Facile Method Research Articles

Research on the Evaluation of an Age-Friendly Layout of Medical Service Facilities in Wuhan City Based on Accessibility

Accessibility is an important indicator for measuring the level of medical facility services in cities. Traditional studies on healthcare accessibility for the elderly have typically focused on the capabilities of emergency services while overlooking the daily independent healthcare needs of the elderly. Taking Wuhan City as an example, the Gaussian two-step floating catchment area method is used in this study to measure the accessibility of urban elderly residents with respect to general hospitals, specialized hospitals, and community health service centers. It also analyzes the appropriateness of the medical facility layout for the elderly in Wuhan City. The research findings indicate the following: (1) The accessibility evaluation method for urban medical facilities established with the Gaussian two-step floating catchment area model can accurately assess the supply–demand relationship between the elderly and various levels of medical facilities. (2) The overall coverage of medical service facilities in Wuhan City is relatively high, but there are significant differences in accessibility for elderly residents in different areas. (3) The appropriateness of daily healthcare access for elderly residents in the central urban areas of Wuhan City is mainly influenced by the layout of general hospitals, while, in the peripheral areas, it is mainly influenced by the layout of specialized hospitals and community health service centers. (4) Improving the appropriateness of urban medical facilities for elderly individuals requires differentiated improvement measures tailored to the characteristics of different zones.

Facile Synthesis of a Layered Bismuth-Based MOF With Superhydrophobic-Oleophilic Property and High Oil-Water Separation Performance.

Metal organic frameworks (MOFs) are a class of potential superhydrophobic-oleophilic materials. The organic ligands in superhydrophobic MOFs usually contain long alkyl chains, fluorine groups or aromatic rings with large π conjugation, the preparation of which suffers from high cost, complex operation and so on. In addition, the topological structure of MOFs plays an important role in the hydrophobicity, which may be ignored previously. Here we report a superhydrophobic-oleophilic MOF (BiPPA2) obtained by a facile and fast method, which not only displays a large water contact angle of up to 163° and a small sliding angle of nearly equal to 0°, but also exhibits high sorption capacity for multiple oils and organic solvents, well reusability and high oil retention. In addition, BiPPA2 is stable in a wide pH range (0.5-11.0). Finally, the single crystal structure of BiPPA2 is resolved to reveal the intrinsic reason for the super-hydrophobicity. This work may inspire the further design of pristine superhydrophobic MOFs based on a simple method, which enriches the family of superhydrophobic MOFs and has great significance for practical applications.

Heterovalent State and Oxygen Vacancy Defect Structure‐Associated V/S Co‐Doped SnO2 for Catalytic Reduction of Organic and Cr6+ Pollutants in the Dark

AbstractV/S co‐doped SnO2 bimetal sulfur‐oxides catalysts labeled as (Sn,V)1‐x(S,O)2‐y or (SnVSO) with heterovalent state and oxygen vacancy defect are prepared via a green and facile method. The presence of SnVSO in the heterovalent states of Sn4+/Sn2+ and V5+/V4+ facilitates the rapid transfer of the electrons. It improves the electronic charge lifetime, accelerating the efficiency of the catalytic reduction of pollutants. The V/S co‐doped SnO2 regulates the bandgap energy structure. The hydrazine adjusts the heterovalent metal states to reduce Sn4+ to Sn2+ and V5+ to V4+. Also, it introduces oxygen vacancies to SnVSO to maintain the charge equilibrium and increase the active surface reactive sites, which enhance the catalytic activity. The SnVSO‐3 prepared with 0.4 mL hydrazine exhibits excellent catalytic activity, which wholly reduces 20 ppm of 100 mL methyl orange (MO), rhodamine B (RhB), methylene blue (MB), hexavalent chromium (Cr6+), and 4‐nitrophenol (4‐NP) within 6 min. In addition, the SnVSO‐3 also has good stability after repeated 6 runs with a reduction efficiency of 96.8%. Therefore, the V/S co‐doped SnO2 sulfur oxide catalysts have a promising potential for reducing Cr6+ and organic pollutants.

