence involved in CO oxidation reaction mechanism were carefully studied. In a general perspective, this work shows the influence of surface properties of alkali ion-doped Co3O4 spinel catalysts that consequently control the reactivity toward CO oxidation.

Low-Cost and Environmental-Friendly Route for Synthesizing Nano-Rod Aluminosilicate MAZ Zeolite.

Preparation of nano-rod aluminosilicate Mazzit (MAZ) zeolite under low-cost and environmental-friendly route is attractive, but still challenging. Herein, we report a green route for synthesizing nano-rod MAZ zeolite (MAZ-N) using low-cost and environmental-friendly choline chloride as template. Various characterizations including powder X-ray diffraction (XRD), scanning electron microscope (SEM), N2 sorption, and thermogravimetry-differential thermal analysis (TG-DTA) show that MAZ-N samples have good crystallinity and uniform porous structures. Furthermore, the crystallization process and impact of synthesis conditions of MAZ-N samples have been investigated in detail. These results suggest the potential applications of MAZ-N zeolites as supporting catalyst compounds in industrial processes.

Towards the Development of Sustainable Hybrid Materials to Achieve High Cr(VI) Removals in a One-Pot Process.

Rising manufacturing costs resulting from the current global situation make it necessary to economize at all stages of production, including waste management. Cost-effective materials that reduce the release of pollutants into the environment are becoming mandatory. In this work, a sodium silicate polymeric material, functionalized with iron, was synthesized. The material contains iron-rich nanostructures on the surface, which are responsible for the decontamination process. The inorganic material was further treated with a reducing eucalyptus extract to improve its decontamination performance. Both the inorganic and hybrid materials were used for decontamination of Cr(VI), a widely emitted chemical waste product. The hybrid material provided the best results (1.7 g Cr(VI)·g-1 Fe) in a one-pot process combining reduction and adsorption. The Langmuir-Freundlich model and a statistical thermodynamics adsorption model, together with removal rates, were used to study the processes. High adsorption energies were found, especially in the adsorption of Fe(II) on the polymeric base (33.2 kJ∙mol-1). All materials were characterized using SEM, EDS and N2 sorption, TGA, and IR analyses. In conclusion, the hybrid material synthesized in this study is cheap and easy to produce through environmentally friendly synthesis, and it is a promising adsorbent for the prevention of pollution issues in effluent discharges.

Ordered mesoporous silica matrices supported ionic liquids for efficient CO2 separation from CO2/CH4 gas mixture: Experimental and theoretical investigation

Global concern over CO2 reduction to avoid global warming has escalated due to alarming CO2 concentrations in the atmosphere. In this connection, supported-ionic liquids (SILs) have been prepared by physically imbibition of 1-ethyl-3-methylimidazolium tetrafluoroborate (C2mim BF4) ionic liquid (IL) into ordered mesoporous silica (MS) matrices to design SILs-membranes (SILMs) for gas separation technology. These SILs were characterized by powder XRD, 29Si NMR, SEM, FTIR, and 1H NMR spectroscopy, N2 sorption, and TGA analyses. FTIR study reveals that vibrational frequencies related to C2mim+ cation ring remain unchanged upon confinement of nanopores of MS whereas Si-O-Si band, Si-O band, and anion band shifted indicating IL interacting with the MS surfaces. Density functional theory (DFT) calculations also explore the structural features of these SILs. SILMs based on Pebax-1657 were also designed using a solution casting technique to evaluate their gas separation performance and characterized using XRD and SEM techniques. C2mimBF4/MCM-48 membrane exhibit higher permeability for CO2 both in single and mixed gas studies. These results were further supported by DFT analysis in terms of complexation energies (Ec) which demonstrates the strong affinity of these SILs membranes towards CO2 and CH4 gases, respectively. Further, a nice correlation was established between the experimental and theoretical findings.

Adsorption kinetics analysis and optimization of Bisphenol A onto magnetic activated carbon with shrimp shell based precursor

Activated carbons synthesized from biomass (agricultural and food wastes) are considered promising materials for adsorbing organic pollutants. In this study, the mixture of shrimp shell (SS) and cellulose (C) were used as precursors for the synthesis of activated carbon (SS@C) with high surface area, well-developed pore structure and stable structure. On this basis, the magnetic adsorption material was prepared through NaHCO3 activation and Fe3O4 precipitation. Mean pore diameter (nm), surface area (m2·g−1), and micropore size (cm3·g−1) of SS@C.AC-M were characterized by SEM-EDS and N2 sorption analyses. The characterization of SS@C.AC-M revealed that the optimal mass ratio of SS@C and NaHCO3 was 1:1.5. In the absorption of Bisphenol A (BPA), the synergistic effects of BPA concentration, pH, and retention time were analyzed by response surface methodology (RSM). A pseudo-second-order model was proposed, which revealed the maximum adsorption capacity of the BPA onto SS@C.AC-M was 207.77 mg g−1. To test the reusability of SS@C.AC-M adsorbent, 5 cycles of pollutant removal experiments were carried out. This work provides a synthesis and optimization method of biomass-based activated carbons for the absorption of organic pollutants in wastewater.

In-Situ Synthesis of Layered Double Hydroxide/Silica Aerogel Composite and Its Thermal Safety Characteristics.

To adjust the thermal safety of hydrophobic silica aerogel, layered double hydroxide (LDH)/silica aerogel (SA) composites were prepared by an in-situ sol-gel process at ambient pressure. This study found the physical combination of SA and MgAl-LDH based on the FTIR spectra and phase composition of LDH/SA. The N2 sorption analysis confirms that the introduction of MgAl-LDH does not change the mesoporous attribution of LDH/SA significantly. With the increase in MgAl-LDH addictive content, the low density (0.12–0.13 g/cm3), low thermal conductivity (24.28–26.38 mW/m/K), and large specific surface area (730.7–903.7 m2g) of LDH/SA are still maintained, which can satisfy the requirements of thermal insulation. The TG-DSC analysis demonstrates that the endothermic effects and metal oxides formed during the MgAl-LDH decomposition are beneficial to the improvement of the thermal stability of LDH/SA composites. In addition, it was found that the gross calorific values of LDH/SA composites decrease with an increase in MgAl-LDH addictive content, all of which are lower than that of the pure SA. The research outcomes indicate that the thermal safety of LDH/SA composites is enhanced significantly by doping MgAl-LDH without impairing too many of the excellent properties, which benefits their expansion in the thermal insulation field.

Synthesis of Polymer-Derived Carbon for Ibuprofen Removal from Simulated Wastewater

Ibuprofen is a nonsteroidal anti-inflammatory drug classified as one of the emerging contaminants from the pharmaceuticals group. Ibuprofen detected in the environment indicates that wastewater treatment facilities have a limited ability to remove this substance. Residual ibuprofen that accumulates continuously can harm ecosystems in the waters and indirectly affect human health. Adsorption using porous material is a method that can reduce the amount of ibuprofen in wastewater. This research synthesized porous carbon by pyrolysis of phenolic polymer. The resulting material was then characterized using an N2-sorption analyzer, SEM, and XRD. After being characterized, the material was used to adsorb ibuprofen at various concentrations. SEM characterization showed that carbon had voids or channels for adsorbing ibuprofen molecules. N2-sorption analyzer delivered that the polymer-derived carbon has a specific surface area of about ​​594 m2 g-1. Based on the adsorption test result, the porous carbon could adsorb the ibuprofen molecules in the simulated wastewater well and followed the Freundlich equilibrium model.