Showing papers on "Mesoporous material published in 2020"
TL;DR: In this article, the mesoporous hollow carbon spheres were used as the cathode and mesophorous hollow spheres coating Zn foil as the anode for a rechargeable aqueous Zn-ion hybrid supercapacitors.
261 citations
TL;DR: This review paper overviews the progress of BCP-templated mesoporous materials over the past 10 years, with an emphasis on the discussions of synthetic methodologies, the control of materials structures (including morphology and pore size/shape), and potential applications particularly in rechargeable batteries, supercapacitors, electro-/photocatalysis, solar cells, etc.
Abstract: Self-assembly of block copolymers (BCPs) provides a versatile strategy for controllable preparation of a broad range of functional materials with different ordered structures. In recent decades, this soft-templating strategy has been widely utilized for preparing a wide range of mesoporous materials. These porous materials have attracted tremendous interest in energy storage and conversion (ESC) applications in view of their ability to absorb, store, and interact with guest species on their exterior/interior surfaces and in the pore space. Compared with other synthetic approaches, such as template-free and hard-templating methods, BCP soft-templating protocols show great advantages in the construction of large mesopores with diameters between 10-60 nm, which are suitable for applications requiring the storage or hosting of large-sized species/molecules. In addition, this strategy shows incomparable merits in the flexible control of pore size/architecture/wall thickness, which determines the final performance of mesoporous materials in ESC devices. In the last decade, rapid development has been witnessed in the area of BCP-templated mesoporous materials. In this review paper, we overview the progress of this field over the past 10 years, with an emphasis on the discussions of synthetic methodologies, the control of materials structures (including morphology and pore size/shape), and potential applications particularly in rechargeable batteries, supercapacitors, electro-/photocatalysis, solar cells, etc.
231 citations
TL;DR: In this article, a new application of heteroatom doped ordered mesoporous carbon as metal-free catalyst was proposed, and a new approach for the removal of organic contaminants was presented.
215 citations
TL;DR: In this article, a macrocyclic ligand of acetyl dibenzo-20-crown-6-ethers (AcDB20C6) was synthesized and directly embedded onto mesoporous inorganic silica.
Abstract: Crown ether based conjugate material was enabling the high functionality for stable complexation mechanism with cesium (Cs) and attracted the scientific community for potential real radioactive contaminated water treatment. This study was focused on ligand anchored conjugate material for radioactive Cs disposal based on adsorption techniques from nuclear liquid waste in Fukushima with high selectivity. A macrocyclic ligand of acetyl dibenzo-20-crown-6-ethers (AcDB20C6) was synthesized and directly embedded onto mesoporous inorganic silica. The Cs adsorption behavior was carried out with batch equilibrium techniques. The affecting experimental parameters such as solution pH, contact time, initial Cs concentration and competitive adsorption of Na and K ion concentrations were measured and optimized systematically. The sensitive pH range for high Cs removal was with broad range of 5.5–9.0, and the maximum adsorption capacity was 65.06 mg/g by the material at pH 7.0. The results clarified that conjugate material was high selectivity towards Cs even in the presence of a high level of Na and K ions rather than inorganic adsorbent because of the possible Cs-π interaction of the benzene ring from the crown ether ligand. The material was successfully investigated for radioactive Cs disposal for the potential treatment in Fukushima in the connection of in nuclear contaminated water treatment. The adsorbed Cs was desorbed with the eluent of 0.20 M HCl and then simultaneously regenerated at the same into the initial form for the next disposal operation after washing with water. The conjugate material was kept high functionality even in several cycles during adsorption–elution–regeneration processes. Then the proposed material could be used as promising material for selective radioactive Cs disposal from contaminated water in Fukushima, Japan.
198 citations
TL;DR: It is found that the silanol nests enable the rare-earth elements to exist as single atomic species with a substantially higher chemical potential compared with that of the bulk oxide, making it possible for them to diffuse onto Pt through the H2 reduction route.
