Mesopore Volume Research Articles

Generation of mesoporosity in H–Y zeolites by basic or acid/basic treatments: Towards a guideline of optimal Si/Al ratio and basic reagent

We elaborate a post-modification method for faujasite zeolite to introduce additional mesopore volume, by desilication (if necessary combined with prior dealumination). CBV712 (Si/Al = 6), CBV720 (15), and CBV760 (28) were used as starting materials. We employ tetraalkylammonium hydroxide (TAAOH) as desilicating agent, varying its alkyl chain from C1 to C4. The different sizes of TAAOH show different modulating capacities in pore generation. Short alkyl chains generate a lot of mesopores, but also lead to extended amorphization. The opposite holds true for long alkyl chains. The desilication treatment was unsuccessful for CBV712, because of its too high Al content. CBV712, was therefore dealuminated by oxalic acid, to different extents, before applying TAAOH. This allowed us to identify the optimal Si/Al range for the desilication treatment, i.e. between 15 and 28. We also examined the accessibility of active sites in mesoporous zeolites by the sterically hindered base 2,4,6-tri-tert-butylpyridine (TTBPy).

Preparation of Co-C/N flower-like single-atom catalysts via TCPP coordination confinement for enhanced activation of peroxymonosulfate

The design and preparation of highly efficient advanced oxidation processes (AOPs) catalysts is a crucial research area in the field of water pollution control. Herein, a single-atom AOP catalyst Co-N/C material (TPM-650) has been synthesized through the pyrolysis of the flower-shaped Co-TCPP MOF precursor, which is designed based on coordination confinement with TCPP. HAADF-STEM image analysis confirms the uniform distribution of single Co atoms throughout the TPM-650 material, which served as the highly efficient catalytic centers and can achieve 99.99% catalytic degradation of MG dyes in 24 min with only trace dosage ([TPM-650] = 1 mg/L, pseudo-first-order kinetic model, Kobs=0.302 min−1) and low leaching of Co ions (0.348 μg/L). Under optimal condition, the degradation of MG exhibits a high turnover number (dTON) of 68.5 mmol h−1 gcat−1 and a significant reduction in total organic carbon (TOC) by 58.7%. Radical quenching experiments and EPR measurements demonstrated that various reactive oxygen species (•SO4−, •OH, 1O2, MIV(O)/MV(O)) contributes to accelerating MG degradation. The enhanced efficiency and stability were attributed to the ultrathin layer supported single-atom Co-N/C structure, high mesopore volume, and synergy between the catalyst and peroxymonsulfate (PMS) with a synergy index of 16.5. This study not only reports a highly efficient and stable advanced oxidation catalyst Co-N/C, but also confirms that the nitrogen-coordinated Co sites are the primary active sites responsible for PMS activation; thus providing valuable insights into designing efficient transition metal-based AOP catalyst via coordination method for environmental remediation.

Electrospinning prepared nickel-based carbon fibers with enhanced adsorption capacity for adsorption desulfurization of fuels

Enhanced adsorption capacity of adsorbents with excellent regeneration properties always remained the focus of researchers in the adsorptive desulfurization (ADS) technology. In this paper, we report an electrospinning method to prepare nickel-based carbon fibers (NCF), and their adsorption desulfurization performance was compared with those of nickel-based carbon particles (NCP) obtained via traditional solid-state grinding method. The results demonstrated that compared with NCP, NCF contained more abundant mesoporous specific surface area and mesopore volume, well-distributed active metal sites, which would be beneficial to their enhanced adsorption desulfurization performance. As a result, the adsorption capacity of NCF was as high as 13.13 mg S/g in the ADS of thiophene, and its regeneration performance was also far better than that of NCP. In addition, the adsorption process of thiophene was briefly analyzed from the perspective of kinetics, which demonstrated that the adsorption of thiophene in NCF and NCP were both in accordance with the pseudo-second-order kinetic model.

