Reduced graphene oxide/CoS2 porous nanoparticle hybrid electrode material for supercapacitor application

The unique porosity derived from sulphur templates enables easy diffusion of electrolyte ions and improved electrochemical performance is obtained.

Multicolor properties and applications of Ln3+ doped hierarchical NaY(WO4)2via a facile solvothermal process

A modified method to synthesise NaY(WO₄)₂:Ln³⁺ with hierarchical structure and luminescence properties was investigated in this work.

Enzyme immobilisation on poly-l-lysine-containing calcium phosphate particles for highly sensitive glucose detection

High catalytic activities of enzymes are necessary for enzyme immobilising technology for the development of glucose sensors. The aim of this study is to synthesise two types of poly(l-lysine)-containing calcium phosphate particles (pLys-HAp) and to achieve the immobilisation of glucose oxidase (GOX) on them. The oxidation activity of GOX immobilised on these particles was more than 80% compared to that of native GOX (considered to be 100%). Additionally, the relative activity of GOX immobilised on poly-ε-lysine-containing HAp (ε-pLys-HAp) remained approximately 70% after ten cycles. Moreover, glucose detection was able to be performed in the linear range of 4–400 μM using GOX immobilised on pLys-HAp composites. In the direct electrochemistry measurement using the cyclic voltammetry (CV) method, a glassy carbon electrode (GCE) modified by ε-pLys-HAp was a good enzyme electrode and can be used for glucose detection with high sensitivity. From these results, poly(l-lysine)-containing HAp composites can be expected to be enzyme immobilisation agents with high stability and biosensors with high sensitivity.

The as-synthesised poly-l-lysine-containing HAp with high enzyme stability could be a candidate for a glucose sensor with high sensitivity.

High-level nitrogen-doped, micro/mesoporous carbon as an efficient metal-free electrocatalyst for the oxygen reduction reaction: optimizing the reaction surface area by a solvent-free mechanochemical method

Acting as an efficient metal-free ORR electrocatalyst, nitrogen-doped porous carbon derived from coconut mesocarp was prepared by a solvent-free ball-milling process.

Improved visible-light photoactivities of porous LaFeO3 by coupling with nanosized alkaline earth metal oxides and mechanism insight

It is significant to improve visible-light photoactivities of porous LaFeO₃ by coupling with nanosized alkaline earth metal oxides as dual-functional platform for accepting the high level electrons and activating CO₂.

Trifunctional metal–organic platform for environmental remediation: structural features with peripheral hydroxyl groups facilitate adsorption, degradation and reduction processes

A Cd(ii)-based metal–organic framework (MOF) has been demonstrated to have trifunctional properties, namely as an efficient and selective adsorbent for dyes, a visible-light-active photocatalyst for the degradation of dyes and a photocatalyst for Cr(vi) reduction.

Ultrasmall Metal Nanoparticles Confined within Crystalline Nanoporous Materials: A Fascinating Class of Nanocatalysts

Crystalline nanoporous materials with uniform porous structures, such as zeolites and metal-organic frameworks (MOFs), have proven to be ideal supports to encapsulate ultrasmall metal nanoparticles (MNPs) inside their void nanospaces to generate high-efficiency nanocatalysts. The nanopore-encaged metal catalysts exhibit superior catalytic performance as well as high stability and catalytic shape selectivity endowed by the nanoporous matrix. In addition, the synergistic effect of confined MNPs and nanoporous frameworks with active sites can further promote the catalytic activities of the composite catalysts. Herein, recent progress in nanopore-encaged metal nanocatalysts is reviewed, with a special focus on advances in synthetic strategies for ultrasmall MNPs (<5 nm), clusters, and even single atoms confined within zeolites and MOFs for various heterogeneous catalytic reactions. In addition, some advanced characterization methods to elucidate the atomic-scale structures of the nanocatalysts are presented, and the current limitations of and future opportunities for these fantastic nanocatalysts are also highlighted and discussed. The aim is to provide some guidance for the rational synthesis of nanopore-encaged metal catalysts and to inspire their further applications to meet the emerging demands in catalytic fields.

