Mesoporous Morphology Research Articles

Synthesis of alumina/ferric oxide nanofibers and application to catalysts for ethanol dehydration reaction by adding palladium oxide

AbstractAlumina/ferric oxide (Al₂O₃/Fe₂O₃) composite nanofibers were fabricated via electrospinning followed by heat treatment. Structural characterization revealed mesoporous morphology with high porosity and surface area and uniform dispersion of catalytically active Fe₂O₃ nanoparticles. Catalytic evaluation for ethanol dehydration demonstrated superior performance for nanofibers containing 5 wt% Fe₂O₃, attributed to their unique structural features. Further enhancement was achieved by incorporating palladium oxide (PdO), resulting in improved catalytic activity, particularly in ethylene productivity. Surface acid properties were altered with PdO addition, suggesting a role of Lewis acid sites in augmenting catalytic performance. The developed PdO/Al₂O₃/Fe₂O₃ nanofibers exhibit stable performance over multiple cycles, offering promising prospects for efficient ethanol dehydration catalysts.

Amino acid assisted-construction of 2D-hierarchical MFI zeolites for adsorption of rhodamine B

Hierarchical and two-dimensional (2D) zeolites have drawn much attention in catalysis and separation process due to their fast mass transfer. However, the facile manipulation in controllable mesopore volumes and morphologies for hierarchical nanozeolites is full of challenges. Herein, a facile strategy is presented for the synthesis of single-crystalline 2D hierarchical MFI zeolite nanosheets (HNSs) with tunable mesopore volumes through the amino acid-assisted crystallization of nucleated amorphous silicon precursors (NASPs). The tailored synthesis of HNSs with controllable aspect ratios ((Lc + La)/Lb), b-axis thicknesses (a few tens of nanometers) and mesopore volumes is achieved by adjusting the preparation of the NASPs and the amount of amino acid in the synthesis mixture. The HNSs exhibit large BET surface area (>400 m2/g), high micropore volume (0.16–0.18 cm3 g−1) as well as rich mesopore volume (>0.10 cm3 g−1), indicating the high crystallinity of the hierarchical zeolite nanosheets. Specially, the higher adsorption capability and faster adsorption rate for the dye (Rhodamine B) adsorption demonstrate the excellent performance of the hierarchical zeolite nanosheets, which exhibit the maximum adsorption capacity of 115.7 mg g−1. The controllable manipulation of mesoporous volumes and morphologies in MFI zeolites represents a significant contribution to the field of zeolite microstructure engineering.

Improved electrochemical performance of the iron-doped NiO nanoparticles at varying calcination temperatures and examination of their supercapacitor applications

The scientific community is interested in increasing oxide electrochemical characteristics for supercapacitor applications. The present research explores the development of supercapacitor electrodes using Fe-doped NiO nanoparticles synthesised via chemical co-precipitation method with varied calcination temperatures (350, 550, and 750 °C). The key innovation of the work lies in the systematic investigation of the effects of calcination temperature on the electrochemical properties and structural characteristics of the Fe-doped NiO nanoparticles. X-ray diffraction (XRD) analysis revealed a trend of increasing crystallite size with rising temperatures, and optical studies indicated a decreasing trend in the energy band gap from 3.67 eV to 3.23 eV. Fourier transform infrared (FTIR) spectroscopy confirmed the metal-oxygen bond in the molecules. Scanning electron microscopy (SEM) and High-Resolution Transmission Electron Microscopy (HR-TEM) analysis showed the mesoporous spherical morphology of the nanoparticles. Energy-dispersive X-ray spectroscopy (EDX) ensured the samples' elemental composition purity. Brunauer–Emmett–Teller (BET) shows a specific surface area of around 180.8 m2/g was obtained for Fe-doped NiO nanoparticles at 350 °C. Electrochemical tests demonstrated that the Fe-doped NiO electrodes, especially calcined at 350 °C, exhibit superior specific capacitance values (635 F/g) and impressive cycle stability with 93.29 % capacitance retention after 5000 cycles. The present demonstrates the potential of optimizing calcination temperatures to enhance the electrochemical performance and stability of Fe-doped NiO supercapacitor electrodes, marking a significant advancement in supercapacitor technology.

