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14 pages, 7125 KiB

Open AccessArticle

Ultraporous Amine-Functionalized Organosilicas: Tuning Morphology and Surface Chemistry for Adsorption Applications

by Marlena Bytniewska, Kacper Latusek, Maria Powęzka, Marcin Kuśmierz, Oliwia Kapusta and Mariusz Barczak

Molecules 2025, 30(14), 2990; https://doi.org/10.3390/molecules30142990 - 16 Jul 2025

Viewed by 272

Abstract

Highly porous organosilicas were synthesized via direct co-condensation of two monomers, bis (triethoxysilyl) benzene and aminopropyltriethoxysilane, by adjusting the time between consecutive additions of the monomers and the ageing time of the as-obtained samples. The resulting organosilicas exhibited high porosities, with total pore [...] Read more.

Highly porous organosilicas were synthesized via direct co-condensation of two monomers, bis (triethoxysilyl) benzene and aminopropyltriethoxysilane, by adjusting the time between consecutive additions of the monomers and the ageing time of the as-obtained samples. The resulting organosilicas exhibited high porosities, with total pore volumes exceeding 2.2 cm³/g. Alongside detailed insights into the morphology, structure, and surface chemistry via a broad spectrum of various instrumental techniques, the obtained ultraporous amine-functionalized organosilicas were tested as adsorbents of diclofenac sodium, chosen here as a model drug. The results revealed remarkable differences in the physicochemical properties and adsorption efficiencies among the obtained samples, confirming that the time gap between the addition of the monomers and ageing time can be used to tune the morphological, structural, and chemical features of the obtained organosilicas and, as a consequence, their sorption efficiencies. Full article

(This article belongs to the Special Issue Design and Synthesis of Novel Adsorbents for Pollutant Removal, 2nd Edition)

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14 pages, 5938 KiB

Open AccessArticle

Facile Synthesis of Functional Mesoporous Organosilica Nanospheres and Adsorption Properties Towards Pb(II) Ions

by Liping Deng, Shichun Gu, Ruyi Wang, Yapeng He, Hairong Dong and Xue Wang

Nanomaterials 2025, 15(2), 136; https://doi.org/10.3390/nano15020136 - 17 Jan 2025

Cited by 1 | Viewed by 856

Abstract

We successfully synthesize monodisperse sulfhydryl-modified mesoporous organosilica nanospheres (MONs-SH) via one-step hydrolytic condensation, where cetyltrimethylammonium chloride and dodecyl sulfobetaine are employed as dual-template agents with (3-mercaptopropyl)triethoxysilane and 1,2-bis(triethoxysilyl)ethane as the precursors and concentrated ammonia as the alkaline catalyst. The prepared MONs-SHs deliver a [...] Read more.

We successfully synthesize monodisperse sulfhydryl-modified mesoporous organosilica nanospheres (MONs-SH) via one-step hydrolytic condensation, where cetyltrimethylammonium chloride and dodecyl sulfobetaine are employed as dual-template agents with (3-mercaptopropyl)triethoxysilane and 1,2-bis(triethoxysilyl)ethane as the precursors and concentrated ammonia as the alkaline catalyst. The prepared MONs-SHs deliver a large specific surface area (729.15 m² g⁻¹), excellent monodispersity, and homogeneous particle size. The introduction of ethanol into the reaction systems could expand the particle size of the synthesized MONs-SH materials from 18 to 182 nm. Moreover, the successful modification of -SH groups endowed MONs-SHs with an excellent adsorption capacity (297.12 mg g⁻¹) for Pb²⁺ ions in aqueous solution through ion exchange and complexation function. In addition, the established isotherm model and kinetic analyses reveal that the adsorption of Pb²⁺ ions on MONs-SHs follows the secondary reaction kinetic models, where both physisorption and chemisorption contribute to the adsorption of Pb²⁺ ions. The favorable recyclability of MONs-SHs is demonstrated with the maintained adsorption efficiency of 85.35% after six cycles. The results suggest that the synthesized MONs-SHs exhibit considerable application prospects for effectively eliminating Pb²⁺ ions from aqueous solutions. Full article

(This article belongs to the Special Issue Nanostructured Mesoporous and Zeolite-Based Materials: 2nd Edition)

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16 pages, 3787 KiB

Open AccessArticle

Mixed-Matrix Organo–Silica–Hydrotalcite Membrane for CO₂ Separation Part 2: Permeation and Selectivity Study

by Lucas Bünger, Tim Kurtz, Krassimir Garbev, Peter Stemmermann and Dieter Stapf

Membranes 2024, 14(7), 156; https://doi.org/10.3390/membranes14070156 - 12 Jul 2024

Cited by 2 | Viewed by 1751

Abstract

This study introduces an innovative approach to designing membranes capable of separating CO₂ from industrial gas streams at higher temperatures. The novel membrane design seeks to leverage a well-researched, high-temperature CO₂ adsorbent, hydrotalcite, by transforming it into a membrane. This was [...] Read more.