The synthesis of hierarchical ZSM-22 zeolite with only the PHMB template for hydroisomerization of n-hexadecane

The ZSM-22 zeolite has become an effective support for the hydroisomerization of n-alkanes due to its one-dimensional pore structure, good hydrothermal stability and simple synthesis process. However, the diffusion resistance of hydrocarbons in the microporous channel still limits the further industrial application of the traditional microporous ZSM-22 zeolites. To overcome the diffusion limitation, the different amounts of polyhexamethylene biguanide (PHMB) was added into the initial gel as the only template instead of 1,6-diaminohexane (DAH) to synthesize a series of hierarchcal ZSM-22 zeolites (Z22-xP), and the corresponding Pd/ZSM-22 catalysts with 0.5 wt% Pd loading were then prepared for n-hexadecane hydroisomerization in this work. The characteristic results show that, the Z22-xP samples exhibit improved mesoporous volume and external surface than those of the traditional microporous Z22-D sample. Additionally, the Z22-xP samples also demonstrates significantly lower Brønsted acid density in comparison with the microporous Z22-D sample because of the proportion decrease of T1-T3 skeleton Al atoms. The catalytic tests results indicate that the employment of PHMB instead of DAH can effectively promote the catalytic performance. The Pd/Z22-0.002P catalyst reveals the highest iso-hexadecane yield of 76.6 % among all catalysts. Therefore, this work provides a more convenient and effective way for the development of potential bifunctional catalysts with promoted catalytic performance.

Mesoporous graphitic carbon electrodes derived from boat-fruited shells of Sterculia Foetida for symmetric supercapacitors for energy storage applications

In recent years, intensive research efforts have focused on translating biomass waste into value-added carbon materials broadcasted for their significant role in energy and environmental applications. For the first time, high-performance carbonaceous materials for energy storage applications were developed from the multi-void structure of the boat-fruited shells of Sterculia Foetida (SF). In that view, synthesized mesoporous graphitic activated carbon (g-AC) via the combination of carbonization at various elevating temperatures of 700, 800, and 900 °C, respectively, and alkali activation by KOH, with a high specific surface area of 1040.5 m2 g−1 and a mesopore volume of 0.295 cm3 g−1. In a three-electrode configuration, the improved electrode (SF–K900) exhibited excellent electrochemical behavior, which was observed in an aqueous electrolyte (1 M H2SO4) with a high specific capacitance of 308.6 F/g at a current density of 1 A/g, owing to the interconnected mesopore structures and high surface area of SF-K900. The symmetric supercapacitor (SSC) delivered the specific capacitance of 138 F/g at 1 A/g with a high energy density (ED) of 13.4 Wh/kg at the power density (PD) of 24.12 kW/kg with remarkable cycle stability and supercapacitive retention of 93% over 5000 cycles. Based on the findings, it is possible to develop low-cost active electrode materials for high-rate performance SSC using mesoporous g-AC derived from SF boat-fruited shells.

Nanocrystallite Zeolite BEA for Regioselective and Continuous Acetyl Functionalization of Anisole Using Acetic Anhydride: Catalyst Deactivation Studies.

Ultrasonic pretreatment of gel composition followed by hydrothermal synthesis produces the nanocrystallite zeolite beta (ZB) with crystal sizes of 10.3, 22.6, and 9.1 nm for ZB-1, ZB-2, and ZB-3, respectively. The effect of ultrasonic pretreatment and the (SiO2/Al2O3) ratio of gel composition on physical, textural properties, and also on the catalytic activity of ZB catalysts with increasing time on stream (TOS) was investigated. The specific surface area and mesopore volume for ZB-1, ZB-2, and ZB-3 are 438, 380, and 429 m2/g and 0.17, 0.05, and 0.14 cm3/g, respectively. The activity studies of ZB-1 and ZB-3 catalysts were confirmed that the anisole conversion initially increased with TOS until it attained the maximum value and then started decreasing further with TOS due to the deactivation of the catalyst caused by the strong interaction of the product with the acidic sites in the mesopore region. However, in the case of ZB-2, the anisole conversion (>45%) was sustained for a longer TOS due to its smaller particle size, low mesopore volume, and more acidic sites in the micropore volume that are inclusively made for retardation in the catlytic deactivation rate. The CHNS and TGA analysis of the spent catalysts confirm that ZB-1 and ZB-3 catalysts are susceptible for a significant coke formation attributed due to strong product retention in their large mesopore volume, which lead to the catalytic deactivation.