The release behavior and in vitro osteogenesis of quercetin-loaded bioactive glass/hyaluronic acid/sodium alginate nanocomposite paste

Injectable pastes based on bioactive compounds and natural polymers are of interest in non-invasive bone surgeries. Several quantities of quercetin (100, 150, and 200 μM) were added to a sol-gel derived mesoporous bioactive glass. Injectable pastes based on quercetin-loaded bioactive glass, sodium alginate, and hyaluronic acid were prepared. Aggregated nanoparticles of bioactive glass and quercetin-loaded bioactive glass with mesoporous morphologies were confirmed by TEM and BET techniques. The quercetin release study was assessed in phosphate-buffered solution medium over 200 h and the obtained data were fitted by different eqs. A sustained release of quercetin was found, in which a better regression coefficient was achieved using Weibull equation. Human-derived mesenchymal stem cells were utilized to determine alkaline phosphatase activity and bone-related protein expression by western blotting and real-time PCR evaluations. Quercetin-loaded pastes increased the levels of alkaline phosphatase activity and the expression of Collagen-1, Osteopontin, Osteocalcin, and Runx2 proteins in a concentration-dependent manner. Due to the mesoporous architecture and high specific surface area of bioactive glass, the paste made of these particles and sodium alginate/hyaluronic acid macromolecules is appropriate matrix for quercetin release, resulting in promoted osteogenesis. The further in vivo studies can support the osteogenesis capacity of the quercetin-loaded paste.

Comparison between the structural characteristics and process activity of bulk and mesoporous Ni-Co-Ce/Al2O3 catalysts in the dry reforming of methane

Dry reforming of methane (DRM) is a potential way to exploit greenhouse gases and generate hydrogen. Catalyst deactivation is the biggest DRM commercialization obstacle. Lately, Ni-Co bimetallic catalysts have demonstrated improved carbon resistance over Ni-based catalysts. The aim of this research is not just to investigate the impact of Ni-Co catalysts on the DRM activity, but also to evaluate the Ni-Co alloy creation effect on the catalyst characteristics and activity. Mesoporous alumina (MA) was used as a catalyst support for Ni-Co particles in this process and its structure and activity were compared to those of bulk alumina (BA) supported catalysts. In addition, cerium was included into all of the catalysts developed as a suitable promoter for reducing the amount of deposited coke. The results obtained from the XRD and nitrogen adsorption/desorption analysis indicated the formation of a mesoporous structure and nanocrystalline morphology in the Ni-Co/MA samples, as compared to the Ni-Co/BA ones. The results showed that the bimetallic 2Ni-1Co-1Ce/MA sample had the best catalytic activity, with a CH4 conversion of 98.30 %, CO2 conversion of 96.35 %, and H2 yield of 96.30 % at 700 °C.

Metal cation and crystal lattice water molecule stabilized highly mesoporous manganese oxide network for excellent durable electrode in sodium-ion storage

Potassium birnessite is a remarkable material with a wider inter-planar spacing, which enables to accommodate more electrolytic ions to improve overall electrochemical performances. In this work, controlled synthesis of K0.46Mn2O4(H2O)1.4 (HKMO) nanosheets were interconnected mesoporous networks uniformly grown on carbon cloth (CC) via a one-step hydrothermal process. Specifically, the HKMO sample synthesized at 100 °C for 12 h (100@HKMO-12 h) exhibited a mesoporous morphology with a large specific surface area. The binder-free 100@HKMO-12 h electrode exhibits a maximum specific capacitance of 255F g−1 (323F cm−3) in 1 M NaClO4/acetonitrile electrolyte over a broad potential range of 3 V. DFT studies demonstrated the interlayer distance increased by the insertion of K+ ions into the MnO2 matrix. Bader charge analysis showed a 12.09 |e| charge difference for K-birnessite in the inter-layer region compared to the normal birnessite, supported the increase of inter-layer region in the MnO2 matrix. Significantly, the increased interlayer the distance, promoted rapid intercalation/deintercalation of Na+ ions and allowed the reversible faradic pseudocapacitance reaction to occur at a wider potential window. Moreover, the symmetric full-cell fabricated utilizing the 100@HKMO-12 h electrodes have a wide voltage of 2 V and the device delivered a maximum specific energy of 43 Wh kg−1 (28 Wh cm−3) at a minimum specific power of 556 W Kg−1 (349 W cm−3). Besides, the device showed an excellent capacitance retention of ∼94 % even after 10,000 continuous charge–discharge cycles at a current of 5 A/g, indicating it is a potential candidate for next-generation sodium energy storage devices.

