Gas Sorption Analysis Research Articles

Correlating the structure of quinone-functionalized carbons with electrochemical CO2 capture performance

Electrochemical carbon dioxide capture is emerging as an energy-efficient alternative to traditional carbon capture technology. In particular, redox-active molecules that can capture carbon dioxide when electrochemically reduced and release carbon dioxide when electrochemically re-oxidized are under active development. To prepare a carbon capture device, these molecules can be incorporated into a solid electrode in a battery-like cell. In this work, we explore the scope of a recently developed method where anthraquinones are covalently attached to porous carbon supports to obtain electrodes for electrochemical carbon dioxide capture. We functionalize four different porous carbon materials with varying porosities and surface chemistries, and use gas sorption analysis and solid-state NMR spectroscopy to probe the location of the grafted anthraquinones. All four functionalized materials show electrochemically mediated capture and release of carbon dioxide, and we explore the factors that determine their performance. While the anthraquinone-functionalized mesoporous carbon, f-CMK-3, showed the highest quinone loading, it showed poor quinone utilization for CO2 capture and poor long-term cycling stability. In contrast, the predominantly microporous functionalized carbon, f-YP-80F, showed a higher quinone utilization and improved cycling stability. This work can guide the design of functionalized carbon electrodes for electrochemical carbon dioxide capture.

The Role of The Ni/HZSM-5 Ratio on The Anisole Hydrodeoxygenation Reaction

ABSTRACT. Bio-oil is a renewable energy source with high oxygen levels, and anisole is a chemical widely employed in research to represent it. Catalytic hydrodeoxygenation (HDO) reduces the oxygen content. A catalyst known as nickel-modified HZSM-5 has shown promising results for HDO. Meanwhile, catalyst efficiency depends on the Ni/HZSM-5 ratio. So, this study aims to determine how the Ni/HZSM-5 ratio influences the catalyst's properties, activity, and selectivity in anisole HDO. The Ni/HZSM-5 catalyst was made using the wet impregnation method with various ratios of Ni/HZSM-5. The catalysts were analyzed for their morphology using scanning electron microscopy-energy-dispersive X-ray (SEM-EDX). The diffraction patterns were studied using X-ray diffraction (XRD). Surface area and porosity were determined through gas sorption analysis (GSA). Then, the acidity strength was evaluated via temperature-programmed ammonia desorption (NH3-TPD). The characterization results show Ni was successfully impregnated and distributed evenly in HZSM-5 without changing the primary structure. Adding Ni metal to HZSM-5 increases the surface area of the catalyst but reduces its acid strength. The catalytic performance of the catalysts was then evaluated in a flow reactor at 400 °C, using 15 mL/min H2 gas. The liquid products of the reaction were analyzed using gas chromatography-mass spectroscopy (GC-MS). The results of the catalytic performance show that Ni4.5/HZSM-5 has the highest catalytic activity in anisole conversion. At the same time, Ni6.4/HZSM-5 shows the highest selectivity towards benzene-toluene-xylene (BTX). Keywords: Hydrodeoxygenation, nickel, anisole, heterogeneous catalyst, acidity.

Optimizing methane plasma pyrolysis for instant hydrogen and high-quality carbon production