Constructing Intrapenetrated Hierarchical Zeolites with Highly Complete Framework via Protozeolite Seeding.

Creation of intrapenetrated mesopores with open highway from external surface into the interior of zeolite crystals are highly desirable that can significantly improve the molecular transport and active sites accessibility of microporous zeolites to afford enhanced catalytic properties. Here, different from traditional zeolite-seeded methods that generally produced isolated mesopores in zeolites, nanosized amorphous protozeolites with embryo structure of zeolites were used as seeds for the construction of single-crystalline hierarchical ZSM-5 zeolites with intrapenetrated mesopores (mesopore volume of 0.51 cm3 g-1 ) and highly complete framework. In this strategy, in contrast to the conventional synthesis, only a small amount of organic structure directing agents and a low crystallization temperature were adopted to promise the protozeolites as the dominant growth directing sites to induce crystallization. The protozeolite nanoseeds provided abundant nucleation sites for surrounding precursors to be crystallized, followed by oriented coalescence of crystallites resulting in the formation of intrapenetrated mesopores. The as-prepared hierarchical ZSM-5 zeolites exhibited ultra-long lifetime of 443.9 hours and a high propylene selectivity of 47.92 % at a WHSV of 2 h-1 in the methanol-to-propylene reaction. This work provides a facile protozeolite-seeded strategy for the synthesis of intrapenetrated hierarchical zeolites that are highly effective for catalytic applications.

Constructing Intrapenetrated Hierarchical Zeolites with Highly Complete Framework via Protozeolite Seeding

AbstractCreation of intrapenetrated mesopores with open highway from external surface into the interior of zeolite crystals are highly desirable that can significantly improve the molecular transport and active sites accessibility of microporous zeolites to afford enhanced catalytic properties. Here, different from traditional zeolite‐seeded methods that generally produced isolated mesopores in zeolites, nanosized amorphous protozeolites with embryo structure of zeolites were used as seeds for the construction of single‐crystalline hierarchical ZSM‐5 zeolites with intrapenetrated mesopores (mesopore volume of 0.51 cm3 g−1) and highly complete framework. In this strategy, in contrast to the conventional synthesis, only a small amount of organic structure directing agents and a low crystallization temperature were adopted to promise the protozeolites as the dominant growth directing sites to induce crystallization. The protozeolite nanoseeds provided abundant nucleation sites for surrounding precursors to be crystallized, followed by oriented coalescence of crystallites resulting in the formation of intrapenetrated mesopores. The as‐prepared hierarchical ZSM‐5 zeolites exhibited ultra‐long lifetime of 443.9 hours and a high propylene selectivity of 47.92 % at a WHSV of 2 h−1 in the methanol‐to‐propylene reaction. This work provides a facile protozeolite‐seeded strategy for the synthesis of intrapenetrated hierarchical zeolites that are highly effective for catalytic applications.

