Metal-Organic Frameworks Marry Sponge: New Opportunities for Advanced Water Treatment

Metal-organic frameworks (MOFs) have garnered attention across various fields due to their noteworthy features like high specific surface area, substantial porosity, and adjustable performance. In the realm of water treatment, MOFs exhibit great potential for eliminating pollutants such as organics, heavy metals, and oils. Nonetheless, the inherent powder characteristics of MOFs pose challenges in terms of recycling, pipeline blockage, and even secondary pollution in practical applications. Addressing these issues, the incorporation of MOFs into sponges proves to be an effective solution. Strategies like one-pot synthesis, in situ growth, and impregnation are commonly employed for loading MOFs onto sponges. This review comprehensively explores the synthesis strategies of MOFs and sponges, along with their applications in water treatment, aiming to contribute to the ongoing advancement of MOF materials.

Robust and highly reactive membranes for continuous disposal of chemical warfare agents: Effects of nanostructure and functionality in MOF and nanochitin aerogel composites

Developing appropriate disposal of stockpiles of chemical warfare agents (CWAs) has gained significant attention as their lethal toxicity seriously harms humanity. In this study, a novel green-fabrication method with UiO-66 catalysts and amine-functionalized chitin nanofibers (ChNFs) was suggested to prepare durable and highly reactive membranes for decomposing chemical warfare agents (CWAs) in the continuous flow system. The strong interaction between ChNFs and the UiO-66 led to stable loading of the UiO-66 on the continuous nano-porous channel of the ChNF reactive membrane even with high loading of UiO-66 (70 wt% of UiO-66 in the ChNF substrate). In addition, the Brønsted base functionalities (-NH2 and -NHCOCH3) of the ChNF enhanced the catalytic activity and recyclability of the UiO-66. The resulting 70-ChNF composites can effectively decompose a nerve agent simulant (methyl paraoxon) even after 7 repeatable cycles, which has been not obtained in the previous UiO-66 catalyst. The ChNF/UiO-66 reactive membranes with 1 m2 of the area decomposed 130 g of CWAs within an hour in a continuous flow system. We believe these robust and highly reactive membranes can provide a sustainable and efficient solution for the massive CWA disposal and also contribute to the advancement of functional membrane material science.

High entropy alloying strategy for accomplishing quintuple-nanoparticles grafted carbon towards exceptional high-performance overall seawater splitting

High entropy alloys (HEAs), a novel class of material, have been explored in terms of their excellent mechanical properties. Seawater electrolysis is a step towards sustainable production of carbon-neutral fuels such as H2, O2, and industrially demanding Cl2. Herein, we report a practically viable FeCoNiMnCr HEA nanoparticles system grafted on a conductive carbon matrix for promising seawater electrolysis. The comprehensive kinetics analysis of the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and chlorine evolution reaction (CER) confirms the effectiveness of our system. As an electrocatalyst, HEAs grafted on carbon black show trifunctionality with promising kinetics, selectivity and enduring performance, towards seawater splitting. We optimize high entropy alloy decorated/grafted carbon black (HEACB) catalysts, studying their synthesis temperature to scrutinize the effect of alloy formation variation on the catalysis efficacy. During the catalysis, selectivity between two mutually competing reactions, CER and OER, in the electrochemical catalysis of seawater is controlled by the reaction media pH. We employ Mott-Schottky measurements to probe the band structure of the intrinsically induced metal-semiconductor junction in the HEACB catalyst, where the carrier density and flat band potential are optimized. The HEACB sample provides promising results towards overall seawater electrolysis with a net half-cell potential of about 1.65 V with good stability, which strongly implies its broad practical applicability.

Surface Filtration in Mesoporous Au Films Decorated by Ag Nanoparticles for Solving SERS Sensing Small Molecules in Living Cells

For surface-enhanced Raman spectroscopy (SERS) sensing of small molecules in the presence of living cells, biofouling and blocking of plasmonic centers are key challenges. Here, we have developed a mesoporous Au (AuM) film coated with a Ag nanoparticles (NPs) as a plasmonic sensor (AuM@Ag) to analyze aromatic thiols, which is an example of a small molecule, in the presence of a living cell strain (e.g., MDA-MB-231) as a model living system. The resulting AuM@Ag provides 0.1 nM sensitivity and high reproducibility for thiols sensing. Simultaneously, the AuM@Ag film filters large biomolecules, preventing Raman signals from overlapping produced by large biomolecules. After analysis, the AuM@Ag film undergoes recycling by the full dissolution of the Ag-thiol layer and removal of thiols from AuM. Furthermore, fresh AgNPs are formed for further SERS analysis, which circumvents the Ag oxidation issue. The ease of the AgNPs deposition allows up to 12 cycles of on-demand recycling and sensing even after utilization as a sensor in multicomponent media without enhancement and sensitivity loss. The reported mesoporous film with surface filtering ability and prominent recycling procedure promises to offer a new strategy for the detection of various small molecules in the presence of living cells.

P18.04.A Cay10603, HDAC6 inhibitor, enhances radiosensitivity in meningioma via supressing the nuclear beta-catenin accumulation

Background

Meningioma is the most frequent primary central nervous system tumour (PCNST) which account ca 36% of all PCNST. Due to the lack of efficient chemotherapy for meningioma, radiotherapy often become a first-line treatment especially when the tumour is not operable. Radiotherapy plays a crucial role in local control but its efficacy is restricted by radioresistance and by normal tissue radiation tolerance. Therefore, developing and evaluating potential radiosensitisers to enhance therapeutic efficacy are needed.Histone deacetylase (HDACs) expression is generally increased in many cancer types and regulate the expression of numerous proteins involved in tumorigenesis. Targeting HDAC using HDAC inhibitor (HDACi) represent promising radiosensitisers that affect various biological processes, such as cell survival, apoptosis, and DNA repair.