The European Green Deal has set a target for Europe to achieve net-zero greenhouse gas emissions by 2050, necessitating a transition to more sustainable energy sources. Hydrogen gas (H2) has emerged as a promising solution, with methane pyrolysis presenting a viable method for its production. This study explores the optimization of methane plasma pyrolysis for hydrogen and high-quality carbon production. Employing a statistical approach by a design of experiment software, critical process parameters are systematically analyzed to predict their impact within a defined range. Additionally, the paper conducts comprehensive characterization of the solid carbon produced during pyrolysis using imaging, spectroscopic and elemental analysis, and gas sorption analysis methods. The experimental investigation was conducted using a thermal plasma reactor with several settings of influential parameters including methane gas (CH4) content in the plasma gas, electric current, and arc length. The DC-transferred plasma arc is formed using a variable gas mixture of argon gas (Ar) and CH4, with a constant flow rate of 5 Nl/min. Thirteen tests were designed, evaluating responses such as power input, process stability, and H2 yield. The H2 yield indicates the hydrogen produced from CH4, with 100% representing total conversion. While the process exhibited inconstancy, attributed to reactor design constraints, a high H2 yield of 67%–100% was achieved. The results indicate that a higher CH4 content in the plasma gas and extended arc lengths disturb the plasma arc, hence reducing the H2 yield. Increased power input, achieved through higher amperage levels, and a wider reaction zone eased by extending the arc length both led to an improved H2 yield. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) revealed microstructural differences, with carbon samples from the filter exhibiting finer textures and carbon samples from the reactor larger sizes and dendritic particles. Raman spectroscopy confirmed crystalline graphitic-like structures with low defect concentrations, a finding supported by X-ray diffraction (XRD) analysis. Inductively coupled plasma mass spectroscopy (ICP-MS) analysis confirmed high-purity carbon with slight impurities from initial filter contamination. Brunauer-Emmett-Teller (BET) specific surface area calculations based on gas sorption analysis showed significant variations, with filter-collected samples exhibiting 40–170 m2/g and reactor-collected ones showing 7–30 m2/g.

Multi-stage batch adsorption of acephate onto cauliflower like Fe3O4-MMT: Characterization and statistical optimization using response surface methodology

Globally acephate (an organophosphate pesticide) contaminates water bodies, and detriment to the biota is cancer-causing and neurotoxic which needs to be safely removed. This study presents the synthesis and characterization of magnetic montmorillonite (Fe3O4-MMT) as an adsorbent for the adsorption of acephate. The features and characteristics of the nanocomposite were traced by XRD, SEM-EDX, gas sorption analysis, FTIR, and XRF. RSM techniques were used to identify the optimal process variables that result in the highest removal. The numerical optimization of optimum variables corresponds to an initial acephate concentration of 2 mg/L, pH 6 and material adsorbent dose of 0.5 g/L. The uptake of acephate achieved 83.18 % under optimum environs. Dual factors i.e., concentration and dosage remarked as vital parameters that affected the response from ANOVA. Results revealed that equilibrium adsorption data were best fitted with Langmuir and kinetic data were well described by pseudo-first order kinetic model. Thermodynamic parameters such as enthalpy, entropy and Gibb’s energy were evaluated and the effect of temperature on acephate adsorption was studied. Greater acephate adsorption onto on Fe3O4 serves as an excellent material for pesticide mitigation.

The Roles of Impurities and Surface Area on Thermal Stability and Oxidation Resistance of BN Nanoplatelets.

This study considers the influence of purity and surface area on the thermal and oxidation properties of hexagonal boron nitride (h-BN) nanoplatelets, which represent crucial factors in high-temperature oxidizing environments. Three h-BN nanoplatelet-based materials, synthesized with different purity levels and surface areas (~3, ~56, and ~140 m2/g), were compared, including a commercial BN reference. All materials were systematically analyzed by various characterization techniques, including gas pycnometry, scanning electron microscopy, X-ray diffraction, Fourier-transform infrared radiation, X-ray photoelectron spectroscopy, gas sorption analysis, and thermal gravimetric analysis coupled with differential scanning calorimetry. Results indicated that the thermal stability and oxidation resistance of the synthesized materials were improved by up to ~13.5% (or by 120 °C) with an increase in purity. Furthermore, the reference material with its high purity and low surface area (~4 m2/g) showed superior performance, which was attributed to the minimized reactive sites for oxygen diffusion due to lower surface area availability and fewer possible defects, highlighting the critical roles of both sample purity and accessible surface area in h-BN thermo-oxidative stability. These findings highlight the importance of focusing on purity and surface area control in developing BN-based nanomaterials, offering a path to enhance their performance in extreme thermal and oxidative conditions.