Mechanisms of cadmium adsorption by ramie nano-biochar with different aged treatments

Biochar (BC) has proven to be very effective against the remediation of cadmium contamination. However, aged treatment is inevitable and variations in the adsorption mechanism caused by ageing remain unclear. In this study, different treatments (i.e., photo-aged (nano-PBC) and chemical treatment (nano-NBC)) were used on the nano-BC. The nano-BC as well as the two aged nano-BCs were characterized separately to examine their surface morphology, functional groups, and variations in phase composition. The aged nano-BCs exhibited larger specific surface area and mesopore volume. The nano-NBC produced more surface functional groups (i.e., carboxyl groups, lactone groups, and phenolic hydroxyl groups) compared to the nano-BC and nano-PBC. In addition, the study revealed the effect of aged treatment on the adsorption mechanism of the nano-BCs by adsorption kinetic model and adsorption isotherm model, respectively. The fitted consequences revealed that the adsorption of Cd by the three nano-BCs was consistent with the pseudo-second order kinetic model and the Langmuir adsorption isotherm model. The aged nano-BCs have higher Cd adsorption capacity, which was more effective for the nano-NBC. In addition, different adsorption conditions (i.e., pH, ionic strength, coexisting cations, and initial nano-BCs addition concentration) were performed to explore the optimal adsorption capacity. The results showed the optimal adsorption efficiency of 93.24 % was achieved for nano-NBC at pH 7, a background solution of 0.001 M Na+, and an initial nano-BC addition concentration of 50 mg L−1. The different aged treatments did not significantly affect the adsorption mechanism of the nano-BCs, but changed the chemisorption mode and enhanced the physical adsorption (pore size filling and hydrogen bonding). Namely, aged treatment significantly enhanced the adsorption capacity of the nano-BCs on Cd.

Nano-Scale Pore Structure Characterization and Its Controlling Factors in Wufeng and Longmaxi Shale in the Zigong Area, Southwest Sichuan Basin

The nano-scale pore systems in shale reservoirs control shale gas transportation and aggregation, which is of great significance for the resource evaluation of shale oil and gas and the selection of a “sweet spot”. Taking twelve marine shale samples from the Wufeng–Longmaxi Formation in the Zigong area, southwest Sichuan Basin, as the research target, we carried out a series of experiments, including total organic carbon (TOC) analysis, X-ray diffraction (XRD), gas adsorption (CO2 + N2), and mercury intrusion porosimetry (MIP), to study the full-scale pore structure characterization and controlling factors of pore volume and specific surface area. The results presented the following findings. (1) Marine shale samples from the target area are rich in organic matter, with an average TOC value of 3.86%; additionally, the mineral composition was dominated by quartz and clay minerals, with average contents of 44.1% and 31.4%, respectively. (2) The full-scale pore size distribution curves of pore volume developed multimodally, with the main peaks at 0.5 nm–2 nm, 3 nm–6 nm, and 700 nm–2.2 um; moreover, the full-scale pore size distribution curves of a specific surface area developed unimodally, with the main peak ranging from 0.5 nm to 1.2 nm. (3) Pore volume was mainly contributed by mesopores and macropores, with an average contribution of 46.66% and 42.42%, respectively, while the contribution of micropores was only 10.91%. The specific surface area was mainly contributed by micropores and mesopores, with an average contribution of 64.63% and 29.22%, respectively, whereas the contribution of micropores was only 6.15%. (4) The TOC content mainly controlled the pore volume and specific surface area of micropores and mesopores, while the clay and feldspar content generally controlled the pore volume and specific surface area of macropores. Additionally, the quartz content had an inhibitory effect on the development of all pore types. These results will help researchers understand the laws of gas accumulation and migration.

Easily Pyrolyzable Biomass Components Significantly Affect the Physicochemical Properties and Water-Holding Capacity of the Pyrolyzed Biochar