Material and Methods

We investigated whether pre-treatment with the hydroxamate-based HDAC6 inhibitor, Cay10603, impacts radiation-induced DNA double-strand break (DSB) induction, cell survival, cell cycle arrest, and cell death using immunocytochemistry, clonogenic assay, and flow cytometry in meningioma cell lines. Low concentration (100 nM) of Cay10603 was treated 24 hr prior to high energy x-ray irradiation (2 Gy) by a medical linear accelerator (LINAC). To investigate the nuclear localisation of beta-catenin, subcellular fractionation and Western Blotting were conducted.

Results

We found that tumour cells survival was synergistically decreased after combination treatment of Cay10603 and radiation. Combination therapy induced DNA damage with activation of histone gH2AX and increased G2/M arrest compared to drug or radiation alone. Both apoptotic and necrotic cell death were increased after combination therapy. To focus on the mechanisms of action of HDAC6 inhibition followed by radiation, we further investigated nuclear localisation of beta-catenin levels. The results showed the both beta-catenin and c-myc expression in the nucleus was suppressed after combination therapy.

Conclusion

In meningioma cells, radiotherapy in combination with HDAC6 inhibitor reduces the nuclear localisation of beta-catenin and synergistically decreases cell survival. Our findings demonstrate a potential therapeutic strategy of Cay10603 to improve the radiosensitisation for meningioma cells.

Expeditious Electrochemical Synthesis of Mesoporous Chalcogenide Flakes: Mesoporous Cu2 Se as a Potential High-Rate Anode for Sodium-Ion Battery

Nanostructured copper selenide (Cu₂ Se) attracts much interest as it shows outstanding performance as thermoelectric, photo-thermal, and optical material. The mesoporous structure is also a promising morphology to obtain better performance for electrochemical and catalytic applications, thanks to its high surface area. A simple one-step electrochemical method is proposed for mesoporous chalcogenides synthesis. The synthesized Cu₂ Se material has two types of mesopores (9 and 18 nm in diameter), which are uniformly distributed inside the flakes. These materials are also implemented for sodium (Na) ion battery (NIB) anode as a proof of concept. The electrode employing the mesoporous Cu₂ Se exhibits superior and more stable specific capacity as a NIB anode compared to the non-porous samples. The electrode also exhibits excellent rate tolerance at each current density, from 100 to 1000 mA g^-1 . It is suggested that the mesoporous structure is advantageous for the insertion of Na ions inside the flakes. Electrochemical analysis indicates that the mesoporous electrode possesses more prominent diffusion-controlled kinetics during the sodiation-desodiation process, which contributes to the improvement of Na-ion storage performance.

Electrochemical preparation of nano/micron structure transition metal-based catalysts for the oxygen evolution reaction

Electrochemical water splitting is a promising technology for hydrogen production and sustainable energy conversion, but the existing electrolytic cells lack a sufficient number of robust and highly active anodic electrodes for the oxygen evolution reaction (OER). Electrochemical synthesis technology provides a feasible route for the preparation of independent OER electrodes with high utilization of active sites, fast mass transfer, and a simple preparation process. A comprehensive review of the electrochemical synthesis of nano/microstructure transition metal-based OER materials is provided. First, some fundamentals of electrochemical synthesis are introduced, including electrochemical synthesis strategies, electrochemical synthesis substrates, the electrolyte used in electrochemical synthesis, and the combination of electrochemical synthesis and other synthesis methods. Second, the morphology and properties of electrochemical synthetic materials are summarized and introduced from the viewpoint of structural design. Then, the latest progress regarding the development of transition metal-based OER electrocatalysts is reviewed, including the classification of metals/alloys, oxides, hydroxides, sulfides, phosphides, selenides, and other transition metal compounds. In addition, the oxygen evolution mechanism and rate-determining steps of transition metal-based catalysts are also discussed. Finally, the advantages, challenges, and opportunities regarding the application of electrochemical techniques in the synthesis of transition metal-based OER electrocatalysts are summarized. This review can provide inspiration for researchers and promote the development of water splitting technology.

New Trends in Nanoarchitectured SERS Substrates: Nanospaces, 2D Materials, and Organic Heterostructures

This article reviews recent fabrication methods for surface-enhanced Raman spectroscopy (SERS) substrates with a focus on advanced nanoarchitecture based on noble metals with special nanospaces (round tips, gaps, and porous spaces), nanolayered 2D materials, including hybridization with metallic nanostructures (NSs), and the contemporary repertoire of nanoarchitecturing with organic molecules. The use of SERS for multidisciplinary applications has been extensively investigated because the considerably enhanced signal intensity enables the detection of a very small number of molecules with molecular fingerprints. Nanoarchitecture strategies for the design of new NSs play a vital role in developing SERS substrates. In this review, recent achievements with respect to the special morphology of metallic NSs are discussed, and future directions are outlined for the development of available NSs with reproducible preparation and well-controlled nanoarchitecture. Nanolayered 2D materials are proposed for SERS applications as an alternative to the noble metals. The modern solutions to existing limitations for their applications are described together with the state-of-the-art in bio/environmental SERS sensing using 2D materials-based composites. To complement the existing toolbox of plasmonic inorganic NSs, hybridization with organic molecules is proposed to improve the stability of NSs and selectivity of SERS sensing by hybridizing with small or large organic molecules.

Plasma-Induced Nanocrystalline Domain Engineering and Surface Passivation in Mesoporous Chalcogenide Semiconductor Thin Films

The synthesis of highly crystalline mesoporous materials is key to realizing high‐performance chemical and biological sensors and optoelectronics. However, minimizing surface oxidation and enhancing the domain size without affecting the porous nanoarchitecture are daunting challenges. Herein, we report a hybrid technique that combines bottom‐up electrochemical growth with top‐down plasma treatment to produce mesoporous semiconductors with large crystalline domain sizes and excellent surface passivation. By passivating unsaturated bonds without incorporating any chemical or physical layers, these films show better stability and enhancement in the optoelectronic properties of mesoporous copper telluride (CuTe) with different pore diameters. These results provide exciting opportunities for the development of long‐term, stable, and high‐performance mesoporous semiconductor materials for future technologies.