Plasma-Treated Cobalt-Doped Nanoporous Graphene for Advanced Electrochemical Applications

Metal–carbon nanocomposites are identified as key contenders for enhancing water splitting through the oxygen evolution reaction and boosting supercapacitor energy storage capacitances. This study utilizes plasma treatment to transform natural graphite into nanoporous few-layer graphene, followed by additional milling and plasma steps to synthesize a cobalt–graphene nanocomposite. Comprehensive structural characterization was conducted using scanning and transmission electron microscopy, X-ray diffraction, Raman spectroscopy, gas sorption analysis and X-ray photoelectron spectroscopy. Electrochemical evaluations further assessed the materials’ oxygen evolution reaction and supercapacitor performance. Although the specific surface area of the nanoporous carbon decreases from 780 to 480 m2/g in the transition to the resulting nanocomposite, it maintains its nanoporous structure and delivers a competitive electrochemical performance, as evidenced by an overpotential of 290 mV and a Tafel slope of 110 mV/dec. This demonstrates the efficacy of plasma treatment in the surface functionalization of carbon-based materials, highlighting its potential for large-scale chemical-free application due to its environmental friendliness and scalability, paving the way toward future applications.

Production of Biodiesel from Candlenut Seed Oil (Aleurites Moluccana Wild) Using a NaOH/CaO/Ca Catalyst with Microwave Heating

Oil fuels derived from fossils are non-renewable, so over time, they will run out and have a negative impact on air pollution. To overcome this, there is a need for environmentally friendly alternative fuels from renewable sources such as biodiesel. This research used microwave heating with a CaO catalyst. NaOH-impregnated snail shells and active carbon support. This research aims to determine the effect of power on the conversion of candlenut seed oil into biodiesel using the NaOH/CaO/CA catalyst both in terms of compliance with the SNI 7182-2015 standard and analysis using GC-MS (Gas Chromatography-Mass Spectrometry). The synthesis of the NaOH/CaO/CA catalyst was carried out through wet impregnation and calcination at a temperature of 500°C and analyzed using gas sorption analysis (GSA). Then proceed to the transesterification process, where the power for microwave heating was varied to 300, 450, and 600 watts with a mole ratio of esterified oil and methanol, namely 1:10 for 3 minutes. The analysis results of the NaOH/CaO/CA catalyst using the GSA instrument have a surface area of 9.306 m2/g, pore volume of 0.033 cc/g, and pore diameter of 14.043 nm. Meanwhile, the results of the biodiesel analysis showed that the optimum biodiesel yield was 85.625% at 600 watts of power and had a kinematic density and viscosity that met the SNI 7182-2015 biodiesel standards. Analysis of biodiesel characteristics using GC-MS showed that the three most optimum biodiesel components were hexadecanoic acid, methyl ester (22.664%), 9,12-Octadedecadienoic acid (Z,Z)-, methyl ester (30.176%) and 9-Octadecenoic acid (Z)-, methyl ester (38.656%).

Short-Time Magnetron Sputtering for the Development of Carbon-Palladium Nanocomposites.

In recent nanomaterials research, combining nanoporous carbons with metallic nanoparticles, like palladium (Pd), has emerged as a focus due to their potential in energy, environmental and biomedical fields. This study presents a novel approach for synthesizing Pd-decorated carbons using magnetron sputter deposition. This method allows for the functionalization of nanoporous carbon surfaces with Pd nano-sized islands, creating metal-carbon nanocomposites through brief deposition times of up to 15 s. The present research utilized direct current magnetron sputtering to deposit Pd islands on a flexible activated carbon cloth substrate. The surface chemistry, microstructure, morphology and pore structure were analyzed using a variety of material characterization techniques, including X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy, gas sorption analysis and scanning electron microscopy. The results showed Pd islands of varying sizes distributed across the cloth's carbon fibers, achieving high-purity surface modifications without the use of chemicals. The synthesis method preserves the nanoporous structure of the carbon cloth substrate while adding functional Pd islands, which could be potentially useful in emerging fields like hydrogen storage, fuel cells and biosensors. This approach demonstrates the possibility of creating high-quality metal-carbon composites using a simple, clean and economical method, expanding the possibilities for future nanomaterial-based applications.