Abstract: Platinum is a much used catalyst that, in petrochemical processes, is often alloyed with other metals to improve catalytic activity, selectivity and longevity1-5. Such catalysts are usually prepared in the form of metallic nanoparticles supported on porous solids, and their production involves reducing metal precursor compounds under a H2 flow at high temperatures6. The method works well when using easily reducible late transition metals, but Pt alloy formation with rare-earth elements through the H2 reduction route is almost impossible owing to the low chemical potential of rare-earth element oxides6. Here we use as support a mesoporous zeolite that has pore walls with surface framework defects (called 'silanol nests') and show that the zeolite enables alloy formation between Pt and rare-earth elements. We find that the silanol nests enable the rare-earth elements to exist as single atomic species with a substantially higher chemical potential compared with that of the bulk oxide, making it possible for them to diffuse onto Pt. High-resolution transmission electron microscopy and hydrogen chemisorption measurements indicate that the resultant bimetallic nanoparticles supported on the mesoporous zeolite are intermetallic compounds, which we find to be stable, highly active and selective catalysts for the propane dehydrogenation reaction. When used with late transition metals, the same preparation strategy produces Pt alloy catalysts that incorporate an unusually large amount of the second metal and, in the case of the PtCo alloy, show high catalytic activity and selectivity in the preferential oxidation of carbon monoxide in H2.
175 citations
TL;DR: This unique combination of a selective molecular catalyst with a simple and robust semi-conductive material opens new pathways for CO2 catalytic light-driven reduction.
Abstract: Achieving visible-light-driven carbon dioxide reduction with high selectivity control and durability while using only earth abundant elements requires new strategies. Hybrid catalytic material was prepared upon covalent grafting a Co-quaterpyridine molecular complex to semiconductive mesoporous graphitic carbon nitride (mpg-C3N4) through an amide linkage. The molecular material was characterized by various spectroscopic techniques, including XPS, IR, and impedance spectroscopy. It proved to be a selective catalyst for CO production in acetonitrile using a solar simulator with a high 98% selectivity, while being remarkably robust since no degradation was observed after 4 days of irradiation (ca. 500 catalytic cycles). This unique combination of a selective molecular catalyst with a simple and robust semiconductive material opens new pathways for CO2 catalytic light-driven reduction.
168 citations
TL;DR: Control experiments and theoretical calculations demonstrate that the superior ORR catalytic performance of Cu1-SA/NC(meso)-7 catalyst is attributed to the atomically dispersed Cu1+ sites in catalyzing the reaction and the advantage of the introduced mesoporous structure in enhancing the mass transport.
Abstract: Herein, we report efficient single copper atom catalysts that consist of dense atomic Cu sites dispersed on a three-dimensional carbon matrix with highly enhanced mesoporous structures and improved...
160 citations
TL;DR: The elaborate design and synthesis of hybrid hollow nanostructures composed of highly dispersed Co 3 O 4 hollow nanoparticles embedded in the mesoporous walls of carbon nanoboxes as an anode material for lithium-ion batteries exhibit excellent lithium storage performance in terms of high specific capacity, excellent rate capability and cycling stability.
Abstract: Confining nanostructured electrode materials in porous carbon represents an effective strategy for improving the electrochemical performance of lithium-ion batteries. Herein, we report the design and synthesis of hybrid hollow nanostructures composed of highly dispersed Co3 O4 hollow nanoparticles (sub-20 nm) embedded in the mesoporous walls of carbon nanoboxes (denoted as H-Co3 O4 @MCNBs) as an anode material for lithium-ion batteries. The facile metal-organic framework (MOF)-engaged strategy for the synthesis of H-Co3 O4 @MCNBs involves chemical etching-coordination and subsequent two-step annealing treatments. Owing to the unique structural merits including more active interfacial sites, effectively alleviated volume variation, good and stable electrical contact, and easy access of Li+ ions, the H-Co3 O4 @MCNBs exhibit excellent lithium-storage performance in terms of high specific capacity, excellent rate capability, and cycling stability.