The influences of feedstocks on biochar properties are widely reported. However, the influence of the transformation of biomass components (mainly cellulose, hemicellulose, and lignin) during feedstock pyrolysis on the obtained biochar has not been clearly stated. Here, biochar was pyrolyzed from four biomass types with different fractions of the three main components, of which surface area, pore structure, functional group, and thermogravimetric analyses were conducted. Further, we investigated the links among the physicochemical properties and water-holding capacity (WHC) of the biochar by measuring the WHC of a biochar–silica-sand (SS) mixture. Cellulose and hemicellulose were considered the easily pyrolyzable components of the feedstock owing to their low thermal stabilities. Additionally, the thermal decomposition of the easily pyrolyzable components caused the disappearance of most functional groups from the biochar that was synthesized at >350 °C. Moreover, the WHC of the biochar–SS mixture correlated significantly with the surface area and pore volumes of the biochar. Notably, the thermal residual mass and the WHC of the biochar–SS mixture exhibited the strongest correlation. Poplar wood sawdust (PT), which accounted for the highest mesopore volume of the biochar sample, contained the highest amount (86.09%) of the easily pyrolyzable components. The PT-derived biochar exhibited superior WHC than other biochar types, indicating that the dehydration, deoxygenation, and condensation of the easily pyrolyzable components of biomasses promoted gradual pore formation, further contributing to the increased WHC of the mixture. Rather than high-temperature-pyrolyzed biochar, PT350 demonstrated the highest WHC (599 mg/g), revealing that attention should be drawn to the contribution of low-temperature-pyrolyzed biochar to soil water retention in future research.

Fabrication of an efficient hierarchical mesoporous 2D-MoS2/CNT/polypyrrole based composite electrodes for competitive and selective U6+ removal using capacitive deionization: Mechanistic evaluation through cyclic voltammetry

In this work, efficient and selective carbonaceous electrode materials based on hierarchical mesoporous functionalized carbon nanotubes, 2D-MoS2 nanosheets electrodeposited with variable content of polypyrrole (PPy) were prepared. The simple etching reaction between HNO3 and carbon nanotubes did not only modify the surface but also improved its hydrophilicity. The annealing of carbon nanotubes and electrodeposition of PPy increased the mesopore volume to total volume ratio (Vmeso/Vt) from 0.42 to 0.86. The composite materials were characterized wisely using different characterization techniques and employed for efficient U6+ electro-assisted sorption through capacitive deionization. Electrode material with PPy content (0.3 M) exhibited good specific capacitance Csp (100.2 F/g), improved Vmeso (0.61 cm3/g), superb Vmeso/Vt ratio (0.86) and large specific surface area SBET (149.7 m2/g). The stated electrode showed fast sorption kinetics (teq=30 min), admirable selectivity and exhibited the experimental sorption capacity of 274.50 mg/g at − 0.90 V. Electrochemical impendence spectroscopic study revealed that the resulting material exhibited relatively small charge transfer resistance (1.19 Ωcm2), minute electrolytic resistance (0.91 Ωcm2) and large double layer constant phase element (0.0368 S sn/ cm2). These significant characteristics promoted U6+ ions diffusion inside the hierarchical porous electrode surface for better performance of electrosorption process. This new class of hierarchical mesoporous composite electrodes may be used as potential supercapacitor materials not only for removal of uranium but also for other potent desalination applications.

Boosted ultrasound-sunlight-driven removal of organic pollutant over double Z-scheme plasmonic ZnO–Cu–CuO/g-C3N4 nanophotocatalyst: design via in-situ co-precipitation hybrid with various sonication powers

Herein, the sonophotocatalytic degradation of the organic pollutant is studied over double Z-scheme plasmonic ZnO–Cu–CuO hybridized two-dimensional C3N4, which is designed with an in-situ co-precipitation manner hybrid with sonicated irradiation. The sonication power effect on semiconductor properties is studied at P = 0, 30, 60, and 90 W, and the sonophotocatalysis test is done at constant power (P = 60 W) and simulated sunlight irradiation in order to find optimal properties. XRD, FESEM, 3D texture, TEM, EDX, BET–BJH, and DRS were used to determine the physicochemical characteristics and ultrasound effect on nano semiconductors. XRD analysis shows that Cu nanoparticles have been observed in heterostructured catalysts synthesized by ultrasound waves, except ZnO–Cu–CuO/C3N4 (P = 0). And with an increase in sonication power, the intensity of plasmonic Cu particles decreased. According to FESEM and 3D texture analysis, the surface roughness is reduced, which shows nanoparticles' good-fit nucleation and dispersion. More importantly, the total pore volume for ZnO–Cu–CuO/g-C3N4 (P = 0) and ZnO–Cu–CuO/g-C3N4 (P = 90) is 0.076 and 0.096 cm3/g, respectively in which the mesopores volume for ZnO–Cu–CuO/g-C3N4 (P = 90) sample (0.0622cm3/g) is more, facilitating the penetration of pollutants and products. DRS revealed that by increasing Cu nanoparticles, the band gap of ZnO–Cu–CuO/C3N4 (P = 90) is tuned in the visible-light region (Eg = 1.54 eV). The highest sonophotocatalytic degradation of 20 mg/L of methylene blue was obtained at 97.9% over ZnO–Cu–CuO/C3N4 (P = 90) and 60 W ultrasound irradiation, after 120 min of sonophotocatalysis treatment.

