Mesoporous Nanocomposites Research Articles

Mesoporous nanocomposites based on CeO2 and MgO: preparation, structure and photocatalytic activity

AbstractBACKGROUNDSelf‐propagating high‐temperature synthesis was used to create mesoporous CeO2 and MgO powders as well as nanocomposites based on them for efficient degradation of organic dyes.RESULTSIt has been investigated how magnesium oxide and cerium oxide interact to affect the crystal structure, morphology and microstructure of the materials produced. It was assumed that CeO2 forms on the surface of MgO while the material's developed surface is preserved. The values of the specific surface area and average pore diameter of the studied samples depend on the composition and vary in the ranges of 16–41 m2 g−1 and 11.919 nm, respectively.CONCLUSIONIt has been established that the sizes of CeO2 crystallites in the composition of nanocomposites change insignificantly and range from 6.5 to 7.4 nm. The photocatalytic activity of the studied samples is at least two times higher compared to analogs. The samples MgO–CeO2 (30 mol%) and MgO–CeO2 (50 mol%) showed the maximum photodegradation efficiency of acid telon blue and direct bright blue dyes at levels of 98.5% and 92.5%, respectively. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).

A sustainable route for production of graphene oxide-contained nanostructured carbons from rice husk waste and its application in wastewater treatment

Agricultural biomass, such as rice husk (RH), is a renewable source of bioenergy. However, a large amount of RH ash (RHA) is generated after the thermal conversion of RH. The main component of RHA is silica (>85 wt%). This study used recyclable RHA as a mesoporous SBA-15 template source. Next, ordered mesoporous carbon/ graphene oxide (RH-CMK-3/GO) composites were synthesized through the direct carbonization of GO, sucrose, and an SBA-15 template. Experimental data demonstrated that GO was successfully conjugated on the surface of CMK-3. The RH-CMK-3/GO exhibited a highly ordered mesostructure, which was not affected by the incorporation of GO. Compared with bare RH-CMK-3, the RH-CMK-3/GO had an enhanced surface area and pore volume. The composite exhibited a highest pore volume of 1.143 cm 3/g, a surface area of 1138 m2/g, and a pore diameter of 3.68 nm. The RH-CMK-3/GO revealed a higher ability for the adsorption of rhodamine B (RhB) than did the SBA-15, SBA-15/GO, and pure CMK-3 materials. The removal of RhB increased with increases in the composite dosage, solution pH and temperature, and carbonization temperature and time and a decrease in the initial RhB concentration. Moreover, the RH-CMK-3/GO exhibited a highest removal efficiency of 100%. The thermodynamics, kinetics, and isotherm adsorption data for the RH-CMK-3/GO composite exhibited satisfactory fitting for the endothermic, pseudo-second-order, and Langmuir models, respectively. Moreover, the composite exhibited good reusability. These results suggest that RHA can be effective for the fabrication of valuable mesoporous carbon nanocomposites and the elimination of organic contaminants from wastewater.

Fabrication of Polyaniline‐Supported MnO2 Nanocomposite for Removal of Water Pollutant: Kinetic and Isotherm Studies

AbstractIn the present work, we have successfully developed polyaniline supported manganese dioxide (PANI/MnO2) nanocomposite using a facile and inexpensive approach under mild and green conditions by the PANI nanofiber sacrificial oxidation induced reductive conversion of KMnO4 as MnO2. The developed PANI/MnO2 adsorbent material was efficiently utilized for the removal of an organic dye Toluidine Blue (TB) from the aqueous samples.The fabricated adsorbent material was composed of the microstructures that possess grainy and fibrous morphology, and highly uneven surface textures. The FTIR, EDS, and XPS results show the presence of Mn, O, C, and N elements in the nanocomposite. Additionally, from XPS data the survival of the Mn+4 valance state of manganese was recognized. The nano‐thread deposited nano‐fibrous mesoporous nanocomposite holds a high BET surface area (168.096 m2 g−1), and pore volume (0.4428 cm3 g−1).The batch adsorption equilibrium studies showed that 97.51 % of the TB dye was eliminated in 70 min of sorption equilibrium at neutral pH with 92 mg/g of adsorption capacity. The kinetics of the adsorption process is finely portrayed by the pseudo‐second‐order (PSO) kinetic model and the adsorption mechanism is found to be concurrently controlled by intraparticle (IP) and film diffusion (FD) processes. The adsorption isotherm analysis studies revealed that the adsorption of TB dye over the developed PANI/MnO2 adsorbent material occurred with coverage of energetically equivalent binding sites by monolayer formation as substantiated by Langmuir isotherm.