Metal-Free Wet Chemistry for the Fast Gram-Scale Synthesis of γ-Graphyne and its Derivatives.

γ-Graphyne (GY), an emerging carbon allotrope, is envisioned to offer various alluring properties and broad applicability. While significant progress has been made in the synthesis of GY over recent decades, its widespread application hinges on developing efficient, scalable, and accessible synthetic methods for the production of GY and its derivatives. Here we report a facile metal-free nucleophilic crosslinking method using wet chemistry for fast gram-scale production of GY and its derivatives. This synthesis method involves the aromatic nucleophilic substitution reactions between fluoro-(hetero)arenes and alkynyl silanes in the presence of a catalytic amount of tetrabutylammonium fluoride, where the fluoride plays a crucial role in removing protective groups from alkynyl silanes and generating reactive alkynylides. Our comprehensive analysis of the as-prepared GY reveals a layered structure, characterized by the presence of the C(sp)-C(sp2) bond. The synthetic strategy shows remarkable tolerance to various functional groups and enables the preparation of diverse F-/N-rich GY derivatives, using electron-deficient fluoro-substituted (hetero)arenes as precursors. The feasibility of producing GY and derivatives from fluorinated (hetero)arenes through the metal-free, scalable, and cost-effective approach paves the way for broad applications of GY and may inspire the development of new carbon materials.

Scalable and Sustainable Zinc (II) Ions‐Glue‐Assisted Conversion of Biomass Waste Bits into Carbon Aerogels for Efficient Uranium Extraction

AbstractCarbon aerogels (CAs) have garnered significant attention due to their multifunctional applications. Biomass waste, abundantly generated by agriculture and industry, serves as a primary carbon source. However, developing a facile, sustainable, and efficient method to produce CAs from biomass waste remains challenging. In this study, a one‐step Zn2+ ion‐glue‐assisted carbonization technique was developed to produce large‐scale, high‐performance CAs. Various biomass materials (wood bits, peanut shells, bamboo bits, and straw waste) were treated in a molten salt system (ZnCl2/KCl) at 300 °C for 2 h to obtain large‐block CAs derived from biomass bits. Zn2+ ions cleave cellulose hydrogen bonds in natural biomass, facilitating the dehydration crosslinking reaction among cellulose, hemicellulose, and lignin, thus reconstructing the entire block structure. The resulting CAs exhibited high porosity (95 %) and low density (0.078 g/cm3). Numerous hydroxyl and carbonyl groups were preserved during the low‐temperature treatment, facilitating chemical modification for diverse applications. For instance, amidoxime functionalized CAs were utilized as filters for selective and highly efficient extraction of U(VI) from wastewater. The adsorption capacity and extraction efficiency reached 801.2 mg/g and 95 % with a flux rate of 6.1×103 L/m2 ⋅ h.

Scalable and Sustainable Zinc (II) Ions Glue Assisted Conversion of Biomass Waste Bits into Carbon Aerogels for Efficient Uranium Extraction.

Carbon aerogels (CAs) are attracting great attention for their multifunctional applications. Additionally, a large amount of biomass bits waste generated from agriculture and industry is regarded as the main carbon resource. However, the development of a facile, sustainable, and efficient method to produce CAs from biomass waste remains challenging. Here, a one-step Zn2+ ions glue triggered carbonization technology was reported to construct large-scale and high-performance CAs. Multiple biomass bits (wood bits, peanut shells, bamboo bits, and straw waste) were treated in the molten salt system (ZnCl2/KCl) at 300 °C for 2h to obtain large-block biomass bits derived CAs. Zn2+ ions as the glue cleavage cellulose hydrogen bonds of natural biomass, then facilitate dehydration crosslinking reaction between cellulose, hemicellulose, and lignin for re-constructing the whole block structure. The obtained CAs show high porosity (95%) and low density (0.078 g/cm3). Meanwhile, numerous of hydroxyl and carbonyl groups were well maintained during low temperature treated process, which facilitate chemical modification for various applications. For instance, amidoxime functionalized CAs were utilized as a filter for selective and highly efficient extraction of U(VI) from wastewater. The adsorption capacity and extraction efficiency reached 801.2 mg/g and 95% with a flux rate of 6.1×103 L/m2·h, respectively.