Construction of polyporous polymer microspheres with a tailored mesoporous wall

Polymer microspheres with a novel hierarchically porous structure (inner macropores and a mesoporous wall) were fabricated by taking advantage of γ-ray-radiation-initiated dispersion polymerization.

Optical radiation stability of ZnO hollow particles

Zinc oxide has multifunctional physical properties depending on its microstructure and morphology. Herein, we reported the in situ investigations of the radiation stability of ZnO particles with hollow, ball, star and flower shapes under electron and proton irradiation. 100 keV protons with a fluence of 5 × 10¹⁵ cm^-2 and 50 keV electrons with fluence ranging from 0.5 to 7 × 10¹⁶ cm^-2 are employed to investigate the radiation stability of nanostructured ZnO particles. In situ reflectance, X-ray photoelectron spectra and photoluminescence were characterized in the irradiation environment to avoid the effects of the atmospheric environment on radiation induced defects. The experimental results reveal that, compared to the other shapes, the hollow structure with the best radiation stability due to the hollow structure facilitates the decrease of the accumulation of radiation defects. This study clearly demonstrates the promise of ZnO hollow particles as a plasmonic nanostructure for achieving high radiation stability, and they could be easily employed to serve as the radiation stability pigment for coatings.

Synthesis, Characterization and Photocatalytic Activity of Nanocrystalline First Transition-Metal (Ti, Mn, Co, Ni and Zn) Oxisde Nanofibers by Electrospinning

In this work, five nanocrystalline first transition-metal (Ti, Mn, Co, Ni and Zn) oxide nanofibers were prepared by electrospinning and controlled calcination. The morphology, crystal structure, pore size distribution and specific surface area were systematically studied by scanning electron microscope (SEM), transmission electron microscope (TEM), surface and pore analysis, and thermo gravimetric analyzer (TGA). The results reveal that the obtained nanofibers have a continuously twisted three-dimensional scaffold structure and are composed of neat nanocrystals with a necklace-like arrangement. All the samples possess high specific surface areas, which follow the order of NiO nanofiber (393.645 m2/g) > TiO2 nanofiber (121.445 m2/g) > ZnO nanofiber (57.219 m2/g) > Co3O4 nanofiber (52.717 m2/g) > Mn2O3 nanofiber (18.600 m2/g). Moreover, the photocatalytic degradation of methylene blue (MB) in aqueous solution was investigated in detail by employing the five kinds of metal oxide nanofibers as photocatalysts under ultraviolet (UV) irradiation separately. The results show that ZnO, TiO2 and NiO nanofibers exhibit excellent photocatalytic efficiency and high cycling ability to MB, which may be ascribed to unique porous structures and the highly efficient separation of photogenerated electron-hole pairs. In brief, this paper aims to provide a feasible approach to achieve five first transition-metal oxide nanofibers with excellent performance, which is important for practical applications.

Recent progress in covalent organic framework thin films: fabrications, applications and perspectives

As a newly emerging class of porous materials, covalent organic frameworks (COFs) have attracted much attention due to their intriguing structural merits (e.g., total organic backbone, tunable porosity and predictable structure). However, the insoluble and unprocessable features of bulk COF powder limit their applications. To overcome these limitations, considerable efforts have been devoted to exploring the fabrication of COF thin films with controllable architectures, which open the door for their novel applications. In this critical review, we aim to provide the recent advances in the fabrication of COF thin films not only supported on substrates but also as free-standing nanosheets via both bottom-up and top-down strategies. The bottom-up strategy involves solvothermal synthesis, interfacial polymerization, room temperature vapor-assisted conversion, and synthesis under continuous flow conditions; whereas, the top-down strategy involves solvent-assisted exfoliation, self-exfoliation, mechanical delamination, and chemical exfoliation. In addition, the applications of COF thin films including energy storage, semiconductor devices, membrane-separation, sensors, and drug delivery are summarized. Finally, to accelerate further research, a personal perspective covering their synthetic strategies, mechanisms and applications is presented.