159 citations
TL;DR: In this article, the mesoporous carbon nanoframes with hierarchical pore size distribution and atomically dispersed Fe-Nx active sites were synthesized from Fe-doped MOF precursors.
Abstract: Metal–organic frameworks (MOFs) can be utilized as superior precursors to pyrolytically achieve the single-atom catalysts. However, most of the atomic active sites are buried inside the microporous carbon matrix, which severely impedes the accessibility of active sites and limits mass transport. Herein, the mesoporous carbon nanoframes with hierarchical pore size distribution and atomically dispersed Fe–Nx active sites were synthesized from Fe-doped MOF precursors. The dense Fe atoms within the nanostructures are dispersed in single-atom level with metalloporphyrin-like Fe–N4 configuration. The introduction of plentiful large mesopores into the nanoframes would not only enhance the accessibility of abundant single-atom active sites, but also boost mass and charge transports. Such distinctive nanostructure led to exceptional bifunctional electrocatalytic performances for oxygen reduction reaction, with more positive onset potential (1.01 V vs. 0.97 V) and half-wave potential (0.89 V vs. 0.82 V) compared with the commercial Pt/C, and electrochemical carbon dioxide reduction.
145 citations
TL;DR: Various strategies to functionalize SBA-15 mesoporous silica have been reviewed with a view to evaluating its efficacy in different catalytic transformation reactions.
Abstract: The development of advanced materials for heterogeneous catalytic applications requires fine control over the synthesis and structural parameters of the active site. Mesoporous silica materials have attracted increasing attention to be considered as an important class of nanostructured support materials in heterogeneous catalysis. Their large surface area, well-defined porous architecture and ability to incorporate metal atoms within the mesopores lead them to be a promising support material for designing a variety of different catalysts. In particular, SBA-15 mesoporous silica has its broad applicability in catalysis because of its comparatively thicker walls leading to higher thermal and mechanical stability. In this review article, various strategies to functionalize SBA-15 mesoporous silica have been reviewed with a view to evaluating its efficacy in different catalytic transformation reactions. Special attention has been given to the molecular engineering of the silica surface, within the framework and within the hexagonal mesoporous channels for anchoring metal oxides, single-site species and metal nanoparticles (NPs) serving as catalytically active sites.
142 citations
TL;DR: Hierarchically ordered mesoporous materials have gained significant scientific attention due to their high surface areas, uniform porosity over various lengths scales, high volume storage capability, shape selectivity, enhanced mass transport and diffusion.
Abstract: Hierarchically ordered mesoporous materials have gained significant scientific attention due to their high surface areas, uniform porosity over various lengths scales, high-volume storage capability, shape selectivity, enhanced mass transport and diffusion. These materials have been widely applied in the fields of photocatalysis, separation, adsorption, photovoltaic solar cells, energy storage and conversion, chemical sensing, and drug delivery. In general, hierarchically porous materials can be generated in two ways: through sol-gel template approaches and a combination of surfactant-assisted procedures. In this review, we discuss recent progress in the preparation, properties, and potential applications of four hierarchically ordered porous materials: hierarchical mesoporous silica, mesoporous phenolic/carbon, nitrogen-doped mesoporous carbon, and mesoporous/microporous covalent organic frameworks.
TL;DR: A semi- artificial system - containing an immobilized enzyme, formate dehydrogenase, in a light harvesting scaffold - is reported for the conversion of CO2 to formic acid using white light, demonstrating of a feasible pathway for solar-driven carbon fixation.
Abstract: Protection of enzymes with synthetic materials is a viable strategy to stabilize, and hence to retain, the reactivity of these highly active biomolecules in non-native environments. Active syntheti...
TL;DR: The selective catalytic reduction (SCR) technique that converts NOx from the outlet of industrial boilers at low temperature (<200 °C) requires catalysts that possess both the oxidization property and the catalytic property as mentioned in this paper.
Abstract: The selective catalytic reduction (SCR) technique that converts NOx from the outlet of industrial boilers at low temperature (<200 °C) requires catalysts that possess both the oxidization property ...