MoS2_CNTs_aerogel-based PEDOT nanocomposite electrochemical sensor for simultaneous detection of chloramphenicol and furazolidone in food samples

Toxic intermediates in food caused by chloramphenicol (CP) and furazolidone (FZ) have gained interest in research toward their detection. Hence, fast, reliable, and accurate detection of CP and FZ in food products is of utmost importance. Here, a novel molybdenum disulfide-connected carbon nanotube aerogel/poly (3,4-ethylenedioxythiophene) [MoS2/CNTs aerogel/PEDOT] nanocomposite materials are constructed and deposited on the pretreated carbon paste electrode (PCPE) by a facile eletropolymerization method. The characterization of MoS2/CNTs aerogel/PEDOT nanocomposite was analyzed by scanning electron microscopy (SEM), cyclic voltammetry, and differential pulse voltammetry. The modified MoS2/CNTs aerogel/PEDOT nanocomposite has improved sensing characteristics for detecting CP and FZ in PBS solution. For this work, we have studied various parameters like electrocatalytic activity, the effect of scan rates, pH variation studies, and concentration variation studies. Under optimum conditions, the modified electrode exhibited superior sensing ability compared to the bare and pretreated CPE. This improvement in electrocatalytic activity can be the higher conductivity, larger surface area, increased heterogeneous rate constant, and presence of more active sites in the MoS2/CNTs aerogel/PEDOT nanocomposite. The modified electrode demonstrated distinct electrochemical sensing toward the individual and simultaneous analysis of CP and FZ with a high sensitivity of 0.701 µA. µM−1 .cm−2 for CP and 0.787 µA. µM−1 .cm−2 for FZ and a low detection limit of 3.74 nM for CP and 3.83 nM for FZ with good reproducibility, repeatability, and interferences. Additionally, the prepared sensor effectively detects CP and FZ in food samples (honey and milk) with an acceptable recovery range and a relative standard deviation below 4%.

Single glass and polymer coated phosphate glass microwire photoactuators with instant response times and large actuating angles

Over the years significant scientific attention has been given towards the design of advanced photoactuating architectures as they are important elements for various optical tweezers, grippers, and soft robot applications. Most of the currently available photoactuators, rely on the existence of a free-space illumination pathway from the light sources to the device or on the employment of bendable optical fibers, while consisting of two or more elements, i.e. the photoactuating material and the substrate. Herein, we report on a facile method of preparing single-component pristine microwires (MWs) that exhibit photoactuating features upon utilizing a soft phosphate glass doped with silver nanoparticles (AgNPs), without the need of any additional photoactuating element. The developed photoactuators exhibited bending angles of around 110°, within a couple of seconds. In addition, we have fabricated double-component polymer-coated phosphate glass MWs photoactuators, upon employing PDMS coatings on the surface of the so-formed glass MWs. The introduction of the polymer component boosts the bending angle of the photoactuating device to over 200° within the a few seconds upon modest laser irradiation. The presence of AgNPs within the glass MWs, play a key role on the remarkable performance of the developed photoactuators, both in terms of actuating angles as well as of the respective response times, since they assist on the effective transmission of laser irradiation energy to thermal energy. The fabrication method reported here appears promising for the development of high-performance and low-cost free-space, as well as fiber-based photoactuators.