Material Nanoarchitectonics of Functional Polymers and Inorganic Nanomaterials for Smart Supercapacitors

Smart supercapacitors are a promising energy storage solution due to their high power density, long cycle life, and low-maintenance requirements. Functional polymers (FPs) and inorganic nanomaterials are used in smart supercapacitors because of the favorable mechanical properties (flexibility and stretchability) of FPs and the energy storage properties of inorganic materials. The complementary properties of these materials facilitate commercial applications of smart supercapacitors in flexible smart wearables, displays, and self-generation, as well as energy storage. Here, an overview of strategies for the development of suitable materials for smart supercapacitors is presented, based on recent literature reports. A range of synthetic techniques are discussed and it is concluded that a combination of organic and inorganic hybrid materials is the best option for realizing smart supercapacitors. This perspective facilitates new strategies for the synthesis of hybrid materials, and the development of material technologies for smart energy storage applications.

Macroscopic MOF Architectures: Effective Strategies for Practical Application in Water Treatment

Metal-organic frameworks (MOFs) have potential applications in removing pollutants such as heavy metals, oils, and toxins from water. However, due to the intrinsic fragility of MOFs and their fine powder form, there are still technical barriers to their practical application such as blockage of pipes, difficulty in recovery, and potential environmental toxicity. Therefore, attention has focused on approaches to convert nanocrystalline MOFs into macroscopic materials to overcome these limitations. Recently, strategies for shaping MOFs into beads (0D), nanofibers (1D), membranes (2D), and gels/sponges (3D) with macrostructures are developed including direct mixing, in situ growth, or deposition of MOFs with polymers, cotton, foams or other porous substrates. In this review, successful strategies for the fabrication of macroscopic materials from MOFs and their applications in removing pollutants from water including adsorption, separation, and advanced oxidation processes, are discussed. The relationship between the macroscopic performance and the microstructure of materials, and how the range of 0D to 3D macroscopic materials can be used for water treatment are also outlined.

Modular Assembly of MOF-derived Carbon Nanofibers into Macroarchitectures for Water Treatment

The organized assembly of nanoparticles into complex macroarchitectures opens up a promising pathway to create functional materials. Here, we demonstrate a scalable strategy to fabricate macroarchitectures with high compressibility and elasticity from hollow particle-based carbon nanofibers. This strategy causes zeolitic imidazolate framework (ZIF-8)-polyacrylonitrile nanofibers to assemble into centimetre-sized aerogels (ZIF-8/NFAs) with expected shapes and tunable functions on a large scale. On further carbonization of ZIF-8/NFAs, ZIF-8 nanoparticles are transformed into a hollow structure to form the carbon nanofiber aerogels (CNFAs). The resulting CNFAs integrate the properties of zero-dimensional hollow structures, one-dimensional nanofibers, and three-dimensional carbon aerogels, and exhibit a low density of 7.32 mg cm⁻³, high mechanical strength (rapid recovery from 80% strain), outstanding adsorption capacity, and excellent photo-thermal conversion potential. These results provide a platform for the future development of macroarchitectured assemblies from nanometres to centimetres and facilitate the design of multifunctional materials.

A scalable strategy is established to generate macroarchitectures based on MOF-related nanofibers. The modular assembly of macroarchitectures with luffa-like structures exhibits high mechanical strength and low densities.

Strategic design of Fe and N co-doped hierarchically porous carbon as superior ORR catalyst: from the perspective of nanoarchitectonics

In this study, we present microporous carbon (MPC), hollow microporous carbon (HMC) and hierarchically porous carbon (HPC) to demonstrate the importance of strategical designing of nanoarchitectures in achieving advanced catalyst (or electrode) materials, especially in the context of oxygen reduction reaction (ORR). Based on the electrochemical impedance spectroscopy and ORR studies, we identify a marked structural effect depending on the porosity. Specifically, mesopores are found to have the most profound influence by significantly improving electrochemical wettability and accessibility. We also identify that macropore contributes to the rate capability of the porous carbons. The results of the rotating ring disk electrode (RRDE) method also demonstrate the advantages of strategically designed double-shelled nanoarchitecture of HPC to increase the overall electron transfer number (n) closer to four by offering a higher chance of the double two-electron pathways. Next, selective doping of highly active Fe–N_x sites on HPC is obtained by increasing the nitrogen content in HPC. As a result, the optimized Fe and N co-doped HPC demonstrate high ORR catalytic activity comparable to the commercial 20 wt% Pt/C in alkaline electrolyte. Our findings, therefore, strongly advocate the importance of a strategic design of advanced catalyst (or electrode) materials, especially in light of both structural and doping effects, from the perspective of nanoarchitectonics.

This study elucidates the role of each class of nanopore by in-depth electrochemical analysis of three types of ZIF-8-derived carbons. Also, engineered co-doping of Fe and N is found essential to selectively form Fe–N_x sites in the carbon matrix.

Progress in Solid Polymer Electrolytes for Lithium-Ion Batteries and Beyond

Solid-state polymer electrolytes (SPEs) for high electrochemical performance lithium-ion batteries have received considerable attention due to their unique characteristics; they are not prone to leakage, and they exhibit low flammability, excellent processability, good flexibility, high safety levels, and superior thermal stability. However, current SPEs are far from commercialization, mainly due to the low ionic conductivity, low Li⁺ transference number (t_Li+ ), poor electrode/electrolyte interface contact, narrow electrochemical oxidation window, and poor long-term stability of Li metal. Recent work on improving electrochemical performance and these aspects of SPEs are summarized systematically here with a particular focus on the underlying mechanisms, and the improvement strategies are also proposed. This review could lead to a deeper consideration of the issues and solutions affecting the application of SPEs and pave a new pathway to safe, high-performance lithium-ion batteries.