TL;DR: In this article, mesoporous metal sulfide hybrid (meso-MoS2/CoMo2S4) materials via a soft-templating approach using diblock copolymer polystyrene-block poly(acrylic acid) micelles are reported.
Abstract: Mesoporous metal sulfide hybrid (meso-MoS2/CoMo2S4) materials via a soft-templating approach using diblock copolymer polystyrene-block-poly(acrylic acid) micelles are reported. The formation of the meso-MoS2/CoMo2S4 heterostructures is based on the sophisticated coassembly of dithiooxamide and metal precursors (i.e., Co2+, PMo12), which are subsequently annealed in nitrogen atmosphere to generate the mesoporous material. Decomposing the polymer leaves behind mesopores throughout the spherical MoS2/CoMo2S4 hybrid particles, generating numerous electrochemical active sites in a network of pores that enable faster charge transfer and mass/gas diffusion that enhance the electrocatalytic performance of MoS2/CoMo2S4. Doping the spherical meso-MoS2/CoMo2S4 heterostructures with iron improves the electronic properties of the hybrid meso-Fe-MoS2/CoMo2S4 material and consequently results in its superior electrochemical activities for both hydrogen evolution reaction and oxygen evolution reaction.
TL;DR: It is demonstrated that alloying is an effective strategy to alleviate palladium operation stability due to CO poisoning on surface by co-reduction of palladium and silver precursors in aqueous solution using dioctadecyldimethylammonium chloride as the structure-directing agent.
Abstract: Palladium is a promising material for electrochemical CO2 reduction to formate with high Faradaic efficiency near the equilibrium potential. It unfortunately suffers from problematic operation stability due to CO poisoning on surface. Here, it is demonstrated that alloying is an effective strategy to alleviate this problem. Mesoporous PdAg nanospheres with uniform size and composition are prepared from the co-reduction of palladium and silver precursors in aqueous solution using dioctadecyldimethylammonium chloride as the structure-directing agent. The best candidate can initiate CO2 reduction at zero overpotential and achieve high formate selectivity close to 100% and great stability even at <-0.2 V versus reversible hydrogen electrode. The high selectivity and stability are believed to result from the electronic coupling between Pd and Ag, which lowers the d-band center of Pd and thereby significantly enhances its CO tolerance, as evidenced by both electrochemical analysis and theoretical simulations.
TL;DR: In this article, a mesoporous Ag-doped Co3O4 nanosheets (NSs) was synthesized directly on Ni-foam (NF) via a facile hydrothermal and post-annealing approach.
TL;DR: The architectures of hierarchically mesoporous TiO2 materials, including nanofibers, nanosheets, microparticles, films, spheres, core-shell and multi-level structures are summarized and the challenges and future directions of research and development are outlined.
Abstract: Because of their low cost, natural abundance, environmental benignity, plentiful polymorphs, good chemical stability and excellent optical properties, TiO2 materials are of great importance in the areas of physics, chemistry and material science. Much effort has been devoted to the synthesis of TiO2 nanomaterials for various applications. Among them, mesoporous TiO2 materials, especially with hierarchically porous structures, show great potential owing to their extraordinarily high surface areas, large pore volumes, tunable pore structures and morphologies, and nanoscale effects. This review aims to provide an overview of the synthesis and applications of hierarchically mesoporous TiO2 materials. In the first section, the general synthetic strategies for hierarchically mesoporous TiO2 materials are reviewed. After that, we summarize the architectures of hierarchically mesoporous TiO2 materials, including nanofibers, nanosheets, microparticles, films, spheres, core-shell and multi-level structures. At the same time, the corresponding mechanisms and the key factors for the controllable synthesis are highlighted. Following this, the applications of hierarchically mesoporous TiO2 materials in terms of energy storage and environmental protection, including photocatalytic degradation of pollutants, photocatalytic fuel generation, photoelectrochemical water splitting, catalyst support, lithium-ion batteries and sodium-ion batteries, are discussed. Finally, we outline the challenges and future directions of research and development in this area.