Tailoring Hollow Nanostructures by Catalytic Strategy for Superior Lithium and Sodium Storage

Nowadays, a novel catalyzed strategy for designing 3D carbon nanosheet frameworks is a wide concern in the field of energy storage. Herein, a 3D hollow structure with nickel and nanographitic domains is presented for fabrication of functionalized hollow microporous carbon embedded with expanded defective nanographitic domains or hollow nickel oxide composites. The hollow microporous carbon coupling nanographitic domains exhibits excellent long-term cycling (4000 cycles for lithium storage, 2000 cycles for sodium storage), which is mainly due to the formation of defects in the nanographite for catalytic strategy. The hollow nickel oxide composites show the capacities of 1093 mA h g^-1 after 400 cycles with the high Coulombic efficiency at a current density of 200 mA g^-1 for lithium storage and superior rate performance at different current densities for sodium storage. Stable and great energy storage features stem from the fact that the hollow structure can provide more active sites for ionic diffusion/storage and a free shuttle space for electrons.

Facile Synthesis of Hypercrosslinked Hollow Microporous Organic Capsules for Electrochemical Sensing of CuII Ions

A very simple and facile methodology is used to prepare dithiocarbamate-functionalized hollow microporous organic capsules (HMOCs-DTC), which exhibit excellent stability, a high surface area, and appropriate microporous architecture. In this strategy, SiO₂ particles are used as templates to construct PS-DVB-MAA microspheres, and then dithiocarbamate groups are grafted onto them. The dithiocarbamate-functionalized hypercrosslinked microporous organic capsules (HMOCs-DTC/GC) are then used as an electrode material for the detection of Cu^II ions. Cyclic voltammetry (CV) and electron impedance spectroscopy (EIS) are exploited to study the electrochemical potential of the designed material. The placement of functional groups (dithiocarbamate) at the mesopore interface effectively enhances the mass transfer, which facilitates the more selective detection of Cu^II ions. The high sensitivity of the modified electrode is expressed in terms of current (I_p ) enhancement at extremely low concentrations of Cu^II ions. Thus, a functional and robust porous material (HMOCs-DTC) presents a sensitive sensing ability, displaying the calibration response over a wide linear range (2.50×10^-11 -3.50×10^-10  m), with a lowest limit of detection of 1.02×10^-11  m. Indeed, these HMOCs present a new class of porous polymers possessing extraordinarily high scalability but avoiding complex and expensive synthetic methodologies, promoting its practical utilization.

Nanostructured Metal Catalysts for Selective Hydrogenation and Oxidation of Cellulosic Biomass to Chemicals

Conversion of biomass to chemicals provides essential products to human society from renewable resources. In this context, achieving atom-economical and energy-efficient conversion with high selectivity towards target products remains a key challenge. Recent developments in nanostructured catalysts address this challenge reporting remarkable performances in shape and morphology dependent catalysis by metals on nano scale in energy and environmental applications. In this review, most recent advances in synthesis of heterogeneous nanomaterials, surface characterization and catalytic performances for hydrogenation and oxidation for biorenewables with plausible mechanism have been discussed. The perspectives obtained from this review paper will provide insights into rational design of active, selective and stable catalytic materials for sustainable production of value-added chemicals from biomass resources.

Gated Materials: Installing Macrocyclic Arenes-Based Supramolecular Nanovalves on Porous Nanomaterials for Controlled Cargo Release

Supramolecular nanovalves are an emerging class of important elements that are functionalized on the surfaces of inorganic or hybrid nanocarriers in the constructions of smart cargo delivery systems. Taking advantage of the pseudorotaxane structure via host-guest complexation and the dynamic nature of supramolecular interactions, macrocyclic arene-based supramolecular nanovalves have shown great promise in the applications of drug delivery and controlled release. Careful selection of diverse external stimuli, such as pH variations, temperature changes, redox, enzymes, light irradiation, and competitive binding, can activate the opening and closing of the nanovalves by altering the supramolecular structure or binding affinities. Meanwhile, the porous solid supports in controlled release systems also play an important role in the functionalities of the nanocarriers, which include, but not limited to, mesoporous silica nanoparticles (MSNs), metal-organic frameworks (MOFs), core-shell nanomaterials, and rare-earth porous nanomaterials. The elaborate decoration by macrocyclic arenes-based supramolecular nanovalves on porous nanomaterials has provided intelligent controlled release platforms. In this review, we will focus on the overview of supramolecular nanovalves based on two typical macrocyclic arenes, that is, calixarenes and pillarenes, and their operation manners in the controlled release processes.