Magnetic Dendritic Polymer Nanospheres for High-Performance Separation of Histidine-Rich Proteins.

Magnetic nanospheres are becoming a promising platform for a wide range of applications in pharmacy, life science, and immunodiagnostics due to their high surface area, ease of synthesis and manipulation, fast separation, good biocompatibility, and recyclable performance. In this work, an innovative and efficient method is developed by in situ reducing and growing Ni(OH)2 for the preparation of dendritic mesoporous nanocomposites of silica@Fe3O4/tannic acid@nickel hydroxide (dSiO2@Fe3O4/TA@Ni(OH)2). The flower-like nanospheres have good magnetic response, large surface area, and high histidine-rich protein (His-protein) purification performance. The dSiO2@Fe3O4/TA@Ni(OH)2 nanospheres were synthesized on the basis of a φ(NaSal/CTAB) of 1/1 and a mass of ferrous chloride tetrahydrate of 0.3 g, resulting in a saturation magnetization value of 48.21 emu/g, which means it can be collected within ∼1 min using a magnetic stand. Also, the BET test showed that the surface area is 92.47 m2/g and the pore size is ∼3.9 nm for dSiO2@Fe3O4/TA@Ni(OH)2 nanocomposites. Notably, the nickel hydroxide with unique flower-like structural features enables the combination of a large number of Ni2+ ions and His-proteins for high performance. The isolation and purification experiments of the synthesized dSiO2@Fe3O4/TA@Ni(OH)2 were performed by separating His-proteins from a matrix composed of bovine hemoglobin (BHb), bovine serum albumin (BSA), and lysozyme (LYZ). The result showed that the nanospheres have a high combination capacity of ∼1880 mg/g in a rapid equilibrium time of 20 min, which was selective for the adsorption of BHb. In addition, the stability and recyclability of BHb are 80% after seven cycles. Furthermore, the nanospheres were also used to isolate His-proteins from fetal bovine serum, proving its utility. Therefore, the strategy of separating and purifying His-proteins using dSiO2@Fe3O4/TA@Ni(OH)2 nanospheres is promising for practical applications.

Enhancing electrochemical performance in aqueous rechargeable Zn-ion batteries through bimetallic oxides of manganese and cobalt as electrode

The capacity of Co3O4//Zn batteries is decreased by the volume change of Co3O4 cathode in practical application, so its advantages are not fully utilized. To improve the capacity of Co3O4//Zn battery, a cathode of Mn-doped Co3O4 based on carbon cloth in aqueous zinc-ion battery was successfully prepared by one-step hydrothermal. Compared to existing preparation processes, greatly reducing preparation time and cost, and the Mn-doped Co3O4 cathode had a unique mesoporous microsphere structure. The battery in aqueous electrolyte had a high charge/discharge voltage of 2.2 V, a high specific capacity of 279.3 mAh/g at 1 A/g, outstanding rate capability, a high energy density of 863.15 Wh/kg, a high power of 1327.9W/Kg and superior cycle stability of 97% capacity retention over 1000 cycles at 5 A/g. The improvement in electrode material provided a new idea for preparing new mesoporous Co3O4 nanocomposites.

Synthesis of calcium carbonate-loaded mesoporous SBA-15 nanocomposites for removal of phosphate from solution.