Synthesis of Co/Ni-Doped mesoporous spinel ferrite microspheres for enhanced Low-Temperature SCR performance

The iron-based catalysts commonly used in the selective catalytic reduction (SCR) process cannot meet the increasingly stringent low-temperature NOx emission targets. In this study, mesoporous microspherical MFe2O4 (M=Co, Ni) spinel ferrite catalysts were synthesized by hydrothermal method and applied to the SCR of ammonia (NH3-SCR) reaction. Compared to Fe3O4, both NiFe2O4 and CoFe2O4 catalysts showed higher SCR catalytic activity at low temperature. The NiFe2O4 catalyst achieved a NO conversion of 95.5 % at 240 °C, while CoFe2O4 exhibited a high NO conversion of 97.6 % at 180 °C and a N2 selectivity of 99.6 %. Various characterization experiments revealed that the introduction of Co and Ni resulted in the formation of a specific mesoporous microsphere morphology in CoFe2O4 and NiFe2O4 catalysts, along with the generation of a large number of oxygen vacancies and acidic sites on the surface. These features facilitate the sequential adsorption and activation of NH3 and NOx species, resulting in excellent catalytic activity at low temperatures. Detailed in situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) measurements showed that on NiFe2O4 the reaction follows the Eley–Rideal (E–R) mechanism, whereas it proceeds through the Langmuir–Hinshelwood (L–H) and Eley–Rideal (E–R) mechanisms on the CoFe2O4 catalyst. This work provides a feasible strategy for enhancing the low-temperature SCR reaction over iron-based catalysts; moreover, the elucidation of the complete reaction mechanism offers a solid foundation for future improvements in denitrification catalysts.

Enhanced removal of methylene blue and procion deep red H-EXL dyes from aqueous environments by modified-bentonite: Isotherm, kinetic, and thermodynamic

This study aims to enhance local bentonite's effectiveness in removing methylene blue and procion deep red dyes from aqueous media through organic modification with cetyltrimethylammonium bromide surfactant. Raw and modified bentonites were analyzed using XRF, XRD, FTIR, BET/BJH, and DSC techniques. The modified bentonite showed a crystalline structure and mesoporous morphology with a heterogeneous surface. Optimal adsorption conditions for MB dye were 0.2 g adsorbent dose, 60 min contact time, 60 mg/L initial concentration, and pH 8, achieving a maximum sorption capacity of 6.418 mg/g. For PDR dye, optimal conditions were a 0.125 g adsorbent dose, 40 mg/L initial concentration, 30 min contact time, and acidic pH, with a maximum adsorption capacity of 8.503 mg/g. Isotherm analysis indicated the Langmuir model best fits the adsorption data, suggesting a mono-layer adsorption process. Kinetic investigations revealed that the adsorption follows a pseudo-second-order model, indicating a chemisorption mechanism. Thermodynamic results showed exothermic adsorption for MB and endothermic adsorption for PDR. This work highlights the potential of surfactant-modified bentonite as a cost-effective sorbent for treating polluted aqueous systems, effectively removing both cationic and anionic dyes.