TL;DR: In this paper, mesoporous materials have shown great potential to achieve high-performance electrodes with high energy/power density, long lifetime, increased interfacial reaction activity, and enhanced kinetics.
Abstract: Developing high-performance electrode materials is an urgent requirement for next-generation energy conversion and storage systems. Due to the exceptional features, mesoporous materials have shown great potential to achieve high-performance electrodes with high energy/power density, long lifetime, increased interfacial reaction activity, and enhanced kinetics. In this Essay, applications of mesoporous materials are reviewed in electrochemical energy conversion and storage devices. The synthesis, structure, and properties of mesoporous materials and their performance in rechargeable batteries, supercapacitors, fuel cells, and electrolyzers are discussed, providing practical details and enlightening comments on the construction of high-performance mesoporous electrodes. Lastly, the research challenges and perspectives on mesoporous materials for the future development of energy conversion and storage devices are assessed.
TL;DR: In this paper, the mesoporous MnO@MnOx microspheres were used for the degradation of antibiotic levofloxacin (LEV) using peroxymonosulfate (PMS) as an oxidant under simulated sunlight irradiation.
TL;DR: By adjusting the amount of thiourea, a sulfur-doped hollow carbon microspheres provided with mesoporous shell with different doping ratios by one-step hydrothermal method was successfully prepared.
TL;DR: In this paper, an improved dissolution-capture method is applied for preparation of N-HMCS using 3-aminophenol-formaldehyde (AF) resin spheres as carbon precursor.
TL;DR: In this article, the MCM-41-based mesoporous material synthesizes and its strategic use as an adsorbent material for the removal of different pollutants is discussed.
TL;DR: In this paper, a dual template technique is employed to prepare nitrogen doped polymer-silica nanocomposites with interpenetration twins nano-architectures at the initial stage.
TL;DR: In insights into the potential utilization of COF materials for EDLCs, a series of capacitor cells composed of exfoliated mesoporous 2D covalent organic frameworks that are able to perform excellent double-layer charge storage is reported.
Abstract: The electrochemical double-layer capacitors (EDLCs) are highly demanded electrical energy storage devices due to their high power density with thousands of cycle life compared with pseudocapacitors and batteries. Herein, a series of capacitor cells composed of exfoliated mesoporous 2D covalent organic frameworks (e-COFs) that are able to perform excellent double-layer charge storage is reported. The selected mesoporous 2D COFs possess eclipsed AA layer-stacking mode with 3.4 nm square-like open channels, favorable BET surface areas (up to 1170 m2 g-1 ), and high thermal and chemical stabilities. The COFs via the facile, scalable, and mild chemical exfoliation method are further exfoliated to produce thin-layer structure with average thickness of about 22 nm. The e-COF-based capacitor cells achieve high areal capacitance (5.46 mF cm-2 at 1,000 mV s-1 ), high gravimetric power (55 kW kg-1 ), and relatively low τ0 value (121 ms). More importantly, they perform nearly an ideal DL charge storage at high charge-discharge rate (up to 30 000 mV s-1 ) and maintain almost 100% capacitance stability even after 10 000 cycles. This study thus provides insights into the potential utilization of COF materials for EDLCs.
01 Dec 2020
TL;DR: In this article, the effect of key adsorption parameters such as the bamboo chip activated carbon dose (A: 0.02-0.1 grams/L), pH (B: 3-10), temperature (C: 30-50°C), and time (D: 5-20min) was optimized using a response surface methodology.