Removal of phosphate from water is very crucial for protecting the ecological environment since massive phosphorus fertilizers have been widely used and caused serious water deterioration. Thus, we fabricated a series of calcium carbonate-loaded mesoporous SBA-15 nanocomposites with different Ca:Si molar ratio (CaAS-x) as phosphorus adsorbents via a simple wet-impregnation method. The multiply approaches including X-ray diffraction (XRD), N2 physisorption, thermogravimetric mass spectrometry (TG-MS), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT-IR) were used to characterize the structure, morphology, and composition of mesoporous CaAS-x nanocomposites. The phosphate adsorption efficiency of the CaAS-x nanocomposites was studied through adsorption and desorption batch tests. Results showed that the increases of Ca:Si molar ratio (rCa:Si) improved the phosphate removal capacity of CaAS nanocomposites, especially CaAS with the optimum synthesis molar ratio of Ca:Si as 0.55 showed the high adsorption capacity of 92.0 mg·g-1 to high concentration of phosphate (> 200 mg·L-1). Note that the CaAS-0.55 had a fast exponentially increased adsorption capacity with increasing the phosphate concentration and correspondingly showed a much faster phosphate removal rate than pristine CaCO3. Apparently, mesoporous structure of SBA-15 contributed to high disperse of CaCO3 nanoparticles leading to the monolayer chemical adsorption complexation formation of phosphate calcium (i.e., =SPO4Ca, =CaHPO4-, and =CaPO4Ca0). Therefore, mesoporous CaAS-0.55 nanocomposite is an environmental-friendly adsorbent for effective removal of high concentration of phosphate in neutral contaminated wastewater.

Synthesis of multifunctional superparamagnetic mesoporous ZnMnFe2O4@Fe–CaSiO3 core-shell for medical applications

Herein, we report the synthesis of a mesoporous calcium silicate superparamagnetic nanoparticle as ZnMnFe2O4@Fe–CaSiO3 core-shell. This core-shell nanocomposite reveals excellent properties such as mesoporous nanocomposite, superparamagnetic at room temperature, low toxicity, large surface area, tunable pore size, and easy surface manipulation. The core nanocomposite (ZnMnFe2O4) is synthesized by the hydrothermal method, which shows a superparamagnetic behavior with an excellent saturation magnetization of 52.09 emu/g. The core-shell structure is prepared by a micellar-assisted sol-gel method, which uses a copolymer to create pores in the structure of CaSiO3. To improve the magnetic properties of the core-shell structure, different percent of Fe ions (0%, 5%, and 10%) are doped onto the calcium silicate structure; as for 10% Fe, i.e., ZnMnFe2O4@Fe10–CaSiO3, saturation magnetization and coercive magnetic field are 34.543 emu/g and 1Oe, respectively. In this configuration of nanocomposite, the pore volume and superparamagnetic property increase simultaneously. In addition, the core-shell mesoporous ZnMnFe2O4@Fe–CaSiO3 nanocomposite reveals comparable mesoporous channels (3.4–6 nm), while the amorphous structure of CaSiO3 has not been changed. These core-shell mesoporous superparamagnetic nanocomposites are evaluated in terms of drug loading and release using epirubicin (EPI) as a model drug. It is found that the increase of iron ions improves the capacity to stabilize the pH environment. Additionally, the mesoporous Fe–CaSiO3 nanostructures demonstrate a sustained drug release property that could be used in local drug delivery therapy. Therefore, these mesoporous superparamagnetic nanostructures would be a promising multifunctional platform for local drug delivery, magnetic resonance imaging, magnetic hyperthermia, and bone tissue regeneration.

Mesoporous MgFe2O4@HaP@APTES nanocomposite as scaffold for α-glucosidase coupling

Many natural products contain inhibitory ligands for α-glucosidase, and in recent years, many bioanalytical screening techniques have been developed to help identify and characterize these small molecules from plant extracts. Yet, except Fe3O4 magnetic beads, few other nanoparticles have been described as α-glucosidase immobilization scaffolds for bioanalytical assay development. In this study, we describe the coupling of α-glucosidase to an amino-functionalized magnesium ferrite and hydroxyapatite mesoporous nanocomposite (MgFe2O4@HaP@APTES). The bare nanocomposite was synthesized through the coprecipitation method in aqueous solution, and its structure was investigated by X-ray diffraction and FT-IR, white its textural and magnetic properties were analyzed by BET and VSM analyses, respectively. Amino-functionalization was performed using APTES, and α-glucosidase coupling was achieved through glutaraldehyde crosslinking. We demonstrate that both enzyme activity and magnetic properties are preserved after coupling, suggesting that the nanocomposite system is suitable for further inclusion into bioanalytical platforms for enzyme inhibitor screening.