This study introduces an innovative approach to designing membranes capable of separating CO₂ from industrial gas streams at higher temperatures. The novel membrane design seeks to leverage a well-researched, high-temperature CO₂ adsorbent, hydrotalcite, by transforming it into a membrane. This was achieved by combining it with an amorphous organo-silica-based matrix, extending the polymer-based mixed-matrix membrane concept to inorganic compounds. Following the membrane material preparation and investigation of the individual membrane in Part 1 of this study, we examine its permeation and selectivity here. The pure 200 nm thick hydrotalcite membrane exhibits Knudsen behavior due to large intercrystalline pores. In contrast, the organo-silica membrane demonstrates an ideal selectivity of 13.5 and permeance for CO₂ of 1.3 × 10⁻⁷ mol m⁻² s⁻¹ Pa⁻¹ at 25 °C, and at 150 °C, the selectivity is reduced to 4.3. Combining both components results in a hybrid microstructure, featuring selective surface diffusion in the microporous regions and unselective Knudsen diffusion in the mesoporous regions. Further attempts to bridge both components to form a purely microporous microstructure are outlined. Full article

(This article belongs to the Special Issue Advanced Membrane Materials for CO₂ Capture and Separation)

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15 pages, 4596 KiB

Open AccessArticle

Use of Periodic Mesoporous Organosilica–Benzene Adsorbent for CO₂ Capture to Reduce the Greenhouse Effect

by David Cantador-Fernandez, Dolores Esquivel, José Ramón Jiménez and José María Fernández-Rodríguez

Materials 2024, 17(11), 2669; https://doi.org/10.3390/ma17112669 - 1 Jun 2024

Cited by 2 | Viewed by 1030

Abstract

The CO₂ adsorption of a phenylene-bridged ordered mesoporous organosilica (PMO–benzene) was analyzed. The maximum capture capacity was 638.2 mg·g⁻¹ (0 °C and 34 atm). Approximately 0.43 g would be enough to reduce the amount of atmospheric CO₂ in 1 m [...] Read more.

The CO₂ adsorption of a phenylene-bridged ordered mesoporous organosilica (PMO–benzene) was analyzed. The maximum capture capacity was 638.2 mg·g⁻¹ (0 °C and 34 atm). Approximately 0.43 g would be enough to reduce the amount of atmospheric CO₂ in 1 m³ to pre-industrial levels. The CO₂ adsorption data were analyzed using several isotherm models, including Langmuir, Freundlich, Sips, Toth, Dubinin–Radushkevich, and Temkin models. This study confirmed the capability of this material for use in reversible CO₂ capture with a minimal loss of capacity (around 1%) after 10 capture cycles. Various techniques were employed to characterize this material. The findings from this study can help mitigate the greenhouse effect caused by CO₂. Full article

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13 pages, 2569 KiB

Open AccessArticle

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

by Nathan I. Walton, Eric M. Brozek, Courtney C. Gwinn and Ilya Zharov

Colloids Interfaces 2024, 8(2), 18; https://doi.org/10.3390/colloids8020018 - 7 Mar 2024

Cited by 2 | Viewed by 2230

Abstract

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 [...] Read more.

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. Full article

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14 pages, 8632 KiB

Open AccessArticle

GSH-Triggered/Photothermal-Enhanced H₂S Signaling Molecule Release for Gas Therapy

by Xinqiang Liang, Mekhrdod S. Kurboniyon, Yuanhan Zou, Kezong Luo, Shuhong Fang, Pengle Xia, Shufang Ning, Litu Zhang and Chen Wang

Pharmaceutics 2023, 15(10), 2443; https://doi.org/10.3390/pharmaceutics15102443 - 10 Oct 2023

Cited by 7 | Viewed by 1942

Abstract

Traditional treatment methods for tumors are inefficient and have severe side effects. At present, new therapeutic methods such as phototherapy, chemodynamic therapy, and gasodynamic therapy have been innovatively developed. High concentrations of hydrogen sulfide (H₂S) gas exhibit cancer-suppressive effects. Herein, a [...] Read more.