Nanopore Structure and Multifractal Characteristics of Continental Shale Oil Reservoir: A Case Study from Ziliujing Shales in the Sichuan Basin

Thermal maturity of the shales from the Ziliujing Formation of the Jurassic age in the Sichuan Basin is in the hydrocarbon generation window, which makes it a candidate for shale oil and gas development. The meso- and macropore characteristics and heterogeneity of shales are important factors affecting the occurrence and development of oil and gas. However, the meso- and macropores of the Ziliujing shales have not been systematically studied. Thus, the mineral compositions and total organic carbon (TOC) of samples from this formation, as well as its pore structure, are analyzed by low-temperature N2 adsorption technique. Moreover, the heterogeneity of the pores was determined by multifractal analysis. The results show that the Ziliujing shales can be classified into three types according to the distributions of mineral compositions of carbonate and mixed and argillaceous shales. Results revealed that the smallest meso- and macropore volume (PV), the smallest specific surface area (SSA), and the largest average pore diameter (APD) occur in the carbonate shales. However, the largest PV and SSA and the smallest APD are observed in the argillaceous shales. The porosity of carbonate shales is mainly concentrated between 5 nm and 30 nm. Compared with carbonate shales, the porosity with pore sizes less than 30 nm of mixed and argillaceous shales shows a rapid increase. Furthermore, inorganic minerals are the main factors affecting the pore distributions, while TOC shows a weak effect. Herein, clay minerals significantly increase the mesopore volume and the pore number with a size of less than 30 nm. The Dq-q curves reveal that the meso- and macropore distributions of Ziliujing shales show multifractal behavior, but the multifractal characteristics of pores of various shales are distinctly different. The information dimension D1, the Hurst exponent H, and the width of the right side D0–D10 are key indicators to distinguish the local variations within the pore structure of different types of shales. The carbonate shales have the largest multifractal spectra width and the smallest D1 and H, while the opposite trend is found for the argillaceous shales. Clay minerals reduce the heterogeneity of the meso- and macropore distributions and increase the pore connectivity. Nevertheless, the carbonate minerals exhibit a reverse trend. Finally, it was found that TOC does not impact pore complexity as much. Collectively, this study supports our understanding of the occurrence of shale oil within various reservoir facies, thereby providing a guideline for future explorations in the Ziliujing Formation of the Jurassic age in the Sichuan Basin.

Activation-self-activation craft for one-step synthesis of GO-inbuilt mesopore-dominated N-doped hierarchical porous carbon in capacitive deionization capture of Ni(II)