Efficient lithium-ion storage using a heterostructured porous carbon framework and its in situ transmission electron microscopy study

A heterostructured porous carbon framework (PCF) composed of reduced graphene oxide (rGO) nanosheets and metal organic framework (MOF)-derived microporous carbon is prepared to investigate its potential use in a lithium-ion battery. As an anode material, the PCF exhibits efficient lithium-ion storage performance with a high reversible specific capacity (771 mA h g^-1 at 50 mA g^-1), an excellent rate capability (448 mA h g^-1 at 1000 mA g^-1), and a long lifespan (75% retention after 400 cycles). The in situ transmission electron microscopy (TEM) study demonstrates that its unique three-dimensional (3D) heterostructure can largely tolerate the volume expansion. We envisage that this work may offer a deeper understanding of the importance of tailored design of anode materials for future lithium-ion batteries.

0D-1D hybrid nanoarchitectonics: tailored design of FeCo@N-C yolk-shell nanoreactors with dual sites for excellent Fenton-like catalysis

Heterogeneous Fenton-like processes are very promising methods of treating organic pollutants through the generation of reactive oxygen containing radicals. Herein, we report novel 0D-1D hybrid nanoarchitectonics (necklace-like structures) consisting of FeCo@N-C yolk-shell nanoreactors as advanced catalysts for Fenton-like reactions. Each FeCo@N-C unit possesses a yolk-shell structure like a nanoreactor, which can accelerate the diffusion of reactive oxygen species and guard the active sites of FeCo. Furthermore, all the nanoreactors are threaded along carbon fibers, providing a highway for electron transport. FeCo@N-C nano-necklaces thereby exhibit excellent performance for pollutant removal via activation of peroxymonosulfate, achieving 100% bisphenol A (k = 0.8308 min^-1) degradation in 10 min with good cycling stability. The experiments and density-functional theory calculations reveal that FeCo dual sites are beneficial for activation of O-O, which is crucial for enhancing Fenton-like processes.

KOH-Activated Hollow ZIF-8 Derived Porous Carbon: Nanoarchitectured Control for Upgraded Capacitive Deionization and Supercapacitor

Herein, the synergistic effects of hollow nanoarchitecture and high specific surface area of hollow activated carbons (HACs) are reported with the superior supercapacitor (SC) and capacitive deionization (CDI) performance. The center of zeolite imidazolate framework-8 (ZIF-8) is selectively etched to create a hollow cavity as a macropore, and the resulting hollow ZIF-8 (HZIF-8) is carbonized to obtain hollow carbon (HC). The distribution of nanopores is, subsequently, optimized by KOH activation to create more nanopores and significantly increase specific surface area. Indeed, as-prepared hollow activated carbons (HACs) show significant improvement not only in the maximum specific capacitance and desalination capacity but also capacitance retention and mean desalination rates in SC and CDI, respectively. As a result, it is confirmed that well-designed nanoarchitecture and porosity are required to allow efficient diffusion and maximum electrosorption of electrolyte ions.

Phenyl-Modified Carbon Nitride Quantum Nanoflakes for Ultra-Highly Selective Sensing of Formic Acid: A Combined Experimental by QCM and Density Functional Theory Study

Formic acid (HCOOH) is an important intermediate in chemical synthesis, pharmaceuticals, the food industry, and leather tanning and is considered to be an effective hydrogen storage molecule. Direct contact with its vapor and its inhalation lead to burns, nerve injury, and dermatosis. Thus, it is critical to establish efficient sensing materials and devices for the rapid detection of HCOOH. In the present study, we introduce a chemical sensor based on a quartz crystal microbalance (QCM) sensor capable of detecting trace amounts of HCOOH. This sensor is composed of colloidal phenyl-terminated carbon nitride (Ph-g-C₃N₄) quantum nanoflakes prepared using a facile solid-state method involving the supramolecular preorganization technology. In contrast to other synthetic methods of modified carbon nitride materials, this approach requires no hard templates, hazardous chemicals, or hydrothermal treatments. Comprehensive characterization and density functional theory (DFT) calculations revealed that the QCM sensor designed and prepared here exhibits enhanced detection sensitivity and selectivity for volatile HCOOH, which originates from chemical and hydrogen-bonding interactions between HCOOH and the surface of Ph-g-C₃N₄. According to DFT results, HCOOH is located close to the cavity of the Ph-g-C₃N₄ unit, with bonding to graphitic carbon and pyridinic nitrogen atoms of the nanoflake. The sensitivity of the Ph-g-C₃N₄-nanoflake-based QCM sensor was found to be the highest (128.99 Hz ppm^-1) of the substances studied, with a limit of detection (LOD) of HCOOH down to a sub-ppm level of 80 ppb. This sensing technology based on phenyl-terminated attached-g-C₃N₄ nanoflakes establishes a simple, low-cost solution to improve the performance of QCM sensors for the effective discrimination of HCOOH, HCHO, and CH₃COOH vapors using smart electronic noses.

Nanoarchitectured Porous Conducting Polymers: From Controlled Synthesis to Advanced Applications

Conductive polymers (CPs) integrate the inherent characteristics of conventional polymers and the unique electrical properties of metals. They have aroused tremendous interest over the last decade owing to their high conductivity, robust and flexible properties, facile fabrication, and cost-effectiveness. Compared to bulk CPs, porous CPs with well-defined nano- or microstructures possess open porous architectures, high specific surface areas, more exposed reactive sites, and remarkably enhanced activities. These attractive features have led to their applications in sensors, energy storage and conversion devices, biomedical devices, and so on. In this review article, the different strategies for synthesizing porous CPs, including template-free and template-based methods, are summarized, and the importance of tuning the morphology and pore structure of porous CPs to optimize their functional performance is highlighted. Moreover, their representative applications (energy storage devices, sensors, biomedical devices, etc.) are also discussed. The review is concluded by discussing the current challenges and future development trend in this field.