CoFe2O4 decorated graphene/C18-functionalized mesoporous silica nanocomposites prepared for magnetic enrichment and electrochemical detection of promethazine in beef

Promethazine (PHZ) is used as a sedative in veterinary medicine, and its residue can threaten the health of human. The electrochemical detection of PHZ is suitable method for application in the field. However, the traditional electroanalysis is difficult to perform directly in meat samples due to matrix interference. This work integrates magnetic solid-phase extraction and differential pulse voltammetry for highly sensitive and selective determination of PHZ in beef and beef liver for the first time. CoFe2O4/graphene coated with C18-functionalized mesoporous silica (MG@mSiO2-C18) is synthesized as dispersed magnetic adsorbent to extract PHZ. Magnetic glassy carbon electrode modified with nitrogen-doped hollow carbon microspheres (HCM) attracts the MG@mSiO2-C18 with PHZ, and directly detects the PHZ without elution procedure. MG@mSiO2-C18 can separate PHZ to avoid the interference of impurities on following detection, and also concentrate PHZ on magnetic electrode. Additionally, the electrode modification with HCM can amplify the electrochemical signal of PHZ. Finally, the integrated PHZ determination method exhibits a wide linear range from 0.08 µmol/L to 300 µmol/L with a low limit of detection of 9.8 nmol/L. The beef sample analysis presents excellent recovery, demonstrating that this protocol is promising for the rapid and onsite detection of PHZ in real meat samples

Porous ZnS/MXene Ti3C2 nanocomposite with a terrific photocatalytic ability for tetracycline hydrochloride degradation

Porous ZnS/MXene Ti3C2 nanocomposite was synthesized by one-step hydrothermal method. MXene Ti3C2 with a unique layered structure was used as cocatalyst. ZnS/MXene Ti3C2 nanocomposite was utilized for photocatalytic degradation of tetracycline hydrochloride (TCH). The photodegradation efficiency of TCH were 96% during 60 min under simulated sunlight irradiation. The opened 2D space of MXene Ti3C2 was suitable for ZnS nanoparticles dispersion, which obtained a mesoporous nanocomposite with plenty of heterostructure interfaces. At the same time, the good electron transfer efficiency of MXene Ti3C2 could also provide the high-speed channel through the numerous intimate heterostructure interfaces. Meanwhile, ZnS/MXene Ti3C2 nanocomposite could still maintain a good stability after three cycles. It was significant that ZnS/MXene Ti3C2 nanocomposite achieved an excellent separation efficiency of photogenerated carriers via constructing heterojunction. It proved that porous ZnS/MXene Ti3C2 nanocomposite as a mesoporous superior photocatalyst was an effective and potential photocatalyst for antibiotic degradation.

Promoted visible-light-driven oxidative desulfurization of thiophene over mesoporous PdO-incorporated BaSnO3 nanocomposites

An emerging method for removing sulfur-containing materials like thiophene, known as photocatalytic oxidative desulfurization, utilizes moderate temperatures and pressures without the use of H2 gas, unlike hydrodesulfurization. Here, we used a hydrothermal technique to produce Barium stannate nanoparticles (BaSnO3 NPs). A PdO/BaSnO3 photocatalyst was then fabricated by adding small amounts (0.5–2.0% wt) of PdO to mesoporous BaSnO3. After 150 min under illumination, the developed PdO/BaSnO3 photocatalyst showed complete thiophene photooxidative desulfurization and had excellent recyclability. The designed nanocomposite containing 2.0 wt% of PdO, displayed improved absorption of visible light with a bandgap reduction from 2.98 to 2.21 eV. Photoluminescence and photocurrent data of the developed photocatalysts demonstrated that the recombination of the photogenerated charge carriers was also whittled down. According to kinetic studies, the PdO content and the photocatalyst dose had a significant impact on the reaction rate which follows the pseudo-first-order model. Additionally, the mechanism of photooxidation of thiophene was discussed. This research will pave the way for the wide use of perovskite oxide photocatalysts to oxidize sulfur-containing materials under visible illumination.