Traditional treatment methods for tumors are inefficient and have severe side effects. At present, new therapeutic methods such as phototherapy, chemodynamic therapy, and gasodynamic therapy have been innovatively developed. High concentrations of hydrogen sulfide (H₂S) gas exhibit cancer-suppressive effects. Herein, a Prussian blue-loaded tetra-sulfide modified dendritic mesoporous organosilica (PB@DMOS) was rationally constructed with glutathione (GSH)-triggered/photothermal-enhanced H₂S signaling molecule release properties for gas therapy. The as-synthesized nanoplatform confined PB nanoparticles in the mesoporous structure of organosilica silica due to electrostatic adsorption. In the case of a GSH overexpressed tumor microenvironment, H₂S gas was controllably released. And the temperature increases due to the photothermal effects of PB nanoparticles, further enhancing H₂S release. At the same time, PB nanoparticles with excellent hydrogen peroxide catalytic performance also amplified the efficiency of tumor therapy. Thus, a collective nanoplatform with gas therapy/photothermal therapy/catalytic therapy functionalities shows potential promise in terms of efficient tumor therapy. Full article

(This article belongs to the Section Biologics and Biosimilars)

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2 pages, 777 KiB

Open AccessCorrection

Correction: Rajabi et al. Efficient Synthesis of Dihydropyrimidines Using a Highly Ordered Mesoporous Functionalized Pyridinium Organosilica. Catalysts 2022, 12, 350

by Fatemeh Rajabi, Mika Sillanpää, Christophe Len and Rafael Luque

Catalysts 2023, 13(8), 1153; https://doi.org/10.3390/catal13081153 - 26 Jul 2023

Viewed by 1152

Abstract

In the original publication [...] Full article

(This article belongs to the Special Issue Exclusive Papers of the Editorial Board Members (EBMs) of Catalysts)

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13 pages, 5061 KiB

Open AccessArticle

Mesoporous Silicas Obtained by Time-Controlled Co-Condensation: A Strategy for Tuning Structure and Sorption Properties

by Mariusz Barczak, Dorota Pietras-Ożga, Moaaz K. Seliem, Giacomo de Falco, Dimitrios A. Giannakoudakis and Konstantinos Triantafyllidis

Nanomaterials 2023, 13(14), 2065; https://doi.org/10.3390/nano13142065 - 13 Jul 2023

Cited by 6 | Viewed by 1944

Abstract

Mesoporous silicas synthesized by the co-condensation of two and three different silica monomers were synthesized by varying the time intervals between the addition of individual monomers, while the total time interval was kept constant. This resulted in different structural properties of the final [...] Read more.

Mesoporous silicas synthesized by the co-condensation of two and three different silica monomers were synthesized by varying the time intervals between the addition of individual monomers, while the total time interval was kept constant. This resulted in different structural properties of the final silicas, particularly in their porosity and local ordering. One of the obtained samples exhibited an unusual isotherm with two hysteresis loops and its total pore volume was as high as 2.2 cm³/g. In addition, to be thoroughly characterized by a wide range of instrumental techniques, the obtained materials were also employed as the adsorbents and release platforms of a diclofenac sodium (DICL; used here as a model drug). In the case of DICL adsorption and release, differences between the samples were also revealed, which confirms the fact that time control of a monomer addition can be successfully used to fine-tune the properties of organo-silica materials. Full article

(This article belongs to the Special Issue Synthesis and Characterization of Porous Hybrid Nanomaterials)

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16 pages, 35205 KiB

Open AccessArticle

Dendritic Mesoporous Organosilica Nanoparticles with Photosensitizers for Cell Imaging, siRNA Delivery and Protein Loading

by Haneen Omar, Sara Jakimoska, Julia Guillot, Edreese Alsharaeh, Clarence Charnay, Frédérique Cunin, Aurélie Bessière, Jean-Olivier Durand, Laurence Raehm, Laure Lichon, Mélanie Onofre and Magali Gary-Bobo

Molecules 2023, 28(14), 5335; https://doi.org/10.3390/molecules28145335 - 11 Jul 2023

Cited by 2 | Viewed by 2437

Abstract

Dendritic mesoporous organosilica nanoparticles (DMON) are a new class of biodegradable nanoparticles suitable for biomolecule delivery. We studied the photochemical internalization (PCI) and photodynamic therapy (PDT) of DMON to investigate new ways for DMON to escape from the endosomes-lysosomes and deliver biomolecules into [...] Read more.