Universal Electrochemical Synthesis of Mesoporous Chalcogenide Semiconductors: Mesoporous CdSe and CdTe Thin Films for Optoelectronic Applications

Here we report the soft-template-assisted electrochemical deposition of mesoporous semiconductors (CdSe and CdTe). The resulting mesoporous films are stoichiometrically equivalent and contain mesopores homogeneously distributed over the entire surface. To demonstrate the versatility of the method, two block copolymers with different molecular weights are used, yielding films with pores of either 9 or 18 nm diameter. As a proof of concept, the mesoporous CdSe film-based photodetectors show a high sensitivity of 204 mW^-1  cm² at 680 nm wavelength, which is at least two orders of magnitude more sensitive than the bulk counterpart. This work presents a new synthesis route for nanostructured semiconductors with optical band gaps active in the visible spectrum.

Nanoporous carbon nitride with a high content of inbuilt N site for the CO2 capture

We report the nanoconfinement-mediated graphitic nanoporous carbon nitride (gNPCN) adsorbents with a high content of inbuilt basic nitrogen (N) (48%) by X-ray photoelectron spectroscopy (XPS) for efficient CO₂ adsorption. The gNPCNs (gNPCN-150 and gNPCN-130) are synthesized using the mesoporous SBA-15 silica template and a single carbon-nitrogen (C-N) precursor (guanidine hydrochloride). The various adsorbents were utilized for investigating the influence of pore size (PS), surface area (SA), and type of adsorbent for CO₂ adsorption performance. The capacity for CO₂ capturing of gNPCN-150 reached 23.1 mmol/g at 0 °C under 30 bar pressure. This CO₂ capturing capacity value was higher than the capacity gNPCN-130, SBA15, activated carbon (AC), and multiwalled carbon nanotube (MWCN) under identical conditions. The gNPCN materials exhibited superior CO₂ adsorption ability that is ascribed to the presence of the highly organized mesoporosity, inbuilt high content of basic N site for adsorbing more CO₂ through acid-base interaction, and tunable surface-structural properties. Moreover, the synthesis strategy is remarkably flexible in selecting C-N sources. This study features graphitic high-ordered nanoporous CN materials as a resourceful platform towards the efficient CO₂ capture.

In Search of Excellence: Convex versus Concave Noble Metal Nanostructures for Electrocatalytic Applications

Controlling the shape of noble metal nanoparticles is a challenging but important task in electrocatalysis. Apart from hollow and nanocage structures, concave noble metal nanoparticles are considered a new class of unconventional electrocatalysts that exhibit superior electrocatalytic properties as compared with those of conventional nanoparticles (including convex and flat ones). Herein, several facile and highly reproducible routes for synthesizing nanostructured concave noble metal materials reported in the literature are discussed, together with their advantages over noble metal nanoparticles with convex shapes. In addition, possible ways of optimizing the synthesis procedure and enhancing the electrocatalytic characteristics of concave metal nanoparticles are suggested. Nanostructured noble metals with concave features are found to show better catalytic activity and stability hence improve their practical applicability in electrocatalysis.

Mesoporous gold-silver alloy films towards amplification-free ultra-sensitive microRNA detection

Herein, we report the preparation of mesoporous gold (Au)-silver (Ag) alloy films through the electrochemical micelle assembly process and their applications as microRNA (miRNA) sensors. Following electrochemical deposition and subsequent removal of the templates, the polymeric micelles can create uniformly sized mesoporous architectures with high surface areas. The resulting mesoporous Au-Ag alloy films show high current densities (electrocatalytic activities) towards the redox reaction between potassium ferrocyanide and potassium ferricyanide. Following magnetic isolation and purification, the target miRNA is adsorbed directly on the mesoporous Au-Ag film. Electrochemical detection is then enabled by differential pulse voltammetry (DPV) using the [Fe(CN)6]3-/4- redox system (the faradaic current for the miRNA-adsorbed Au-Ag film decreases compared to the bare film). The films demonstrate great advantages towards miRNA sensing platforms to enhance the detection limit down to attomolar levels of miR-21 (limit of detection (LOD) = 100 aM, s/n = 3). The developed enzymatic amplification-free miniaturized analytical sensor has promising potential for RNA-based diagnosis of diseases.

Nanoarchitectured porous carbons derived from ZIFs toward highly sensitive and selective QCM sensor for hazardous aromatic vapors

Metal-organic frameworks (MOFs) are a versatile source of carbon nanoarchitectures in gas sensing applications (Torad et al., 2019). Herein, several types of nanoporous carbons (NPCs) have been prepared by in-situ carbothermal treatment of zeolitic imidazolate frameworks (ZIFs) under different inert atmospheres to achieve a highly sensitive discrimination of vaporized aromatic compounds. In this study, we demonstrate how different carbonization conditions under the flow of N₂ or H₂ gases affect the surface area and the degree of graphitization of the resulting NPCs polyhedrons, and their consequent effect on the sensing performance in terms of sensitivity and selectivity toward toxic volatile hydrocarbons. A growth of carbon nanotubes (CNTs) is observed on the surface of polyhedral NPCs after careful carbonization of ZIF crystals under H₂ atmosphere. The fabricated quartz crystal microbalance (QCM) sensor with CNT-containing NPCs demonstrates increased sensitivity and selectivity towards toxic volatile aromatic hydrocarbons over the aliphatic analogues, suggesting the rich growth of hairy graphitic-like CNTs on the surface of carbon framework act as highly selective sensing antennae for vapor molecular discrimination of toxic aromatic hydrocarbons. Despite of increased selectivity towards volatile aromatic compounds, however, the surface area of CNT-rich NPCs derived from hybrid ZIFs and ZIF-67 is greatly sacrificed as compared to CNT-free NPCs from ZIF-8 polyhedron. In the case of Co-containing ZIF-67, the rich growth of hair-like CNTs, which is induced by the presence of Co, is observed during carbothermal reduction under a flow of H₂ gas, thus allowing ultra-selective detection of aromatic hydrocarbons in the vapor phase, such as benzene (C₆H₆) and toluene (C₆H₅CH₃) over their aliphatic analogue, c-hexane (c-C₆H₁₂) of same molecular mass, size and vapor pressure.