Synergic fabrication of hybrid nanocapsules gold-organosilica for MRI-guided photothermal-enhanced synergistic effect chemodynamic lung cancer therapy

In contrast to the typical template-based multistep approach for constructing multi-functional mesoporous hollow silica nanocomposites (MHSN), a simple and template-free fabricate system has been developed to develop versatile mesoporous hollow silica nanocapsules (OSNs) encompassing together isopentyl acetate (IsA) solution and AuNPs. This new material has tiny and homogeneous particle sizes (∼82 nm), a large surface area (535 m2 g−1), and remarkable colloidal durability in water. The oil-phase IsA with high volatility and a low boiling point (142 °C) is critical in building bulky hollow cavities from structural strategy. It allows the IsA@OSNs to become an effective development mediator in the ablation of high-intensity focused ultrasound (HIFU) treatment. Furthermore, the distinctive satellite-like dispersion of Gold (AuNPs) on the silica shell provided IsA@OSNs with outstanding magnetic resonance imaging (MRI) contrasts in A549 lung cells in vitro and in vivo. Furthermore, such unique theranostics agents have excellent systemic toxicity, which promises well for promising clinical use in MRI-piloted HIFU treatment.

Optimized extraction of mesoporous nanocomposites from spent Li-ion batteries and their use to construct high-performance supercapacitor devices with ultra-high stability

Lithium-ion batteries (LIBs) are one class of the most significant energy storage devices used nowadays. However, a huge number of spent batteries bring harmful resource waste and environmental hazards as LIBs are mainly composed of heavy metals and organic electrolytes. Consequently, recycling spent LIBs has become a hot topic lately, where researchers are actively working to develop a plethora of methods to extract valuable metals and components. In this study, mesoporous Li–Ni–Mn–Co oxide nanoparticles have been successfully extracted from spent Li-ion batteries using a simple microwave/precipitation method. The as-extracted Li–Ni–Mn–Co oxides were used to construct functional supercapacitor devices. However, the as-extracted oxides showed poor stability and low conductivity. To enhance their cycling stability and conductivity, fullerene (C76) is used as a carbon additive to form Li–Ni–Mn–Co oxide/C76 nanocomposite materials. The morphological, structural, and compositional analyses of those composites were performed using FESEM, HRTEM, XRD, and XPS techniques. The Li–Ni–Mn–Co oxide/C76 nanocomposites exhibit higher conductivity and wettability with an enhanced gravimetric capacitance of ∼357 Fg-1 at 1.0 Ag-1. The asymmetric supercapacitor devices deliver specific energy as high as ∼10 Wh/kg at a specific power of ∼800 W/kg with a superior retention rate of ∼115% after 20,000 cycles with ∼100% Coulombic efficiency.

Regioselective Surface Assembly of Mesoporous Carbon on Zeolites Creating Anisotropic Wettability for Biphasic Interface Catalysis

The anisotropic surface functionalization of microporous zeolites with mesoporous materials into hierarchically porous heterostructures with distinctive physical and chemical properties is expected to significantly extend their applicability to catalysis. However, the precise control of the surface chemistry of zeolite crystals through site-specific interconnection with mesoporous materials remains a grand challenge. Here, we report a regioselective surface assembly strategy for the region-specific growth of mesoporous polymer/carbon on zeolite nanocrystals. The approach enables controllable regioselective surface deposition of mesoporous polydopamine on the edges, curved surfaces, or/and flat surfaces of the silicalite-1 nanocrystals into exotic hierarchical nanostructures with diverse surface geometries. Upon carbonization, their derived heterostructures with anisotropic surface wettability show amphiphilic properties. As a proof of concept, Pt nanoparticle-encapsulated silicalite-1/mesoporous carbon nanocomposites are tested to be interface-active for forming Pickering emulsions. Significantly, the catalysts show superior catalytic performance in shape-selective hydrogenation of various nitroarenes in a series of biphasic tandem catalytic reactions, giving ∼100% yield of corresponding amine products. The results pave a path toward rational construction of high levels of surface structural complexity in hierarchically porous heterostructures for specific physical and chemical characteristics in diverse applications.