Dendritic mesoporous organosilica nanoparticles (DMON) are a new class of biodegradable nanoparticles suitable for biomolecule delivery. We studied the photochemical internalization (PCI) and photodynamic therapy (PDT) of DMON to investigate new ways for DMON to escape from the endosomes-lysosomes and deliver biomolecules into the cytoplasm of cells. We added photosensitizers in the framework of DMON and found that DMON were loaded with siRNA or FVIII factor protein. We made four formulations with four different photosensitizers. The photosensitizers allowed us to perform imaging of DMON in cancer cells, but the presence of the tetrasulfide bond in the framework of DMON quenched the formation of singlet oxygen. Fortunately, one formulation allowed us to efficiently deliver proapoptotic siRNA in MCF-7 cancer cells leading to 31% of cancer cell death, without irradiation. As for FVIII protein, it was loaded in two formulations with drug-loading capacities (DLC) up to 25%. In conclusion, DMON are versatile nanoparticles capable of loading siRNA and delivering it into cancer cells, and also loading FVIII protein with good DLC. Due to the presence of tetrasulfide, it was not possible to perform PDT or PCI. Full article

(This article belongs to the Collection Porous Materials)

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14 pages, 2685 KiB

Open AccessArticle

Flexible Humidity Sensor Based on Au Nanoparticles/Organosilica-Containing Polyelectrolyte Composite

by Pi-Guey Su and Chih-Chang Hsu

Chemosensors 2023, 11(5), 291; https://doi.org/10.3390/chemosensors11050291 - 13 May 2023

Cited by 2 | Viewed by 2325

Abstract

A novel flexible humidity sensor incorporating gold nanoparticles (Au NPs) and a trifunctional organosilica compound has been developed through the integration of sol–gel processing, free radical polymerization, and self-assembly techniques. The trifunctional organosilica was initially synthesized by modifying (3-mercaptopropyl)trimethoxysilane (thiol-MPTMS) with 3-(trimethoxysilyl)propyl methacrylate [...] Read more.

A novel flexible humidity sensor incorporating gold nanoparticles (Au NPs) and a trifunctional organosilica compound has been developed through the integration of sol–gel processing, free radical polymerization, and self-assembly techniques. The trifunctional organosilica was initially synthesized by modifying (3-mercaptopropyl)trimethoxysilane (thiol-MPTMS) with 3-(trimethoxysilyl)propyl methacrylate (vinyl-TMSPMA). Subsequently, a hydrophilic polyelectrolyte, [3(methacryloylamino)propyl]trimethyl ammonium chloride (MAPTAC), was grafted onto the MPTMS-TMSPMA gel. The Au NPs were assembled onto the thiol groups present in the MPTMS-TMSPMA-MAPTAC gel network. The compositional and microstructural properties of the Au NPs/MPTMS-TMSPMA-MAPTAC composite film were investigated utilizing Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The presence of thiol groups and mesoporous silica skeletons ensured the stability of the humidity-sensing film on the substrate under highly humid conditions, while the hydrophilic groups functioned as humidity-sensitive sites. This innovative humidity sensor demonstrated high sensitivity, acceptable linearity, minimal hysteresis, and rapid response time across a broad range of working humidity levels. Based on the complex impedance spectra analysis, hydronium ions (H₃O⁺) were determined to govern the conductance process of the flexible humidity sensor. Full article

(This article belongs to the Section Materials for Chemical Sensing)

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13 pages, 4188 KiB

Open AccessArticle

Polyoxometalates Encapsulated into Hollow Periodic Mesoporous Organosilica as Nanoreactors for Extraction Oxidation Desulfurization

by Yan Gao, Yu Chen, Cuiying Wang, Aiping Yin, Hailong Li and Jianshe Zhao

Catalysts 2023, 13(4), 747; https://doi.org/10.3390/catal13040747 - 14 Apr 2023

Cited by 5 | Viewed by 1667

Abstract

In this work, the highly active polyoxometalate (PW₂Mo₂) with Venturello structure and its corresponding catalyst were applied in catalytic desulfurization for the first time. PW₂Mo₂ as an active component was effectively encapsulated in hollow periodic mesoporous [...] Read more.