Fast detection and structural identification of carbocations on zeolites by dynamic nuclear polarization enhanced solid-state NMR

Acidic zeolites are porous aluminosilicates used in a wide range of industrial processes such as adsorption and catalysis. The formation of carbocation intermediates plays a key role in reactivity, selectivity and deactivation in heterogeneous catalytic processes. However, the observation and determination of carbocations remain a significant challenge in heterogeneous catalysis due to the lack of selective techniques of sufficient sensitivity to detect their low concentrations. Here, we combine 13C isotopic enrichment and efficient dynamic nuclear polarization magic angle spinning nuclear magnetic resonance spectroscopy to detect carbocations in zeolites. We use two dimensional 13C-13C through-bond correlations to establish their structures and 29Si-13C through-space experiments to quantitatively probe the interaction between multiple surface sites of the zeolites and the confined hydrocarbon pool species. We show that a range of various membered ring carbocations are intermediates in the methanol to hydrocarbons reaction catalysed by different microstructural β-zeolites and highlight that different reaction routes for the formation of both targeted hydrocarbon products and coke exist. These species have strong van der Waals interaction with the zeolite framework demonstrating that their accumulation in the channels of the zeolites leads to deactivation. These results enable understanding of deactivation pathways and open up opportunities for the design of catalysts with improved performances.

Mesoporogen-Free Synthesis of Hierarchical SAPO-34 with Low Template Consumption and Excellent Methanol-to-Olefin Conversion

Significant interest has emerged in the development of nanometer-sized and hierarchical silicoaluminophosphate zeolites (SAPO-34) because of their enhanced accessibility and improved catalytic activity for methanol-to-olefin (MTO) conversion. A series of nanometer-sized SAPO-34 catalysts with tunable hierarchical structures was synthesized in a Al₂ O₃ /H₃ PO₄ /SiO₂ /triethylamine(TEA)/H₂ O system by using a mesoporogen-free nanoseed-assisted method. The nanometer-sized hierarchical S_H -3.0 catalyst (TEA/Al₂ O₃ =3.0) possessed the highest crystallinity, highest abundance of intracrystalline meso-/macropores, and the most suitable acidity among all obtained catalysts, showing the highest ethylene and propylene selectivity of 85.4 %. This is the highest reported selectivity for MTO reactions under similar conditions. Detailed analysis of the coke produced during the reaction revealed that the small-sized methyl-substituted benzene and bulky methyl-substituted pyrene were mainly located inside the crystals instead of on the surface of the crystals, which provided further insight into understanding the deactivation of the SAPO-34 catalyst during MTO reaction. Significantly, the simple and cost-effective synthetic process and superb catalytic performance of the nanometer-sized hierarchical SAPO-34 is promising for their practical large-scale application for MTO conversion.

Solvent-Free Mechanochemical Preparation of Hierarchically Porous Carbon for Supercapacitor and Oxygen Reduction Reaction

Hierarchically porous carbon (HPC) derived from fallen flowers was prepared by a green method of combining solvent-free ball milling with the safe activating agent potassium bicarbonate. By regulating the mass ratio of KHCO₃ to biochar, the as-prepared HPC materials possess high specific surface areas of up to 2147.9 m²  g^-1 and abundant hierarchical pores comprised of micro-, meso-, and macropores. The specific capacitances of the HPC materials are able to reach 302.7 F g^-1 at a current density of 0.5 A g^-1 in 6 m KOH, and the symmetric supercapacitor composed of two identical HPC electrodes shows good stability because 100 % of the specific capacitance is retained after 5000 charge/discharge cycles and 90.5 % of the specific capacitance remains after 12 000 cycles. Nitrogen self-doped HPC materials also show higher electrocatalytic activity and stronger methanol tolerance for the oxygen reduction reaction than that of the commercial Pt/C catalyst. This preparation method can be extended to the green conversion of other varieties of biomass waste into useful carbon materials.