A novel mesoporous carbon pocket with single atom Cr sites for high performance Lithium-Sulfur battery

Lithium-sulfur batteries (LSBs) are considered one of the most promising next-generation energy storage devices. However, their practical application is limited by the sluggish conversion kinetics and shuttle behavior of lithium polysulfides (LiPSs). In this work, we employ a facile salt template and micelle-mediated co-assembly strategy to synthesize atomic Cr dispersed mesoporous N-doped carbon pocket (denoted as Cr-mNC pocket). The designed Cr-mNC pocket exhibits uniform and ordered mesoporous caged morphology with a high surface area (843.5 m2/g), large pore volume (0.184 cm3 g−1), and uniform mesopore size (3.7 nm). The mesoporous structure offers a facilitated pump to promote electron/ion transportation while exposing more catalytic sites. These advantages enable the Cr-mNC pocket modified membrane to facilitate Li+ diffusion, enhance LiPSs adsorption, and accelerate electrochemical reaction kinetics for polysulfide conversion. Consequently, LSBs with Cr-mNC modified separator show a high sulfur utilization (1405 mAh g−1 at 0.2 C), a remarkable rate performance (776 mAh g−1 at 5 C), a low capacity decay rate of 0.047 % per cycle at 2 C over 1000 cycles, and even remain at 4.47 mAh cm−2 after 100 cycles with a high sulfur load of 5.0 mg cm−2.

PREPARATION AND CHARACTERIZATION OF ACTIVATED CARBON FROM DATE PALM (Phoenix dactylifera) SEEDS

In this study, agricultural waste (date seeds) were used to produce activated carbon in an oxygenated environment. The produced activated carbon was characterised. The HRSEM showed mesoporous structural morphology, which exhibited a surface area of 54.53 m2/g, pore size of 10.34 nm and pore volume of 0.1256 cc/g. The EDX spectrum revealed the presence of C and O as the major elemental compositions in the activated carbon. The FTIR spectrum indicated the presence of OH-, C=C, C=O and C-H at absorption bands of 3400, 2900, 1650, and 1300 cm-1, respectively. The diffractogram of the activated carbon revealed graphitic carbon 2 peaks of 22o and 43o which are related to (002) and (100) plane, respectively. The conversion of agricultural waste to activated carbon possessing these unique properties could serve as a promising and low-cost adsorbent for the removal of toxic pollutants from industrial wastewater.

Phosphorus-doped cobalt oxide/cobalt sulfide heterostructure for enhanced oxygen evolution

Regulating the distribution of valence charges near the Fermi level and d-band center of metal atom active sites is crucial for developing highly efficient and stable catalysts for oxygen evolution reaction (OER), yet it remains a significant challenge. In this study, we prepared phosphorus-doped Co3O4/Co9S8 catalysts with a mesoporous nanorod morphology and Mott-Schottky heterojunction. Compared to Co3O4, Co9S8 and Co3O4/Co9S8, this catalyst exhibits enhanced OER properties with an overpotential of 156 mV at 10 mA cm−2, 380 mV at 50 mA cm−2, and 450 mV at 100 mA cm−2. Moreover, when a voltage of 2.0 V vs. RHE is applied, the current density reaches 350 mA cm−2. Density functional theory (DFT) calculations reveal that the coupling of Co3O4 and Co9S8 interfaces and phosphorus doping lead to the rearrangement of d-orbital electrons of Co atoms on the crystal plane, optimizing the d-band center. Crystal orbital Hamilton population (COHP) analysis shows that the partial anti-bonding state transitions into the unoccupied region, reducing the anti-bonding state and enhancing the bonding state, thus significantly improving the adsorption for the target intermediate (*OOH), resulting in higher intrinsic activity. This study demonstrates that the pathway of doping this heterojunction with P synergistically enhances the catalytic activity of this composite for OER in water splitting electrocatalysis.