Unveiling the influence of MTMS:TEOS ratios in silica layer membranes enhanced by cetyltrimethylammonium bromide

Silica-based thin-layer membranes, meticulously coated on alumina tubes, were synthesized from methyltrimethoxysilane (MTMS) and tetraethylorthosilicate (TEOS), which were further modified with cetyltrimethylammonium bromide (CTAB) and subsequently deployed for the brine desalination. Comprehensive characterization of the membrane materials was conducted employing Fourier Transform Infrared (FTIR) spectrophotometry, Gas Sorption Analysis (GSA), Thermogravimetric Analysis combined with Differential Scanning Calorimetry (TGA-DSC), Scanning Electron Microscopy (SEM), and an optical tensiometer. A detailed investigation was executed on the effects of varying MTMS:TEOS mole ratios, 10:90 (STL-1), 25:75 (STL-2), 50:50 (STL-3), 75:25 (STL-4), and 90:10 (STL-5), elucidating their impact on the structural attributes and functionalities of silica. These parameters were subsequently correlated with their respective desalination efficacies. The FTIR analysis underscored an evident association between the escalation in cyclic siloxane and methyl groups vis-à-vis increasing MTMS concentrations. An elevated MTMS content conferred the silica matrix with diminished porosity, augmented thermal resilience, a more refined surface, and pronounced hydrophobicity, albeit at the cost of reduced surface area and pore volume. Remarkably, the STL-5 silica membrane manifested optimum desalination metrics, boasting a salt rejection percentage of 99.99 % and a water flux rate of 5.61 kg m−2 h−1, thereby accentuating the intrinsic trade-off existing between salt rejection and water flux.

An experimental design approach for lead (II) ion removal in an aqueous environment using a composite biofilm from microalgal biomass and pectin

The biosorption of Pb(II) from an aqueous environment was studied using a mixed biofilm of microalgal biomass (Chlorella vulgaris) and natural pectin. A gas sorption analyzer, Fourier transform infrared spectrometer, field emission scanning electron microscope, point of zero charge determination, and texture analyzer were used for the adsorbent’s characterization. Various sorption parameters such as contact time, initial pH, initial metal concentration and temperature were studied. The results were also used to conduct isotherm and kinetic studies. Subsequently, the second-order polynomial model following the response surface methodology was obtained with an R 2 of 0.9941 indicating acceptable accuracy. Under the following condition: an initial pH of 4.27, an initial metal concentration of 300 mg/L, and a temperature of 55.2 °C, a maximum Pb(II) uptake of 121.89 mg/g was observed. The results show that the developed composite biofilm can effectively remove Pb(II) ions from contaminated water.

Preparation and characterization of biocomposite film made of activated carbon derived from microalgal biomass: An experimental design approach for basic yellow 1 removal

The adsorbent is typically used in the form of a fine powder, which can pose challenges when attempting to recover from the liquid after use. This issue has been addressed by encapsulating the fine powder in a biopolymeric material to create a biocomposite film. In this study, activated carbon (AC) powder derived from microalgal biomass and pectin were used to produce this biocomposite film. This film was employed as an adsorbent to remove basic yellow 1 (BY) dye from a liquid solution. The biocomposite film underwent characterization using a gas sorption analyzer, Fourier transform infrared spectrometry, and field emission scanning electron microscopy. The point of zero charge and mechanical properties were also determined. The impact of various factors, including contact time, initial pH, initial dye concentration, and temperature, on BY uptake were investigated. The BY uptake reached equilibrium at 540 min, and the monolayer BY uptake was 57.75 mg/g. Experimental design and response surface methodology were utilized to identify the key factors affecting BY uptake and determine the optimal levels of these factors for maximum BY uptake. Statistical analysis of the derived model yielded an R2 of 0.9997 and a p-value of 9.89 × 10−5, indicating that the optimal conditions were achieved under specific conditions: a solution pH of 2.0, an initial BY concentration of 250 mg/L, and operating temperature of 320 K. These results suggest that the low-cost biocomposite film developed in this study has the potential to effectively remove BY from industrial wastewater.