In this work, the highly active polyoxometalate (PW₂Mo₂) with Venturello structure and its corresponding catalyst were applied in catalytic desulfurization for the first time. PW₂Mo₂ as an active component was effectively encapsulated in hollow periodic mesoporous organosilica (HPMOS) to form the nanoreactor PW₂Mo₂@HPMOS, where the central cavity and mesoporous shell facilitate mass transfer and both provide a stable place to react with organic sulfides. Desulfurization test results show that the hollow nanoreactor PW₂Mo₂@HPMOS can almost remove four sulfides simultaneously from diesel in 2 h under mild conditions. Besides, the nanocatalyst PW₂Mo₂@HPMOS can be reused and recycled for at least seven consecutive tests without any noticeable loss in performance. With the rapid development of the economy, the massive use of sulfur-containing fuel has a huge impact on the global climate. After combustion of sulfur-containing fuel, the realized SO_X is an important inducement of the formation of acid rain, and the realized sulfur particle is also a major source of haze. Therefore, removing sulfur compounds from fuel is an important issue that needs to be solved immediately. Full article

(This article belongs to the Special Issue Advances in Graphene/Nanocomposites for Catalytic Applications)

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12 pages, 2920 KiB

Open AccessArticle

Mesoporous Organosilica Nanoparticles to Fight Intracellular Staphylococcal Aureus Infections in Macrophages

by Manasi Jambhrunkar, Sajedeh Maghrebi, Divya Doddakyathanahalli, Anthony Wignall, Clive A. Prestidge and Kristen E. Bremmell

Pharmaceutics 2023, 15(4), 1037; https://doi.org/10.3390/pharmaceutics15041037 - 23 Mar 2023

Cited by 5 | Viewed by 2088

Abstract

Intracellular bacteria are inaccessible and highly tolerant to antibiotics, hence are a major contributor to the global challenge of antibiotic resistance and recalcitrant clinical infections. This, in tandem with stagnant antibacterial discovery, highlights an unmet need for new delivery technologies to treat intracellular [...] Read more.

Intracellular bacteria are inaccessible and highly tolerant to antibiotics, hence are a major contributor to the global challenge of antibiotic resistance and recalcitrant clinical infections. This, in tandem with stagnant antibacterial discovery, highlights an unmet need for new delivery technologies to treat intracellular infections more effectively. Here, we compare the uptake, delivery, and efficacy of rifampicin (Rif)-loaded mesoporous silica nanoparticles (MSN) and organo-modified (ethylene-bridged) MSN (MON) as an antibiotic treatment against small colony variants (SCV) Staphylococcus aureus (SA) in murine macrophages (RAW 264.7). Macrophage uptake of MON was five-fold that of equivalent sized MSN and without significant cytotoxicity on human embryonic kidney cells (HEK 293T) or RAW 264.7 cells. MON also facilitated increased Rif loading with sustained release, and seven-fold increased Rif delivery to infected macrophages. The combined effects of increased uptake and intracellular delivery of Rif by MON reduced the colony forming units of intracellular SCV-SA 28 times and 65 times compared to MSN-Rif and non-encapsulated Rif, respectively (at a dose of 5 µg/mL). Conclusively, the organic framework of MON offers significant advantages and opportunities over MSN for the treatment of intracellular infections. Full article

(This article belongs to the Special Issue Silica-Based Carriers for Drug Delivery)

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11 pages, 2918 KiB

Open AccessCommunication

Mesoporous Organosilica Nanoparticles with Tetrasulphide Bond to Enhance Plasmid DNA Delivery

by Yue Zhang, He Xian, Ekaterina Strounina, Kimberley S. Gunther, Matthew J. Sweet, Chen Chen, Chengzhong Yu and Yue Wang

Pharmaceutics 2023, 15(3), 1013; https://doi.org/10.3390/pharmaceutics15031013 - 22 Mar 2023

Cited by 5 | Viewed by 2624

Abstract

Cellular delivery of plasmid DNA (pDNA) specifically into dendritic cells (DCs) has provoked wide attention in various applications. However, delivery tools that achieve effective pDNA transfection in DCs are rare. Herein, we report that tetrasulphide bridged mesoporous organosilica nanoparticles (MONs) have enhanced pDNA [...] Read more.