Mn-O bond Engineering Mitigating Jahn-Teller Effects of Manganese Oxide for Aqueous Zinc-ion Battery Applications

Manganese-based oxides (MNO) are commonly employed as cathodes in aqueous zinc-ion batteries (AZIBs) due to their affordability, minimal toxicity, and various valence states. However, the Jahn–Teller (J-T) effect of high-spin Mn3+ can induce Mn2+ dissolution and irreversible phase changes, significantly deteriorating the cycling life. Herein, 1D core–shell Mn3O4 with doping of heteroatoms is successfully designed through a dopamine coating and subsequent annealing strategy. Specifically, N-doping elongated the Mn-O bonds within the Mn3O4 crystal, suppressing lattice J-T distortion caused by MnO6 octahedra. This result in weakened electrostatic repulsion, contributing not only to structural stability but also facilitating the insertion of more cations. Simultaneously, N-doping carbon encapsulates Mn3O4 with an external conductive network, providing a unique mesoporous morphology and improved conductive pathways. Therefore, the optimized NC@Mn3O4 displays high capacity (420 mAh/g at 1 A/g) and superior cycle stability (90.34 % of capacity retention over 1000 cycles at 3 A/g). In addition, the charge storage of NC@Mn3O4 is the highly reversible H+/Zn2+ co-intercalation/extraction reactions, which revealed by ex-situ characterizations. This work initially proposed an effective design trend to eliminate the J-T effect, and provided assistance for the application of MNO cathode materials.

Physico-chemical characterization of feldspars for application as fluxing agents: Experimental and ab initio computational approaches

Feldspars are tectosilicates with unique composition and structural features employed to help develop the glassy phase while firing ceramic raw materials. This promotes vitrification by lowering sintering temperatures thereby making it more energy efficient and sustainable. This study examined the physico-chemical parameters of feldspars found in Marimanti, Tharaka Nithi county in Kenya with the aim of determining their fluxing capabilities. This was achieved through the use of ab-initio theoretical computations and experimental investigation into phases, morphology and thermal stability. Experimental results showed albite and anorthite mineral phases with dominant alumina and silica content, classifying it as a plagioclase type. Further experimental results revealed four predominant phases viz: Ca-feldspar, K-feldspar, Na-feldspar and quartz with mesoporous morphology and average particle sizes of 5 μm. Thermal stability studies showed a significant derived weight loss per °C in the 400–700 °C range with a peak at 497.67 °C. Three-dimensional atomistic simulations conducted on albite, anorthite and feldspar mineral phases were computed using the Cambridge Serial Total Energy Package (CASTEP) module of Material Studio software, using generalized gradient approximation (GGA) with Perde-Burke-Ernzerhof (-PBE) correction function. Accordingly, ab initio studies showed the minerals had a 3D triclinic lattice structure with predicted bulk moduli of 45.91 GPa and 88.86 GPa for albite and anorthite, respectively. In furtherance, the computed band gap energies were 2.644 eV for albite and 2.661 eV for anorthite, indicating high insulation capacity for both mineral phases. Overall, the experimental and computational results obtained were in agreement with literature on fluxing properties. Further, the outstanding properties reported indicated high quality feldspars which can be exploited sustainably for application as fluxing agents.

Adsorption behavior of Mg–Al layered double hydroxide on Pb(Ⅱ), Zn(Ⅱ), Cd(Ⅱ), and As(V) coexisting in aqueous solution

MgAl-layered double hydroxide（MgAl-LDH）was synthesized via hydrothermal method, and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption, energy dispersive spectrum (EDS). The results proved that the prepared MgAl-LDH exhibited a well-defined layered structure and mesoporous morphology with a large specific surface area, which endowed them with abundant adsorption sites and diffusion mass transfer channels for heavy metal ions. Subsequently, the MgAl-LDH was used to evaluate the adsorption efficiency for Pb(Ⅱ), Zn (Ⅱ), Cd (Ⅱ), and As(V) coexisting in aqueous solutions by batch equilibrium experiments. The results showed favorable adsorption performance of MgAl-LDH toward four coexisting ionic species, with competitive adsorption among the heavy metal ions. Under the experimental conditions, the removal rates of Pb(Ⅱ), Zn (Ⅱ), Cd (Ⅱ), and As(V) ions were 96.7%, 97.1%, 65.2%, and 98.7%, respectively, and the selective order for cation adsorption followed Pb(Ⅱ) > Zn (Ⅱ) > Cd (Ⅱ). Furthermore, the adsorption mechanisms of Pb(Ⅱ), Zn (Ⅱ), Cd (Ⅱ) and As(V) by MgAl-LDH were detailed conducted by XRD, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis, and could be ascribed to the surface complexation, precipitation and isomorphic replacement for Pb(Ⅱ), Zn (Ⅱ), Cd (Ⅱ) while surface complexation, ion exchange and electrostatic adsorption for As(V).