From fundamentals to applications: a toolbox for robust and multifunctional MOF materials

In recent years, metal-organic frameworks (MOFs) have been regarded as one of the most important classes of materials. The combination of various metal clusters and ligands, arranged in a vast array of geometries has led to an ever-expanding MOF family. Each year, new and novel MOF structures are discovered. The structural diversity present in MOFs has significantly expanded the application of these new materials. MOFs show great potential for a variety of applications, including but not limited to: gas storage and separation, catalysis, biomedicine delivery, and chemical sensing. This review intends to offer a short summary of some of the most important topics and recent development in MOFs. The scope of this review shall cover the fundamental aspects concerning the design and synthesis of MOFs and range to the practical applications regarding their stability and derivative structures. Emerging trends of MOF development will also be discussed. These trends shall include multicomponent MOFs, defect development in MOFs, and MOF composites. The ever important structure-property-application relationship for MOFs will also be investigated. Overall, this review provides insight into both existing structures and emerging aspects of MOFs.

Dual-Porosity Hollow Carbon Spheres with Tunable Through-Holes for Multi-Guest Delivery

Dual-porosity hollow carbon spheres (DPHCs) with small mesopores (2-4 nm) and large through-holes (20-30 nm) in shells were successfully synthesized using colloidal silica as the template, small silica nanoparticles as nanomasks, and nontoxic dopamine as the carbon precursor followed by post-carbonization and etching. The synthesized DPHCs were further oxidized to be hydrophilic and then used to simultaneously deliver the protein bovine serum albumin (21 × 4 × 14 nm³) and the small molecule doxorubicin (<1 nm), which exhibited a high loading capacity of 689.4 and 1421.2 mg/g, respectively. The release of these two guest molecules can be controlled independently under the stimuli of heat and acidity. In vitro and in vivo experiments also proved that the DPHCs are promising for the co-delivery of multiple cargoes of different sizes.

Synthesis of Stable Hierarchical MIL-101(Cr) with Enhanced Catalytic Activity in the Oxidation of Indene

Nowadays, the controllable synthesis of stable hierarchical metal–organic frameworks (MOFs) is very important for practical applications, especially in catalysis. Herein, a well-known chromium–benzenedicarboxylate metal–organic framework, MIL-101(Cr), with a stable hierarchical structure, was produced by using phenylphosphonic acid (PPOA) as a modulator via the hydrothermal method. The presence of phenylphosphonic acid could create structural defects and generate larger mesopores. The synthesized hierarchical MIL-101(Cr) possesses relatively good porosity, and the larger mesopores had widths of 4–10 nm. The hierarchical MIL-101(Cr) showed significant improvement for catalytic activity in the oxidation of indene. Further, the presence of a hierarchical structure could largely enhance large dye molecule uptake properties by impregnating.

Mesoporous Metal-Organic Frameworks: Synthetic Strategies and Emerging Applications

Metal-organic frameworks (MOFs) have attracted much attention over the past two decades due to their highly promising applications not only in the fields of gas storage, separation, catalysis, drug delivery, and sensors, but also in relatively new fields such as electric, magnetic, and optical materials resulting from their extremely high surface areas, open channels and large pore cavities compared with traditional porous materials like carbon and inorganic zeolites. Particularly, MOFs involving pores within the mesoscopic scale possess unique textural properties, leading to a series of research in the design and applications of mesoporous MOFs. Unlike previous Reviews, apart from focusing on recent advances in the synthetic routes, unique characteristics and applications of mesoporous MOFs, this Review also mentions the derivatives, composites, and hierarchical MOF-based systems that contain mesoporosity, and technical boundaries and challenges brought by the drawbacks of mesoporosity. Moreover, this Review subsequently reveals promising perspectives of how recently discovered approaches to different morphologies of MOFs (not necessarily entirely mesoporous) and their corresponding performances can be extended to minimize the shortcomings of mesoporosity, thus providing a wider and brighter scope of future research into mesoporous MOFs, but not just limited to the finite progress in the target substances alone.