Molten salt method derived porous carbon with high energy density in KI-additive electrolyte

A series of porous carbons (PCs) with tunable surface areas were prepared by molten salt (NaCl/KCl) method with the assistance of CaCO3. Gas sorption analyses by N2 and CO2 show that the usage of CaCO3 leads to the increasement of in micropores and mesopores, thus enlarging the surface area up to 864 from 425 m2 g−1. Besides, numerous micropores (<0.6 nm) inaccessible to N2 can be detected by CO2. Supercapacitive performance for PCs was also investigated in aqueous KOH, H2SO4 and KI-additive (H2SO4 + KI) electrolytes as well. Combining the results of pore-structure analysis, the investigations on the relationship between specific capacitance and pore-size show that the minimum pore entrance for SO42−, K+ and I− are 0.4, 0.32 and 0.4 nm, respectively. Considering the naked/solvated ionic sizes of SO42− (0.38/0.58 nm), K+ (0.26/0.42 nm) and I− (0.39/0.66 nm), desolvation effect probably occurs in those aqueous electrolytes. Moreover, the effect of oxygen functionalities on the redox reaction was also investigated in this work. It is found that the quinone oxygen species is electrochemically active in both H2SO4 and KI-additive electrolytes. With the addition of KI in electrolyte, the prepared porous carbon-based supercapacitor possesses high specific energy of 55.7 Wh kg−1.

WO3 dispersed on a titanium porous clay heterostructure as a highly efficient visible light-active photocatalyst

Nanocomposites of WO3-dispersed titanium-porous clay heterostructures (W/Ti-PCH) from montmorillonite raw clay were synthesized and reported for the first time in this paper. The nanocomposite was prepared by impregnating tungstophosphoric acid into the titanium-porous clay heterostructure (Ti-PCH). The physicochemical features of the nanocomposite were characterized by using X-ray diffraction (XRD), scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS), high-resolution transmission electron microscopy (HRTEM), UV–visible diffuse reflectance UV–visible spectroscopy (UV-DRS), X-ray photoelectron spectroscopy (XPS) and gas sorption analyses. Identification using XRD and XPS revealed that the dispersion of WO3 anchored on the Ti-PCH surface led to an increase in the band gap energy of the material from 3.1 eV in Ti-PCH to 3.22 eV in W/Ti-PCH. The improved characteristics support the excellent photocatalytic activity for RhB degradation, as 99.99 % removal was achieved after 15 min of treatment.

Synthesis Zeolite Y From Lapindo Mud With Variations Filling Autoclave And Ratio Molar Si/Al

Lapindo mud contains Silicate (SiO2), and Aluminum oxide (Al2O3) that can be utilized to synthesize zeolite Y. Zeolite Y was synthesized from Lapindo mud via the smelting and hydrothermal method, respectively. The thermal activation of Lapindo mud was achieved by leaching smelting at 550oC for 2 hours with NaOH to achieve thed desire adding SiO2, NaOH and aging for 48 hours. The effects of various parameters on the synthesis were investigated. The samples were characterized with X-ray Fluorescence (XRF), X-Ray Diffraction (XRD), Fourier Transformation Infrared Spectroscopy (FTIR) and Gas Sorption Analyzer (GSA). Zeolite Y with high crystallinity was synthesized under optimized conditions, such as filling autoclave 90% and a SiO2/ Al2O3 molar ratio of 15.

Optimization of Mass and Light Transport in Nanoparticle-Based Titania Aerogels.

Aerogels composed of preformed titania nanocrystals exhibit a large surface area, open porosity, and high crystallinity, making these materials appealing for applications in gas-phase photocatalysis. Recent studies on nanoparticle-based titania aerogels have mainly focused on optimizing their composition to improve photocatalytic performance. Little attention has been paid to modification at the microstructural level to control fundamental properties such as gas permeability and light transmittance, although these features are of fundamental importance, especially for photocatalysts of macroscopic size. In this study, we systematically control the porosity and transparency of titania gels and aerogels by adjusting the particle loading and nonsolvent fraction during the gelation step. Mass transport and light transport were assessed by gas permeability and light attenuation measurements, and the results were related to the microstructure determined by gas sorption analysis and scanning electron microscopy. Mass transport through the aerogel network was found to proceed primarily via Knudsen diffusion leading to relatively low permeabilities in the range of 10-5-10-6 m2/s, despite very high porosities of 96-99%. While permeability was found to depend mainly on particle loading, the optical properties are predominantly affected by the amount of nonsolvent during gelation, allowing independent tuning of mass and light transport.