Abstract: Bamboo chip (BC) biomass was used as an alternative precursor for producing high surface area and mesoporous bamboo chip activated carbon using KOH activation with pyrolysis process. Various characterization methods were employed to study the morphological characteristics, material crystallinity, surface area property, elemental composition, and surface functional group of the bamboo chip activated carbon (BCAC). The Brunauer–Emmett–Teller analysis showed that the bamboo chip activated carbon has a high surface area (720.69 m2/g) and mesoporous structure (mean pore diameter 7.32 nm). The adsorption property of bamboo chip activated carbon for the removal of methylene blue (MB) from aqueous media was evaluated. The effect of key adsorption parameters such as the bamboo chip activated carbon dose (A: 0.02–0.1 g/L), pH (B: 3–10), temperature (C: 30–50 °C), and time (D: 5–20 min) was optimized using a response surface methodology–Box–Behnken design. The kinetics of adsorption obeyed a pseudo-first order. The adsorption equilibrium was well described by the Freundlich isotherm model. The maximum adsorption capacity (qm) of MB dye was found to be 305.3 mg/g at 40 °C. The MB dye adsorption mechanism onto bamboo chip activated carbon surface indicates various dye–adsorbent interactions: electrostatic attraction, π–π interaction, and H-bonding. This study demonstrates the utility of bamboo chip as a biomass precursor for the efficient synthesis of activated carbon with favorable cationic dye adsorption properties.
TL;DR: In this article, nonoxides have been widely employed as highly efficient catalysts for water splitting, but they suffer from obvious surface transformation and poor structural stability, which must be addressed.
Abstract: Nonoxides have been widely employed as highly efficient catalysts for water splitting. However, these nonoxides suffer from obvious surface transformation and poor structural stability, which must ...
TL;DR: In this article, the photocatalytic efficiency of g-C3N4 was tuned by introducing proportionally-adjustable mesoporous samples, which exhibited higher surface area and larger pore volume.
TL;DR: Exfoliated Ti3C2 MXenes serve as a substrate to perpendicularly grow uniform mesoporous NiCoP nanosheets through an in-situ interface-growth strategy and subsequent phosphorization, which exhibits supe-rior overall water-splitting performance to its building-block counterparts, matching to the state-of-the-art water- Splitting electrocatalysts.
Abstract: The utilization of nonprecious metal electrocatalysts for water-splitting may be the ultimate solution for sustainable and clean hydrogen energy. MXene, an emerging two-dimensional material, exhibits many unique properties such as possible metal-like conductivity, hydrophilic surface, and rich chemistry, rendering a group of promising catalysts and catalyst support materials. In this study, exfoliated Ti3C2 MXenes serve as a substrate to perpendicularly grow uniform mesoporous NiCoP nanosheets through an in situ interface-growth strategy and subsequent phosphorization. The obtained Ti3C2@mNiCoP materials with a stable hierarchical sandwich structure possess excellent conductivity, large surface area, and uniform mesopores with high pore volume. With these beneficial properties, the Ti3C2@mNiCoP material exhibits superior overall water-splitting performance compared with that of its building-block counterparts, matching the state-of-the-art water-splitting electrocatalysts.
TL;DR: In this paper, an ordered mesoporous carbon (SBA-C) with parallel channels, synthesized using SBA-15 as a hard template, is decorated with nanoflowers assembled by porous nickel cobalt sulfide (NiCoS) nanosheets with Al leaching through an oil bath following by a hydrothermal method.
TL;DR: Mesoporous materials with high specific surface, pores volume and unique pore size were recently intensively studied as bio-materials, such as carriers for controlled bio-active principles delivery as discussed by the authors.
Abstract: Mesoporous materials with high specific surface, pores volume and unique pore size were recently intensively studied as bio-materials, such as carriers for controlled bio-active principles delivery. Mesoporous silica materials exhibit greater capacity for drugs loading and insure a controlled bio-active compound release if they are functionalized, in comparison with amorphous colloidal silica. Mesoporous silica nanomaterials have lately earned increasing interest also due to their substantial capability to be used in tumours treatment and imaging. Recently, functionalized mesoporous silica materials known a rapid development in imagistic and curative applications. This review summarizes the recent advancement in the obtaining and biological properties of mesoporous silica nanomaterials, emphasising the synthesis methods and drug delivery application. Commonly used synthetic strategies are discussed, followed by a systematic review of applicability in optical and MRI imaging.