Enantioselective SERS sensing of pseudoephedrine in blood plasma biomatrix by hierarchical mesoporous Au films coated with a homochiral MOF

Here, we present a new family of hierarchical porous hybrid materials as an innovative tool for ultrasensitive and selective sensing of enantiomeric drugs in complex biosamples via chiral surface-enhanced Raman spectroscopy (SERS). Hierarchical porous hybrid films were prepared by the combination of mesoporous plasmonic Au films and microporous homochiral metal-organic frameworks (HMOFs). The proposed hierarchical porous substrates enable extremely low limit of detection values (10^-12 M) for pseudoephedrine in undiluted blood plasma due to dual enhancement mechanisms (physical enhancement by the mesoporous Au nanostructures and chemical enhancement by HMOF), chemical recognition by HMOF, and a discriminant function for bio-samples containing large biomolecules, such as blood components. We demonstrate the effect of each component (mesoporous Au and microporous AlaZnCl (HMOF)) on the analytical performance for sensing. The growth of AlaZnCl leads to an increase in the SERS signal (by around 17 times), while the use of mesoporous Au leads to an increase in the signal (by up to 40%). In the presence of a complex biomatrix (blood serum or plasma), the hybrid hierarchical porous substrate provides control over the transport of the molecules inside the pores and prevents blood protein infiltration, provoking competition with existing plasmonic materials at the limit of detection and enantioselectivity in the presence of a multicomponent biomatrix.

Conversion of agricultural waste into stable biocrude using spinel oxide catalysts

Biomass, the feedstock for biocrude and ultimately renewable diesel is a low energy density feedstock. The transport of this feedstock over long distance has been proven to be a major burden on the commercialisation of biorefining. Therefore, it has been generally accepted that biomass should be upgraded to biocrude (a relatively high energy density liquid) in close proximity to the biomass sources. The biocrude liquid would then be transported to a biorefinery. Biocrude contains large amounts of oxygen (generally up to 38 wt%) that is removed from the crude in the refining process. In this study, we have synthesised a range of spinel oxide based catalysts to remove oxygen from the biocrude during the catalytic fast pyrolysis. The activity of spinel oxide (MgB₂O₄ where B = Fe, Al, Cr, Ga, La, Y, In) catalysts were screened for the pyrolysis reaction. While all the tested spinel oxides deoxygenated the pyrolysis vapour, MgCr₂O₄ was found to be effective in terms of oxygen removal efficiency relative to the quantity of bio oil produced.

Highly dispersed secondary building unit-stabilized binary metal center on a hierarchical porous carbon matrix for enhanced oxygen evolution reaction

Restricting the aggregation and rationally adjusting the electronic structure of binary metal centers in metal-organic framework (MOF) precursors are important for optimizing their performance as electrocatalysts for the oxygen evolution reaction (OER) and achieving low overpotential and high stability in such applications. Herein, we demonstrate the possibility of enhancing the electrochemical activity of MOF-derived binary metal center catalysts by controlling the form of the Fe species. The introduction of Fe-SBU (iron 2,5-dihydroxyterephthalic acid) into ZIF-67 is found to induce a distinct confinement effect and this can be exploited to improve the electroconductivity of binary metal center catalysts, and therefore, to reduce the OER reaction barrier (OOH* → O*). When applied as an OER catalyst in 1 M KOH solution, the Fe-SBU@Co-Matrix catalyst exhibits a low overpotential of 249 mV to reach a current density of 10 mA cm^-2 and high stability for over 40 h. This work describes the secondary growth treatment of MOF-derived porous carbons to promote their application as catalysts in energy conversion reactions.

Metal-incorporated mesoporous oxides: Synthesis and applications

Mesoporous oxides are outstanding metal nanoparticle catalyst supports owing to their well-defined porous structures. Such mesoporous architectures not only prevent the aggregation of metal nanoparticles but also enhance their catalytic performance. Metal/metal oxide heterojunctions exhibit unique chemical and physical properties because of the surface reconstruction around the junction and electron transfer/interaction across the interface. This article reviews the methods used for synthesizing metal-supported hybrid nanostructures and their applications as catalysts for environmental remediation and sensors for detecting hazardous materials.

Hollow Carbon-Based Nanoarchitectures Based on ZIF: Inward/Outward Contraction Mechanism and Beyond

Hollow carbon-based nanoarchitectures (HCAs) derived from zeolitic imidazolate frameworks (ZIFs), by virtue of their controllable morphology and dimension, high specific surface area and nitrogen content, richness of metal/metal compounds active sites, and hierarchical pore structure and easy exposure of active sites, have attracted great interests in many fields of applications, especially in heterogeneous catalysis, and electrochemical energy storage and conversion. Despite various approaches that have been developed to prepare ZIF-derived HCAs, the hollowing mechanism has not been clearly disclosed. Herein, a specialized overview of the recent progress of ZIF-derived HCAs is introduced to provide an insight into their preparation strategy and the corresponding hollowing mechanisms. Based on the fundamental understanding of the structural evolution of ZIF nanocrystals during the high-temperature pyrolysis process, the hollowing mechanisms of ZIF-derived HCAs are classified into four categories: i) inward contraction of core-shell template@ZIF composites or hollow ZIFs, ii) outward contraction of ZIF@shell composites, iii) special outward contraction of ZIF arrays, and iv) mechanism beyond inward/outward contraction of pure ZIF nanocrystals. Finally, an outlook on the development prospects and challenges of HCAs based on ZIF precursors, especially in terms of controlled synthesis and future electrochemical application, is further discussed.