Cerium and carbon-sulfur codoped mesoporous TiO2 nanocomposites for boosting visible light photocatalytic activity

Ce and C–S codoped mesoporous TiO2 nanocomposites were synthesized via a sol-gel method integrated with an evaporation-induced self-assembly approach. The basic physicochemical characteristics of the synthetic samples were analyzed via a series of characterization techniques. The results reveal that C–S and Ce codoping on mesoporous TiO2 enhances the photocatalytic activity owing to the synergistic effect caused by narrowing the band gap, enhancing adsorption, trapping and transferring the excited e–/h+ pairs and suppressing the recombination of e–/h+ pairs. Furthermore, the obtained C,S–TiO2/CeO2 materials exhibit large specific surface areas and numerous pores which not only effectively improve the adsorption-enrichment capability, but also supply multi-dimensional mass and electron transfer channels. The photodegradation efficiency of RhB by C,S–TiO2/CeO2 within 40 min is nearly 100%, and its degradation efficiency is 6.63 times that of undoped TiO2. Recycling experiments show that mesoporous C,S–TiO2/CeO2 shows excellent recoverability and stability. Furthermore, by trapping experiments, •O2–, h+ and •OH are the predominant active species and a possible reaction mechanism is proposed.

Matrix Solid-Phase Extraction of Nine Pesticide Residues from Vegetables Based on Mesoporous Carbon via an Alternative Sample Preparation Approach

In this work, an n-octadecylamine functionalized mesoporous carbon nanocomposite (ODA-MPC) was synthesized, and its novel application was demonstrated by utilizing it as a sorbent in matrix solid-phase dispersion (MSPD) of nine pesticide residues identified by gas chromatography-mass spectrometer. Here, the protection of the sorbent by the mesoporous fiber membrane enabled it to process complex aqueous matrices and made it advantageous to be used in MSPD. The results confirmed the excellent ability of ODA-MPC to remove matrix interferences and reduce matrix effects compared to the traditional solid phase extraction. In particular, the recoveries were 85.0–95.8% (n = 3) with relative standard deviations less than 5%. Additionally, nine pesticide residues in vegetables and fruit were satisfactorily extracted and detected.

Synergic fabrication of folic acid-targeted hyperbranched polymer (HBP)-modified pH-response drug delivery system for the treatment of breast cancer

As vectors for anticancer drug delivery, mesoporous silica nanocomposites (MSN) incorporated bicalutamide (BLT) featuring folic acid (FA) (termed as COOH-MSNs-HBP@BLT/FA) have been effectively achieved due to their ability to pH stimulation response and targeting. Systematic characterization investigations were conducted to determine the chemical composition and physical characteristics of these NPs. Through carboxy alteration, their drug loading capacity was dramatically increased (268.60 %), and they displayed pH-responsive drug release patterns. Additionally, the cytotoxicity of the as-synthesized NPs was tested in MDA-MB-231 and MCF-7 cells in vitro. After 24-h of treatment with BLT, COOH-MSNs, COOH-MSNs@BLT, COOH-MSNs-HBP@BLT/FA, MCF-7, and MDA-MB-231 cells exhibited distinct morphological alterations, and reddish orange apoptotic bodies were detected using acridine orange and ethidium bromide (AO and EB) double staining. Nuclear alterations such as chromatin condensation/fragmentation were detected by Hoechst 33342 staining techniques. The Annexin V-FITC/PI was used to examine the apoptosis mechanism of the cells. These results prove that apoptosis induction is responsible for the antiproliferative effects of BLT, COOH-MSNs, COOH-MSNs@BLT, and COOH-MSNs-HBP@BLT/FA in MCF-7 and MDA-MB-231cells. We conclude that COOH-MSNs-HBP@BLT/FA has the potential as a drug delivery method for breast cancer treatment.

An eco-friendly and energy-efficient protocol for the Heck reaction under solar radiation catalyzed by rice husk silica‐anchored cinchonine.Pd nanocomposite