Capacitive deionization (CDI) is considered a polar-promising technology to remove heavy-metal ions from wastewater. Herein, a green activation-self-activation strategy was exploited to build graphene (GO)-inbuilt mesopore-dominated N-doped hierarchical porous carbons (ENHPCs) using sodium lignosulfonate (SLS) as carbon sources/self-activators. Different from SLS self-activation and K2C2O4-SLS activation-self-activation, ENHPCLKG gained via GO-mediated K2C2O4-SLS activation-self-activation showed suitable mesopore-dominated micro-mesoporous structures with high surface area of 1795.5 m2/g, large mesoporous volume of 0.87 m3/g, 3.65 % N-doping and excellent conductivity. Its unique hierarchical porous structure and abundant active sites facilitated the ion rapid insertion and extraction. When utilized to capture low-concentration nickel (Ni2+) ions, ENHPCLKG delivered splendid salt removal capacity of 17.86 mg/g, rapid average salt removal rate of 0.99 mg/g/min and standout cycle stability. Meanwhile, ENHPCLKG was further extended to remove NaCl, MgCl2, CaCl2 and Ni-containing wastewater, showing superior CDI property. Moreover, the recycled ENHPCLKG (10th) taken to eliminate indomethacin (IDM) depicted a splendid adsorption capacity. This work proved the significant applicant potential of the novel and green ENHPCLKG for disposing of Ni2+ ions via CDI technology.

The Adsorption of 2,4-Dichlorobenzoic Acid on Carbon Nanofibers Produced by Catalytic Pyrolysis of Trichloroethylene and Acetonitrile

In this study, carbon nanofibers were synthesized by the catalytic pyrolysis of trichloroethylene (CNF-Cl) and its mixture with acetonitrile (CNF-Cl-N). The addition of acetonitrile resulted in the incorporation of nitrogen in the CNF (0.33 at%), the removal of chlorine, an increase in oxygen-containing functional groups on the surface (from 1.6 to 3.6 at%), and an increase in the volume of mesopores (from 0.35 to 0.41 cm3·g−1) and macropores (from 0.115 to 0.393 cm3·g−1). The study of 2,4-DCBA adsorption on both CNFs revealed that the adsorption capacity showed dependence with a maximum on the 2,4-DCBA concentration in the solution, which was attributed to the electrostatic interactions of adsorbate with adsorbent at various pHs. The adsorption forces were effective over distances greater than the size of the 2,4-DCBA molecule, indicating volume pore filling. The maximum adsorption capacity occurred at 0.7–1.2 mM and a pH of 3.4 ± 0.1. CNF-Cl-N exhibited lower 2,4-DCBA adsorption than CNF-Cl-N due to its lower specific surface area, lower micropore volume, and higher concentration of oxygen-containing groups on the surface. However, these differences were not significant, suggesting that CNFs produced from both chlorine-containing wastes and their mixtures with nitrogen-containing compounds can be effectively used for water treatment to remove 2,4-DCBA.

Li2C2O4 with 3D confinement as simultaneous sacrificial material and activation reagent of biomass-derived carbon for advanced lithium-ion capacitors

Inappropriate pore size distribution and the lack of a suitable lithium-cation source in the device are the key issues limiting the industrial application of biowaste carbon-based lithium-ion capacitors (LICs) to achieve both high energy density and power density for energy storage. Herein, the Li2O nanowires, decomposed from Li2C2O4 under three-dimensional confinement provided by wasted feather-derived carbon, are introduced as a sacrificial material for self-prelithiation activated carbon materials (prAC) cathode preparation with a high practical specific capacity of 1376 mAh/g. Accompanied by the in-situ formation of Li2O, the volume of mesopores increases significantly to 0.319 cm3/g (32.1 vol% of the total pore volume) by activation with CO2 yielded by the decomposition of Li2C2O4. The assembled prAC/graphite LIC demonstrates a high energy density of (122 Wh/kg at 220 W/kg) and a high power density (13 kW/kg at 30 Wh/kg), as well as a superior lifespan of 10,000 cycles at 1 A/g.

Construction of N-Rich Aminal-Linked Porous Organic Polymers for Outstanding Precombustion CO2 Capture and H2 Purification: A Combined Experimental and Theoretical Study.