Cellular delivery of plasmid DNA (pDNA) specifically into dendritic cells (DCs) has provoked wide attention in various applications. However, delivery tools that achieve effective pDNA transfection in DCs are rare. Herein, we report that tetrasulphide bridged mesoporous organosilica nanoparticles (MONs) have enhanced pDNA transfection performance in DC cell lines compared to conventional mesoporous silica nanoparticles (MSNs). The mechanism of enhanced pDNA delivery efficacy is attributed to the glutathione (GSH) depletion capability of MONs. Reduction of initially high GSH levels in DCs further increases the mammalian target of rapamycin complex 1 (mTORc1) pathway activation, enhancing translation and protein expression. The mechanism was further validated by showing that the increased transfection efficiency was apparent in high GSH cell lines but not in low GSH ones. Our findings may provide a new design principle of nano delivery systems where the pDNA delivery to DCs is important. Full article

(This article belongs to the Special Issue Smart Drug Delivery Strategies Based on Porous Materials)

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29 pages, 4566 KiB

Open AccessEditor’s ChoiceReview

Recent Developments in Sonochemical Synthesis of Nanoporous Materials

by Sylwia Głowniak, Barbara Szczęśniak, Jerzy Choma and Mietek Jaroniec

Molecules 2023, 28(6), 2639; https://doi.org/10.3390/molecules28062639 - 14 Mar 2023

Cited by 73 | Viewed by 9483

Abstract

Ultrasounds are commonly used in medical imaging, solution homogenization, navigation, and ranging, but they are also a great energy source for chemical reactions. Sonochemistry uses ultrasounds and thus realizes one of the basic concepts of green chemistry, i.e., energy savings. Moreover, reduced reaction [...] Read more.

Ultrasounds are commonly used in medical imaging, solution homogenization, navigation, and ranging, but they are also a great energy source for chemical reactions. Sonochemistry uses ultrasounds and thus realizes one of the basic concepts of green chemistry, i.e., energy savings. Moreover, reduced reaction time, mostly using water as a solvent, and better product yields are among the many factors that make ultrasound-induced reactions greener than those performed under conventional conditions. Sonochemistry has been successfully implemented for the preparation of various materials; this review covers sonochemically synthesized nanoporous materials. For instance, sonochemical-assisted methods afforded ordered mesoporous silicas, spherical mesoporous silicas, periodic mesoporous organosilicas, various metal oxides, biomass-derived activated carbons, carbon nanotubes, diverse metal-organic frameworks, and covalent organic frameworks. Among these materials, highly porous samples have also been prepared, such as garlic peel-derived activated carbon with an apparent specific surface area of 3887 m²/g and MOF-177 with an SSA of 4898 m²/g. Additionally, many of them have been examined for practical usage in gas adsorption, water treatment, catalysis, and energy storage-related applications, yielding satisfactory results. Full article

(This article belongs to the Special Issue Advances in Ultrasound Chemistry)

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13 pages, 4285 KiB

Open AccessArticle

Improved Photocatalytic H₂ Evolution by Cobaloxime-Tethered Imidazole-Functionalized Periodic Mesoporous Organosilica

by M. Ángeles Navarro, Miguel A. Martín, José Rafael Ruiz, César Jiménez-Sanchidrián, Francisco J. Romero-Salguero and Dolores Esquivel

Hydrogen 2023, 4(1), 120-132; https://doi.org/10.3390/hydrogen4010008 - 2 Feb 2023

Cited by 2 | Viewed by 3087

Abstract

Molecular cobaloxime-based heterogeneous systems have attracted great interest during the last decades in light-driven hydrogen production. Here, we present a novel cobaloxime-tethered periodic mesoporous organosilica (PMO) hybrid (Im-EtPMO-Co) prepared through the immobilization of a molecular cobaloxime complex on the imidazole groups present in [...] Read more.

Molecular cobaloxime-based heterogeneous systems have attracted great interest during the last decades in light-driven hydrogen production. Here, we present a novel cobaloxime-tethered periodic mesoporous organosilica (PMO) hybrid (Im-EtPMO-Co) prepared through the immobilization of a molecular cobaloxime complex on the imidazole groups present in ethylene-bridged PMO. The successful assembly of a molecular cobaloxime catalyst via cobalt-imidazole axial ligation has been evidenced by several techniques, such as ¹³C NMR, Raman spectroscopy, ICP-MS, and XPS. The catalytic performance of Im-EtPMO-Co catalyst was essayed on the hydrogen evolution reaction (HER) under visible light in presence of a photosensitizer (Eosin Y) and an electron donor (TEOA). It showed an excellent hydrogen production of 95 mmol hydrogen at 2.5 h, which corresponded to a TON of 138. These results reflect an improved photocatalytic activity with respect to its homogenous counterpart [Co(dmgH)₂(Im)Cl] as well as a previous cobaloxime-PMO system with pyridine axial ligation to the cobaloxime complex. Full article

(This article belongs to the Special Issue Catalysts for Hydrogen Generation)

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