Ultrasmall Plasmonic Nanoparticles Decorated Hierarchical Mesoporous TiO2 as an Efficient Photocatalyst for Photocatalytic Degradation of Textile Dyes

Hierarchical mesoporous TiO₂ was synthesized via a solvothermal technique. The sonochemical method was adopted to decorate plasmonic nanoparticles (NPs) (Ag, Au) on the pores of mesoporous TiO₂. The crystallinity, structure, and morphology were determined to understand the physicochemical nature of the nanocomposites. The catalytic efficiency of the plasmonic nanocatalysts was tested for the azo dyes (congo red, methyl orange, acid orange 10, and remazol red) under solar and visible light irradiations. The generation of hydroxyl radicals was also studied using terephthalic acid as a probe molecule. An attempt was made to understand the influence of size, work function and Fermi level of the metal NPs toward the efficiency of the photocatalyst. The efficiency of the nanocomposites was found to be in the order of P25 < mesoporous TiO₂ < mesoporous Ag-TiO₂ < mesoporous Au-TiO₂ nanospheres under both direct solar light and visible light irradiation. The results indicated that the adsorption of dye, anatase phase, and surface plasmon resonance of NPs favored the effective degradation of dyes in aqueous solution. Further, the efficiency of the catalyst was also tested for xanthene (rose bengal), rhodamine (rhodamine B, rhodamine 6G), and thiazine (methylene blue) dyes. Both TiO₂ and NPs (Ag & Au) possess a huge potential as an eco-friendly photocatalyst for wastewater treatment.

One-Pot Fabrication of Perforated Graphitic Carbon Nitride Nanosheets Decorated with Copper Oxide by Controlled Ammonia and Sulfur Trioxide Release for Enhanced Catalytic Activity

In this article, we have judiciously interfaced copper oxides with graphitic carbon nitride (g-C₃N₄) from thermal reaction of melamine and copper sulfate in a one-pot protocol and manipulated the perforated sheet morphology thereafter. The CCN-X (X = 30, 40, 50, 60, and 70, depending on the wt % of CuSO₄·5H₂O) nanocomposites were prepared by homogenously mixing different percentages of CuSO₄·5H₂O with melamine from a solid-state thermal reaction in a furnace in air. Drastic lowering of CuSO₄ decomposition temperature due to Cu(II)-amine complex formation and subsequent reduction of Cu(II) species by in situ produced ammonia (NH₃) resulted in the production of CuO and catalytic amount of Cu₂O, homogeneously dispersed within the perforated g-C₃N₄ nanosheet. How perforated sheet morphology evolved by combined effect of NH₃, released from thermal condensation of melamine ensuring two-dimensional (2D) growth, and sulfur trioxide (SO₃), expelled from CuSO₄·5H₂O facilitating the perforation, yielding better catalytic performance, has been elucidated. Excess NH₃ from added NH₄Cl removed perforation and ensued a marked decrease in efficacy. However, a high proportion of CuSO₄·5H₂O ruptured the framework of 2D sheets because of excess SO₃ evolution. Among the different nanocomposites synthesized, CCN-40 (CuO-Cu₂O/g-C₃N₄) showed the highest catalytic activity for 4-nitrophenol reduction. Thus, enhanced efficiency of the copper oxide catalyst by interfacing it with an otherwise inactive g-C₃N₄ platform was achieved.

Distinctive Construction of Chitin-Derived Hierarchically Porous Carbon Microspheres/Polyaniline for High-Rate Supercapacitors

Recently, nanostructured porous carbons are attracting significant interest in various important applications. However, a green and innovative method to fabricate hierarchically porous-structured carbon is still a challenge. In the present work, hierarchically porous carbon microspheres (HCMs) were prepared by pyrolyzing the chitin microspheres fabricated from a chitin/chitosan blend solution, in which chitosan was used as a forming agent of nanopores/nanochannels to construct the microspheres. The HCM displayed hierarchical porous structure and improved specific surface area of 1450 m²/g. For the application of HCM in hybrid electrode materials as supercapacitors, polyaniline (PANI) nanoclusters were further deposited on the surface of HCM. A symmetric supercapacitor based on HCM-PANI exhibited high rate capability with retaining over 64% of the capacitance as the scan rate increased from 2 to 500 mV/s. This work introduced a distinctive and green method to fabricate hierarchically porous carbon materials, having considerable application prospect for energy storage.