A large number of scientific investigations are needed for developing a sustainable solid sorbent material for precombustion CO2 capture in the integrated gasification combined cycle (IGCC) that is accountable for the industrial coproduction of hydrogen and electricity. Keeping in mind the industrially relevant conditions (high pressure, high temperature, and humidity) as well as good CO2/H2 selectivity, we explored a series of sorbent materials. An all-rounder player in this game is the porous organic polymers (POPs) that are thermally and chemically stable, easily scalable, and precisely tunable. In the present investigation, we successfully synthesized two nitrogen-rich POPs by extended Schiff-base condensation reactions. Among these two porous polymers, TBAL-POP-2 exhibits high CO2 uptake capacity at 30 bar pressure (57.2, 18.7, and 15.9 mmol g-1 at 273, 298, and 313 K temperatures, respectively). CO2/H2 selectivities of TBAL-POP-1 and 2 at 25 °C are 434.35 and 477.93, respectively. On the other hand, at 313 K the CO2/H2 selectivities of TBAL-POP-1 and 2 are 296.92 and 421.58, respectively. Another important feature to win the race in the search of good sorbents is CO2 capture capacity at room temperature, which is very high for TBAL-POP-2 (15.61 mmol g-1 at 298 K for 30 to 1 bar pressure swing). High BET surface area and good mesopore volume along with a large nitrogen content in the framework make TBAL-POP-2 an excellent sorbent material for precombustion CO2 capture and H2 purification.

Effect of seed on synthesis of binder‐free mordenite for dimethyl ether carbonylation

AbstractA series of binder‐free mordenite (MOR) zeolites were successfully prepared by hydrothermal conversion of shaped precursors containing aluminosilicate and MOR seeds. In the synthesis of seed crystals, hexadecyltrimethylammonium bromide (CTAB) was used as a crystal growth inhibitor as well as a pore filler to adjust the morphology and introduce mesoporous pores. As a result, large aggregates, assembled nanosheets, and flowers‐like MOR were successfully synthesized with these MOR seeds. The effect of seed morphology on the performance of the binder‐free MOR was studied by scanning electron microscopy (SEM), N2 adsorption–desorption, and NH3‐TPD characterization techniques. It was found that the mesopore volume of formed MOR was positively correlated with those of the seeds. The synthesized binder‐free MOR showed high activity (0.28 g methyl acetate gcat−1 h−1), 100% selectivity, and high stability in dimethyl ether (DME) carbonylation to methyl acetate, which can be attributed to the larger surface area and more mesopores. The synthesis of MOR nano‐assemblies via this cost‐effective strategy has a wide range of potential applications.

Synthesis and physicochemical characterization of mesoporous hydroxyapatite and its application in toothpaste formulation

The key characteristics of mesoporous hydroxyapatite, such as high porosity and expansive surface area, along with its biocompatibility with dental tissues and potential as a delivery vehicle for active ingredients, have recently garnered significant research focus. In the present study, mesoporous hydroxyapatite was synthesized using a precipitation technique and was subsequently characterized via X-ray diffraction, Fourier transform infrared, dynamic light scattering, field emission scanning electron microscopy and N2 adsorption–desorption isotherms. The results revealed that the synthesized mesopore particles exhibited significant adsorption potential, and were thereby considered a carrier of thymol, an effective antibacterial on oral pathogens. Specifically, mesoporous hydroxyapatite's surface area and pore volume were approximately 2.66-fold and 1.95-fold higher than hydroxyapatite's. A statistically significant divergence in the release profiles of thymol from thymol-loaded mesoporous hydroxyapatite and thymol-loaded hydroxyapatite was noted, as indicated by the similarity factor (f2 < 50). Evaluation of organoleptic parameters (taste, odor, smoothness, appearance) showed that thymol-loaded mesoporous hydroxyapatite toothpaste had superior organoleptic attributes compared to thymol-loaded hydroxyapatite toothpaste. However, both formulations were acceptable regarding pH and stability and were desirable regarding abrasiveness with no significant difference compared to the standard formulation (p > 0.05). Overall, the findings demonstrate the suitability of mesoporous hydroxyapatite as an abrasive material for developing hydroxyapatite-based toothpaste formulations.