Safety evaluation of synthesized magnesium carbonate hydrate particles following inhalation exposure

Numerous fine particles or mist from environmental substances significantly contribute to human beings, affecting health issues for both humans and the environment by irritating the respiratory system. To achieve scarcity of information regarding exposure routes and the relationship between substance and health effects needs to be investigated more. Here, we investigated flame retardants (FRs): magnesium carbonate was synthesized, and its inhalation toxicity was examined for the first time by applying it to Sprague-Dawley rats using a mist aerosol-supplying chamber condition. The synthesized magnesium carbonate was fully physiochemically characterized, exhibiting a mesoporous sheet-like morphology, size distribution of 4.971 ± 2.363 μm, the dypingite phase, a surface area of 10.718 m² g−1, and a pore volume of 0.051 cm³ g−1. As a result of the inhalation toxicity study, the 50% lethal concentration (LC50) of magnesium carbonate was determined to be equal to or greater than 1.91 mg m−3. Microscopic examination for assessing pulmonary residue levels of magnesium carbonate reveals the presence of residues in the lungs up to 3 days post-administration. However, over time, there is a gradual decrease of pulmonary residues, and by the 14th day of administration, it is regarded that no residual presence is observable within the pulmonary system.

Shape Matters: Impact of Mesoporous Silica Nanoparticle Morphology on Anti-Tumor Efficacy.

A nanoparticle's shape is a critical determinant of its biological interactions and therapeutic effectiveness. This study investigates the influence of shape on the performance of mesoporous silica nanoparticles (MSNs) in anticancer therapy. MSNs with spherical, rod-like, and hexagonal-plate-like shapes were synthesized, with particle sizes of around 240 nm, and their other surface properties were characterized. The drug loading capacities of the three shapes were controlled to be 47.46%, 49.41%, and 46.65%, respectively. The effects of shape on the release behaviors, cellular uptake mechanisms, and pharmacological behaviors of MSNs were systematically investigated. Through a series of in vitro studies using 4T1 cells and in vivo evaluations in 4T1 tumor-bearing mice, the release kinetics, cellular behaviors, pharmacological effects, circulation profiles, and therapeutic efficacy of MSNs were comprehensively assessed. Notably, hexagonal-plate-shaped MSNs loaded with PTX exhibited a prolonged circulation time (t1/2 = 13.59 ± 0.96 h), which was approximately 1.3 times that of spherical MSNs (t1/2 = 10.16 ± 0.38 h) and 1.5 times that of rod-shaped MSNs (t1/2 = 8.76 ± 1.37 h). This research underscores the significance of nanoparticles' shapes in dictating their biological interactions and therapeutic outcomes, providing valuable insights for the rational design of targeted drug delivery systems in cancer therapy.

Mesoporous Nitrogen-Doped Holey Reduced Graphene Oxide: Preparation, Purification, and Application for Metal-Free Electrochemical Sensing of Dopamine.

Holey graphenic nanomaterials with porosity within the basal plane attract significant interest. It is observed that the perforation of graphene can enhance the specific surface area of the nanosheet, ensuring effective wetting and penetration of electrolytes to the electrode surface, facilitating rapid charge transfer, and boosting the electrocatalytic efficacy of the transducers. This study reports the first example of nitrogen-doped holey reduced graphene oxide with a mesoporous morphology of the graphene basal plane (N-MHG). It is shown that N-MHG can be synthesized through a one-step hydrothermal treatment of GO using NH3 and H2O2. A straightforward procedure for the purification of N-MHG has also been developed. AFM, TEM, and Raman analyses have revealed that N-MHG possesses a highly mesoporous network structure with a pore size ranging from 10 to 50 nm. X-ray photoelectron spectroscopy data have indicated a partial reduction of the graphene oxide sheets during the etching process but also show a 3-5 times higher content of C═O and O-C═O fragments compared to rGO. This could account for the remarkable stability of the N-MHG aqueous suspension. An electrochemical sensor for dopamine analysis is assembled on a glassy carbon electrode with N-MHG/Nafion membrane and characterized by cyclic voltammetry and electrochemical impedance spectroscopy.