Amorphous Alloy Architectures in Pore Walls: Mesoporous Amorphous NiCoB Alloy Spheres with Controlled Compositions via a Chemical Reduction

Amorphous bimetallic borides are an emerging class of catalytic nanomaterial that has demonstrated excellent catalytic performance due to its glass-like structure, abundant unsaturated active sites, and synergistic electronic effects. However, the creation of mesoporous Earth-abundant bimetallic metal borides with tunable metal proportion remains a challenge. Herein, we develop a sophisticated and controllable dual-reducing agent strategy to synthesize the mesoporous nickel-cobalt boron (NiCoB) amorphous alloy spheres (AASs) with adjustable compositions by using a soft template-directed assembly approach. The selective use of tetrabutylphosphonium bromide (Bu₄PBr) is beneficial to generate well-defined mesopores because it both moderates the reduction rate by decreasing the reducibility of M²⁺ species and prevents the generation of soap bubbles. Our meso-Ni_10.0Co_74.5B_15.5 AASs generate the highest catalytic performance for the hydrolytic dehydrogenation of ammonia borane (AB). Its high performance is attributed to the combination of optimal synergistic effects between Ni, Co, and B as well as the high surface area and the good mass transport efficiency due to the open mesopores. This work describes a systematic approach for the design and synthesis of mesoporous bimetallic borides as efficient catalysts.

Tunable Concave Surface Features of Mesoporous Palladium Nanocrystals Prepared from Supramolecular Micellar Templates

Concave metallic nanocrystals with a high density of low-coordinated atoms on the surface are essential for the realization of unique catalytic properties. Herein, mesoporous palladium nanocrystals (MPNs) that possess various degrees of curvature are successfully synthesized following an approach that relies on a facile polymeric micelle assembly approach. The as-prepared MPNs exhibit larger surface areas compared to conventional Pd nanocrystals and their nonporous counterparts. The MPNs display enhanced electrocatalytic activity for ethanol oxidation when compared to state-of-the-art commercial palladium black and conventional palladium nanocubes used as catalysts. Interestingly, as the degree of curvature increases, the surface-area-normalized activity also increases, demonstrating that the curvature of MPNs and the presence of high-index facets are crucial considerations for the design of electrocatalysts.

[Clinical analysis of children with cardiac syncope caused by anomalous origin of the left coronary artery from the right sinus]

Objective: To analysis the clinical characteristics and to summarize therapy experience of pediatric patients with cardiac syncope caused by anomalous origin of the left coronary artery from the right sinus (ALCA-R). Methods: We retrospectively analyzed the clinical data including clinical manifestations, myocardial injury biomarkers, radiological features, treatments and prognoses of pediatric patients with ALCA-R who were admitted to Beijing Children's Hospital from November 2015 to June 2018. Results: Four female patients were included in this analysis, age of onset was 7 to 14 years. All the patients presented with exercise-induced syncope and acute myocardial infarction. During the course, three patients presented with acute left heart failure, and one patient had history of sudden cardiac arrest. Laboratory data showed significant elevation of both the creatine kinase and troponin levels in four patients. All electrocardiogram (ECG) showed left main coronary artery occlusion, echocardiography suggested the possible anomalous origin of the left coronary artery in one child. Coronary CT angiography (CTA) revealed there was no coronary ostium in the left coronary sinus, and the left coronary artery had an anomalous origin from the right sinus. The left main coronary artery passed between the ascending artery and the root of the main pulmonary artery, which was compressed by these two large vessels. Two patients underwent cardiac magnetic resonance examination, which detected late gadolinium enhancement in ALCA-R with an interarterial course. Unroofing of the left coronary ostium (cut-back procedure) was performed in two patients, and the other two patients who were not operated were recommended to restrict their physical activities. During a regular follow-up period of 12-43 months, all the children survived without recurrent cardiovascular event. Conclusion: If an adolescent presents with exercise-induced syncope, acute myocardial infarction and even sudden death, and ECG shows left main coronary artery occlusion characteristics, we should consider the possibility of developmental abnormality of coronary artery, particularly the ALCA-R. Once diagnosed as ALCA-R, patients should be recommended to avoid strenuous activities，early recognition and surgical treatment are imperative for these patients.

Electrochemical Synthesis of Mesoporous Architectured Ru Films Using Supramolecular Templates

The electrochemical synthesis of mesoporous ruthenium (Ru) films using sacrificial self-assembled block polymer micelles templates, and its electrochemical surface oxidation to RuO_x is described. Unlike standard methods such as thermal oxidation, the electrochemical oxidation method described here retains the mesoporous structure. Ru oxide materials serve as high-performance supercapacitor electrodes due to their excellent pseudocapacitive behavior. The mesoporous architectured film shows superior specific capacitance (467 F g^-1_Ru ) versus a nonporous Ru/RuO_x electrode (28 F g^-1_Ru ) that is prepared via the same method but omitting the pore-directing polymer. Ultrahigh surface area materials will play an essential role in increasing the capacitance of this class of energy storage devices because the pseudocapacitive redox reaction occurs on the surface of electrodes.

Tailored Nanoarchitecturing of Microporous ZIF-8 to Hierarchically Porous Double-Shell Carbons and Their Intrinsic Electrochemical Property

Mesostructured polydopamine (PDA) coating has been successfully achieved on the surface of zeolitic imidazolate framework-8 (ZIF-8) particles by incorporating Pluronic F127 (with a pore-expanding agent, 1,3,5-trimethylbenzene) as a pore-directing agent during dopamine polymerization. Upon pyrolysis at high temperatures, mesostructured PDA-coated ZIF-8 particles become hierarchically porous double-shell carbons (HPDCs) with a wide pore size distribution ranging from micro- and meso- to macropores. The formation of a hollow inner shell progresses initially with the shrinkage of ZIF-8 at the periphery where the interface interactions with mesostructured PDA exist, and then the subsequent disintegration of the ZIF-8 core at higher temperatures occurs. Our HPDCs prepared in this study feature physical and electrochemical advantages of hierarchically porous carbons such as high electrochemically accessible surface area, short diffusion distance, and high mass-transfer rate, thus demonstrating significantly improved ion diffusion and surface-enhanced high specific capacitance at high charge-discharge rates. HPDC_5.0 therefore exhibits the capacitance retention of up to 76.7% from 1 to 10 A g^-1 and maximum specific capacitance of 344.7 F g^-1 at 1 mV s^-1. It also possesses superior electrochemical stability with about 108% capacitance retention even after 10,000 consecutive cycles of galvanostatic charge-discharge at 10 A g^-1.