Highly crumpled nanocarbons as efficient metal-free electrocatalysts for zinc-air batteries

The rational design of an efficient and robust oxygen reduction reaction (ORR) electrocatalyst is vital for energy conversion and storage systems, especially for metal-air batteries. Herein, we report a highly nanocrumpled and nitrogen, phosphorus-codoped nanocarbon (NC-NPC) synthesized by direct pyrolysis of melamine and triphenylphosphine. With the rich nano-crumpled structure and codoping of heteroatoms, this low-cost catalyst exhibits an excellent ORR performance, and possesses a half-wave potential of 0.84 V vs. RHE, a small Tafel slope of 70.2 mV dec-1, and good electrocatalytic stability. More importantly, it can also be applied in zinc-air batteries as an efficient electrode which delivers an open-circle voltage of 1.38 V, a specific capacity of 782 mA h gZn-1, and a long cycling life of 210 h, superior to the commercial Pt/C catalyst.

Urchin-like hierarchical H-Nb2O5 microspheres: synthesis, formation mechanism and their applications in lithium ion batteries

Urchin-like hierarchical Nb₂O₅ microspheres are successfully synthesized through a facile solvothermal method in glycerol-isopropanol mixed media followed by thermal treatment. The sample is characterized by XRD, FESEM, TEM, HRTEM, BET, and XPS, and the results reveal that the as-formed Nb₂O₅ microspheres have a pseudohexagonal structure and are composed of nanorods with an average diameter of ca. 20 nm. It is found that glycerol not only serves as a solvent but also acts as a reactant; furthermore, isopropanol plays an important part in the morphologies of the products. When used as anodic materials for lithium ion batteries, the Nb₂O₅ microspheres deliver initial discharge capacities of 201.7, 159.7, 148.5, 123.7, and 98.5 mA h g^-1 at the current densities of 0.5, 1, 2, 5, and 10C, respectively. Additionally, the discharge capacity of Nb₂O₅ remains at 105.5 mA h g^-1 even after 500 cycles at a high rate of 5C. The good electrochemical properties of the products may be ascribed to their large surface areas and hierarchical structures.

Combined solid-state NMR, FT-IR and computational studies on layered and porous materials

Understanding the structure-property relationship of solids is of utmost relevance for efficient chemical processes and technological applications in industries. This contribution reviews the concept of coupling three well-known characterization techniques (solid-state NMR, FT-IR and computational methods) for the study of solid state materials which possess 2D and 3D architectures and discusses the way it will benefit the scientific communities. It highlights the most fundamental and applied aspects of the proactive combined approach strategies to gather information at a molecular level. The integrated approach involving multiple spectroscopic and computational methods allows achieving an in-depth understanding of the surface, interfacial and confined space processes that are beneficial for the establishment of structure-property relationships. The role of ssNMR/FT-IR spectroscopic properties of probe molecules in monitoring the strength and distribution of catalytic active sites and their accessibility at the porous/layered surface is discussed. Both experimental and theoretical aspects will be considered by reporting relevant examples. This review also identifies and discusses the progress, challenges and future prospects in the field of synthesis and applications of layered and porous solids.

Suspension Processing of Microporous Metal-Organic Frameworks: A Scalable Route to High-Quality Adsorbents

Metal-Organic Frameworks (MOFs) have been intensively studied for applications such as gas storage, gas separation, catalysis, drug delivery, and more. Typically, the development of MOFs involves a post-synthetic solvent exchange process, which usually requires a significant investment of time, energy, labor, and resources. Herein, we propose a novel post-synthetic processing methodology for commercial and laboratory-scale MOFs called “Suspension Processing.” Suspension processing is a non-destructive, agitation-based technique that provides efficient solvent exchange, pore cleaning, and surface defect removal in MOFs. Suspension processing has shown the capability to significantly improve the surface area and gas uptake properties of microporous MOFs, including PCN-250, UiO-66, and HKUST-1. Suspension processing displays improved time, energy, and labor efficiency, as well as considerably enhanced product quality. These findings confirm suspension processing as a straightforward methodology with applicability as a universal technique for the production of high-quality microporous materials.

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Suspension processing is a viable alternative for traditional solvent exchange methods

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PCN-250, UiO-66, and HKUST-1 all showed increased gas uptake and surface area

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It provides efficient solvent exchange, pore cleaning, and surface defect removal

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The total CH₄ uptake of PCN-250 increased by 11.9%, from 194 to 217 v/v