Production and characterization of activated carbon foams with various activation agents for electrochemical double layer capacitors (EDLCs) applications

Sucrose-based activated carbons were obtained by carbon foams with sugar and cobalt (II) nitrate as precursors, followed by using different chemical activation agents. The effect of Co(NO3)2 concentration, the carbonization temperature and the activation agent on the surface chemistry, porosity were investigated. Textural characterization and electrochemical tests were performed on the activated carbon samples (CF). The results showed that the activated carbon produced by H2SO4 and KOH at 800°C had a surface area of 691 m2/g and 1125 m2/g, 89% and 80% of the sample pore structure was microporous, and specific capacitance of 8.4 F/g and 162.2 F/g at a constant current density of 250 mA/g, respectively. K2CO3-activated carbon had 918 m2/g surface area and 63% of the sample pore structure with microporous and 1.4 F/g specific capacitance, H3PO4-activated carbon and ZnCl2-activated carbon had 1833 m2/g and 1597 m2/g surface area, 53% mesoporous and 50% mesoporous, 222.4 F/g and 149.9 F/g specific capacitance respectively. The most promosing result was observed in the electrochemical storage behavior of the carbon materials with hierarchical pore structure activated with H3PO4 is associated with increasing defect zones at the edges of micro- and mesoporous morphology, resulting in a higher surface area and increased conductivity of the material.

The Synthesis and Reactivity of Mesoporous and Surface-Rough Vinyl-Containing ORMOSIL Nanoparticles

Silica nanoparticles synthesized solely from organosilanes naturally possess a greater number of organic functionalities than silica nanoparticles surface-modified with organosilanes. We report the synthesis of organically modified silica (ORMOSIL) nanoparticles with a mesoporous and surface-rough morphology and with a high surface area, made solely from vinyltrimethoxy silane. We chemically modified these vinyl silica nanoparticles using bromination and hydroboration, and demonstrated the high accessibility and reactivity of the vinyl groups with an ~85% conversion of the functional groups for the bromination of both particle types, a ~60% conversion of the functional groups for the hydroboration of surface-rough particles and a 90% conversion of the functional groups for the hydroboration of mesoporous particles. We determined that the mesoporous vinyl silica nanoparticles, while having a surface area that lies between the non-porous and surface-rough vinyl silica nanoparticles, provide the greatest accessibility to the vinyl groups for boronation and allow for the incorporating of up to 3.1 × 106 B atoms per particle, making the resulting materials attractive for boron neutron capture therapy.

Synthesis of Sustainable Lignin Precursors for Hierarchical Porous Carbons and Their Efficient Performance in Energy Storage Applications.

Lignin-derived porous carbons have great potential for energy storage applications. However, their traditional synthesis requires highly corrosive activating agents in order to produce porous structures. In this work, an environmentally friendly and unique method has been developed for preparing lignin-based 3D spherical porous carbons (LSPCs). Dropwise injection of a lignin solution containing PVA sacrificial templates into liquid nitrogen produces tiny spheres that are lyophilized and carbonized to produce LSPCs. Most of the synthesized samples possess excellent specific surface areas (426.6-790.5 m2/g) along with hierarchical micro- and mesoporous morphologies. When tested in supercapacitor applications, LSPC-28 demonstrates a superior specific capacitance of 102.3 F/g at 0.5 A/g, excellent rate capability with 70.3% capacitance retention at 20 A/g, and a commendable energy density of 2.1 Wh/kg at 250 W/kg. These materials (LSPC-46) also show promising performance as an anode material in sodium-ion batteries with high reversible capacity (110 mAh g-1 at 100 mA g-1), high Coulombic efficiency, and excellent cycling stability. This novel and green technique is anticipated to facilitate the scalability of lignin-based porous carbons and open a range of research opportunities for energy storage applications.