Preparation of Ga\(_{2}\)O\(_{3}\)-modified sulfated zirconia mesopore and its application on cellobiose hydrolysis

Heterogeneous catalyst plays vital role in biomass processing due to slow rate of biological and naturally pathway processes. Solid acid sulfated zirconia (SZ) is a promising catalyst with properties that can be tuned up. Sulfated zirconia was successfully modified by 2%, 5% and 10% (wt.) Ga2O3 (xGa-SZ; x = 2, 5 and 10) via template-assisted sol-gel method. The catalysts were characterized through various method (XRD, SEM-EDS and Gas Sorption analysis) and applied on hydrolysis of cellobiose, a model compound of cellulose. Diffraction pattern showed xGa-SZ formed completely tetragonal phase whereas un-promoted SZ contains mixed phase of monoclinic and tetragonal. Acidity evaluation via gravimetric method using ammonia as probe molecule indicates the Ga2O3 promoted sulfated zirconia has larger acidity. The SEM-EDS results confirmed the presence of Gallium element on the surface of promoted xGa-SZ. Gas sorption analysis shows specific surface area is improved (83 m2∙g-1 to 123 m2∙g-1) and increased pore radii (36 Å to 56 Å). The adsorption-desorption isotherm displayed pattern of meso-porosity material. At higher T and longer time, SZ yield more glucose than xGa-SZ. However, at shorter time, 2Ga-SZ and 10Ga-SZ show better hydrolysis performance. The solid acid 10Ga- SZ shows potential performance as heterogeneous catalyst for cellobiose conversion in modest conditions.

Effect of Arginine-Based Deep Eutectic Solvents on Supported Porous Sorbent for CO2 Capture Analysis

Carbon dioxide (CO2) as one of the heat-trapping gases, has caused global warming. Being a greener and more economical material, amino acid-based deep eutectic solvents (AADES) have attracted interest in CO2 capture applications. In this paper, the effect of L-arginine (Arg) in binary AADES of arginine-ethylene glycol (Arg-EG) and ternary AADES of choline chloride-ethylene glycol-arginine (ChCl-EG-Arg) on adsorption of CO2 was studied. The solubility, basicity, and physicochemical characteristics were compared with the binary DES (ChCl-EG) before and after being impregnated into a silica gel (SG) via the wet impregnation method. The AADES/SG adsorbents were evaluated for CO2 sorption performance using an automated gas sorption analyzer at 100% CO2 loading and thermogravimetric analysis (TGA) at flue gas conditions (15% CO2/85% N2). Findings show the basicity and the nitrogen content (N%) of AADES/SG were increased as Arg was added and DES/AADES functional group peaks (amino, hydroxyl, alkyl groups) were observed after the impregnation. The CO2 sorption of 16.0 mg/g at 25 °C and 1 atm was achieved by 30% Arg-EG(1:8)/SG followed by 30% ChCl-EG-Arg (1:2:0.1)/SG (14.8 mg/g) and 30% ChCl-EG/SG(1:2) (14.5 mg/g) using an Autosorb iQ2 instruments with 100% CO2 loading. The CO2 uptake was increased almost linearly with increasing pressure and decreased with increasing temperature. The Arg-EG(1:8)/SG shows the highest selectivity toward CO2 than other sorbents with 8.10 mg/g adsorption for 1 h at 15% CO2 loading at 25 °C with higher thermal stability and surface area. Considering environmental, technological, and economic viewpoints, the Arg-EG(1:8)/SG can be explored more as a potential solid sorbent for CO2 capture.