Magnetic nanocellulose: A potential material for removal of dye from water

In this study, cellulose nanofibers are used as a template to synthesise magnetic nanoparticles with a uniform size distribution. Magnetic nanoparticles are grafted on the surface of nanofibers via in situ hydrolysis of metal precursors at room temperature. Effects of different concentrations of nanofibers on the morphology, the crystallite size of magnetic nanoparticles, and the thermal and magnetic properties of the membrane produced from the cellulose nanofibers decorated with magnetic nanoparticles are examined. The sizes of magnetic nanoparticles produced in this study are below 20 nm, and the crystallite size of the nanoparticles is in the range of 96-130 Å. The flexible magnetic membranes containing a high concentration of magnetic nanoparticles (83-60 wt%) showed superparamagnetic behaviour with very high magnetic properties (67.4-38.5 emu g^-1). The magnetic membrane was then used as an environmentally friendly, low-cost catalyst in a sulphate radical-based advanced oxidation process. The membranes successfully activated peroxymonosulphate (PMS) to remove Rhodamine B (RhB), a common hydrophilic organic dye applied in industry. 94.9 % of the Rhodamine B was degraded in 300 min at room temperature, indicating that the magnetic nanocellulose membrane is highly effective for catalyzing PMS to remove RhB.

Non-precious molybdenum nanospheres as a novel cocatalyst for full-spectrum-driven photocatalytic CO2 reforming to CH4

Photocatalytic CO₂ reforming is considered to be an effective method for clean, low-cost, and environmentally friendly reduction and conversion of CO₂ into hydrocarbon fuels by utilizing solar energy. However, the low separation efficiency of charge carriers and deficient reactive sites have severely hampered the efficiency of the photocatalytic CO₂ reforming process. Therefore, cocatalysts are usually loaded onto the surface of semiconductor photocatalysts to reduce the recombination of charge carriers and accelerate the rates of surface reactions. Herein, molybdenum (Mo) nanospheres are proposed as a novel non-precious cocatalyst to enhance the photocatalytic CO₂ reforming of g-C₃N₄ significantly. The Mo nanospheres boost the adsorption of CO₂ and activate the surface CO₂via a photothermal effect. The time-resolved fluorescence decay spectra reveals that the lifetime of photo-induced charge carriers is prolonged by the Mo nanospheres, which guarantees the migration of charge carriers from g-C₃N₄ to Mo nanospheres. Unexpectedly, Mo loaded g-C₃N₄ can effectively utilize a wide spectral range from UV to near-infrared region (NIR, up to 800 nm). These findings highlight the potential of Mo nanospheres as a novel cocatalyst for photocatalytic CO₂ reforming to CH₄.

Significant Improvement in Electrical Conductivity and Figure of Merit of Nanoarchitectured Porous SrTiO3 by La Doping Optimization

SrTiO₃ is a well-studied n-type metal oxide based thermoelectric (TE) material. In this work, the first-principles calculation of La-doped SrTiO₃ has been performed using the density functional theory. In addition, high TE properties of bulk SrTiO₃ material have been achieved by introducing nanoscale porosity and optimizing carrier concentration by La doping. The X-ray diffraction, atomic resolution scanning transmission electron microscopy imaging, and energy-dispersive X-ray spectrometry results show that La has been doped successfully into the lattice. The scanning electron microscopy images confirm that all the samples have nearly similar nanoscale porosities. The significant enhancement of electrical conductivity over the broad temperature range has been observed through optimization of La doping. Additionally, the samples possess very low thermal conductivity, which is speculated because of the nanoscale porosity of the samples. Because of this dual mechanism of doping optimization and nanoscale porosity, there is a remarkable improvement in power factor, 1 mW/m²K from 650 to 800 K, and figure of merit, zT of 0.26 at 850 K, of the sample, 22 at. % La-doped SrTiO₃.

Layer-by-Layer Motif Heteroarchitecturing of N,S-Codoped Reduced Graphene Oxide-Wrapped Ni/NiS Nanoparticles for the Electrochemical Oxidation of Water

A new heterostructured material is synthesized with lamellar arrangements in nanoscale precision through an innovative synthetic approach. The self-assembled Ni-based cyano-bridged coordination polymer flakes (Ni-CP) and graphene oxide (GO) nanosheets with a layered morphology (Ni-CP/GO) are used as precursors for the synthesis of multicomponent hybrid materials. Annealing of Ni-CP/GO in nitrogen at 450 °C allows the formation of Ni₃ C/rGO nanocomposites. Grinding Ni-CP/GO and thiourea and annealing under the same conditions produces N,S-codoped reduced GO-wrapped NiS₂ flakes (NiS₂ /NS-rGO). Interestingly, further heating up to 550 °C allows the phase transformation of NiS₂ into NiS accompanied by the formation of a face-centered cubic (FCC-Ni) metal phase between NS-rGO layers (FCC-Ni-NiS/NS-rGO). Among all the materials, the resulting FCC-Ni-NiS/NS-rGO exhibits good electrocatalytic activity and stability toward the oxygen evolution reaction (OER) owing to the synergistic effect of multiphases, the well-designed alternating layered structures on the nanoscale with abundant active sites.