An environmentally friendly and energy-efficient method for the carbon–carbon bond formation via cross-coupling Heck reaction using rice husk silica-anchored cinchonine.Pd nanocomposite as a heterogeneous catalyst under concentrated solar radiation is being reported. In this investigation, first, silica nanoparticles were synthesized using rice husks as available agricultural bioresources. Then, the surface of nano silica was modified by grafting (3-mercaptopropyl) trimethoxysilane, and after that, thiol-ene free radical reaction of its SH groups with alkene function of cinchonine by azobisisobutylonitrile initiator. Finally, the target nanocomposite, nano SiO2-S-Cin.Pd, was created via loading palladium nanoparticles into the mesoporous nanocomposite by its reaction by palladium acetate, followed by ethanol reduction. The structure and morphology of the nano SiO2-S-Cin.Pd nanocomposite was characterized using Fourier transform infrared spectra, X-ray diffraction patterns, energy-dispersive X-ray spectroscopy, and transmission electron microscopy. The catalytic ability of this nanocomposite was investigated in the arylation of olefins in both concentrated solar radiation and conventional thermal conditions. A comparison of the conventional and CSR methods for C–C bond formation in PEG, showed that the CSR approach is a better alternative route with a high energy-saving strategy. The nanocatalyst is easily removed from the mixture and has been tested on several runs without a loss of catalytic activity. The heterogeneity of the nano SiO2-S-Cin.Pd catalyst was confirmed by hot filtration test. This method has the advantages of simple methodology, easy work-up, high yields, short reaction times, and greener conditions. In addition to convenience, this technology improves product purity and offers economic and environmental benefits.

Mesoporous silica-encapsulated Co-doped ceria nanodots with enhanced peroxidase-like activity enable intensive and long-lasting chemiluminescence for glutathione detection

Chemiluminescence (CL) assay has been considered as a sensitive method for quantitative detection of glutathione (GSH), a significant regulatory metabolite in cells. However, most reported CL assays present flash-type CL emission with limited detection accuracy and repeatability. Herein, an intensive and long-lasting glow-type CL system was proposed based on a novel bimetallic Co-doped ceria mesoporous nanocomposite (Co-ceria@MSN), which was prepared by in-situ growth of sub-3 nm ultrasmall Co-ceria nanodots within the pore channels of mesoporous silica nanospheres (MSN). Attributing to the confinement effect of MSN and the superior peroxidase-like catalytic activity of Co-ceria nanodots, this nanocomposite could function as a nanozyme to catalyze luminol/H2O2 CL reaction, producing a robust and long-lasting CL emission with a long plateau for over 1.2 h at physiological pH. Surprisingly, both the CL intensity and duration time were found to exist a strong dependence on GSH concentration. Accordingly, the proposed glow-type CL platform was further applied for GSH determination with a limit of detection down to 10 nM. This strategy was successfully utilized for quantitative evaluation of cellular GSH levels, indicating its broad prospects in clinical diagnosis.

Amine-Functionalized Natural Rubber/Mesostructured Silica Nanocomposites for Adsorptive Removal of Clofibric Acid in Aqueous Phase

This study is the first report on the synthesis, characterization and application of amine-functionalized mesoporous nanocomposites based on natural rubber (NR) and wormhole-like mesostructured silica (WMS). In comparison with amine-functionalized WMS (WMS-NH2), a series of NR/WMS-NH2 composites were synthesized via an in situ sol-gel method in which the organo-amine group was grafted onto the nanocomposite surface via co-condensation with 3-aminopropyltrimethoxysilane (APS) as the amine-functional group precursor. The NR/WMS-NH2 materials had a high specific surface area (115-492 m2 g-1) and total pore volume (0.14-1.34 cm3 g-1) with uniform wormhole-like mesoporous frameworks. The amine concentration of NR/WMS-NH2 (0.43-1.84 mmol g-1) was increased with an increase in the APS concentration, corresponding to high levels of functionalization with the amine groups of 53-84%. The H2O adsorption-desorption measurement revealed that NR/WMS-NH2 possessed higher hydrophobicity than WMS-NH2. The removal of clofibric acid (CFA), a xenobiotic metabolite of the lipid-lowering drug clofibrate, from the aqueous solution using WMS-NH2 and NR/WMS-NH2 materials was investigated using a batch adsorption experiment. The adsorption was a chemical process in which the pseudo-second order kinetic model expressed the sorption kinetic data better than the pseudo first-order and Ritchie-second kinetic order model. In addition, the CFA adsorption sorption equilibrium data of the NR/WMS-NH2 materials were fitted to the Langmuir isotherm model. The NR/WMS-NH2 with 5% amine loading had the highest CFA adsorption capacity (6.29 mg g-1).