Application of plasma modified pyrolytic carbon black in improving mechanical properties of natural rubber composite

AbstractIn this work, the Argon (Ar) plasma technology is adopted for pyrolytic carbon black (CBp) modification and the N330/Modified‐CBp (MCBp) hybrid is then incorporated into the Natural Rubber (NR) matrix. Compared with CBp, the MCBp has smaller particle size, lower ash content, higher specific surface area, and surface activity based on the results of laser diffraction method, transmission electron microscope (TEM), thermogravimetric analysis, gas sorption analysis (Nitrogen), acetone solvent, and X‐ray photoelectron spectroscopy. Among them, Dv (90) is found to have reduced by 20% while the specific surface area increased by 4%. According to the bound rubber content experiments, the equilibrium swelling experiments as well as the temperature and strain sweeps, the bound rubber content, filler‐filler bond strength, and cross‐linking density of NR/N330/MCBp are all superior to those of NR/N330/CBp, resulting in an outstanding comprehensive performance of NR/N330/MCBp composite. In particular, the 300% modulus and the tear strength rise by 43% and 14% respectively, surpassing even the system filled with N330. Finally, the mechanism of mechanical properties improvement in the NR/N330/MCBp composite is proposed: the strong filler‐filler bond is formed between the MCBp and N330 aggregates via molecular chains, and they are anchored on the MCBp and absorbed on the N330 simultaneously.

Gas sorption properties of a new Zn‐BTB metal–organic framework with permanent porosity

AbstractA new three‐dimensional (3D) Zn‐based metal–organic framework (Zn‐MOF) with 1,3,5‐benzenetribenzoate (BTB3−), [Zn4O(BTB)2(0.5H2O)4]·H2O·8DEF (1), has been prepared using the reaction between Zn(NO3)2·6H2O and a tritopic bridging ligand 1,3,5‐benzenetribenzoic acid (H3BTB) in the presence of a potentially ditopic bridging ligand 3,3′‐terphenyldicarboxylic acid (H2TPDC). Interestingly, TPDC2− ligand did not incorporate into the resulting Zn‐MOF, and the title compound was not formed in the absence of TPDC2− ligand during the synthesis. After the solvate molecules were removed, Zn‐MOF 1 exhibited a doubly interpenetrated 3D ant net with a large solvent accessible void. The powder x‐ray diffraction pattern of the evacuated 1 did not change significantly compared to that of the as‐prepared 1, thus indicating that 1 has permanent porosity. Gas sorption analyses were performed to investigate the sorption abilities of the evacuated 1 by using several different gases at suitable temperatures: N2, CO2, H2, and CH4.

Enhanced Photodegradation of Rhodamine B Using Visible-Light Sensitive N-TiO2/rGO Composite

Rhodamine B (RhB) is extensively used for dyeing purposes, and cannot be completely removed using traditional water treatment technologies. Here, we report for the first time the photodegradation of RhB using nitrogen-doped titanium dioxide (N-TiO2) on reduced graphene oxide (rGO) composite (N-TiO2/rGO). The work primarily highlights the synergistic effect of the incorporation of N-TiO2 and rGO and its kinetic study for the photodegradation of RhB. The N-TiO2/rGO composite was synthesized by dispersing titanium(IV) isopropoxide and urea, followed by annealing treatment via the hydrothermal method with rGO. Scanning electron microscopy (SEM) images illustrated that N-TiO2 particles with an irregular round shape and white color were dispersed onto the rGO surface. X-Ray diffraction (XRD) patterns revealed that N-TiO2/rGO composite showed an anatase phase of TiO2 with a diffraction peak of 2θ = 25.622°. The gas sorption analysis (GSA) showed that N-TiO2/rGO had surface area, pore volume, and pore size of 53.393 m2/g, 0.096 cc/g, and 3.588 nm, respectively. The thermogravimetric-differential thermal analysis (TG-DTA) showed an anatase phase of TiO2 that appeared at a temperature of 200–500 °C, with a weight loss of 2.50%. According to the ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) study, TiO2, N-TiO2, and N-TiO2/rGO had band gap energies of 3.25, 2.95, and 2.86 eV, respectively. The highest photodegradation of RhB was obtained at the optimum condition in pH 2 with a photocatalyst mass of 20 mg and an irradiation time of 90 min. The photocatalytic activity of N-TiO2/rGO using visible light showed a higher percentage of photodegradation at 78.29%, compared to 44.08% under UV light. The kinetic study of the photodegradation of RhB using N-TiO2/rGO followed the pseudo-second-order model.