Fabrication of highly thermally conductive and irradiation resistant UHMWPE-based composites for nuclear shielding applications

With the advancement of nuclear energy, the safety of both humans and the surrounding environment necessitates the adoption of effective nuclear radiation shielding materials. Polymer-based shielding materials have garnered attention due to their lightweightness and ease of moldability. However, they normally possess low thermal conductivity (λ) and easy deformation at high temperatures, which potentially cause catastrophic disasters during service if they are mechanically failed due to heat accumulation. To address the above concerns, highly thermally conductive and irradiation resistant ultra-high molecular weight polyethylene (UHMWPE)-based composites were fabricated. Planar fillers such as boron nitride (BN) and graphite (Gt) along with lead (Pb) powders were employed to construct a densely packed filler network for improving the λ and mechanical properties of UHMWPE-based composites. The λ was increased from 3.81 to 6.20 W/mK when 20 wt% Pb (2.88 vol%) was added to BN30/Gt20 (i.e., UHMWPE composite with 30 wt% BN and 20 wt% Gt), representing an increase of 62.73 %. Moreover, the λ of Pb80 was increased from 0.87 to 3.29 W/mK by merely adding 5 wt% (9.99 vol%) Gt, representing a remarkable increase of 278.16 %. GEANT4 simulation results indicated that BN30/Gt20/Pb20 exhibited excellent neutron shielding performance. Samples which were irradiated using 60Co γ-rays at a total dosage of 1.15×105 Gy exhibited enhanced mechanical performance, which indicated excellent irradiation resistance of UHMWPE-based composites. Therefore, a facile method was proposed to prepare multi-functional UHMWPE-based composites that demonstrate promising application in nuclear sectors.

MRSA Inhibitory Activity of Some New Pyrazolo[1,5-a]pyrimidines Linked to Arene and/or Furan or Thiophene Units.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major contributor to hospital-acquired infections and is highly resistant to treatment. Ongoing research focuses on developing new antimicrobial medications to prevent the spread of resistance. A facile method was employed to efficiently synthesize new pyrazolo[1,5-a]pyrimidines in 84-93% yields by reacting 4-benzyl-1H-pyrazole-3,5-diamine with the respective α,β-unsaturated ketones. The reaction was carried out in ethanol containing 1.2 equivalents of potassium hydroxide at reflux for 5-6 h. The new products are attached to a para-substituted aryl group with variable electronic properties at pyrazolopyrimidine-C5, in addition to one of three units at C7, namely phenyl, thiophen-2-yl, or furan-2-yl units. A wide spectrum of antibacterial activity was displayed by the new pyrimidines against six different bacterial strains. In general, pyrimidines attached to furan-2-yl units at C7, in addition to another aryl unit at C5, attached to 4-Me or 4-OMe groups, demonstrate significant antibacterial activity, particularly against S. aureus strain. They had MIC/MBC of 2.5/5.1 and 2.4/4.9 µM, respectively, which exceeded that of ciprofloxacin. Moreover, they demonstrate more effective MRSA inhibitory activity than linezolid, with MIC/MBC values up to 4.9/19.7 and 2.4/19.7 µM against MRSA ATCC:33591 and ATCC:43300 strains, respectively.

In situ-grown nitrogen-sulfur co-doped carbon nanotubes encapsulated with FeS particles as cathode materials for zinc-air batteries

Transition metal sulfides as ideal oxygen reduction reaction (ORR) catalysts have great potential to regulate multiple reaction pathways and understand their corresponding internal reaction mechanisms at cathode in zinc-air batteries (ZABS), effectively. This work adopted a facile one-pot synthesis method based on chemical vapor deposition (CVD), which utilizes the synergistic effect of zeolite imidazolium ester skeleton (ZIF-8) and polypyrrole (PPY) to grow nitrogen-sulfur co-doped carbon nanotubes (NS-CNT) in the shape of colonic with a relatively uniform size and encapsulated with FeS nanoparticles as the main active sites. The synthesized purpose catalyst noted as FeS-NS-CNT-900, in which that the FeS nanoparticles were tightly encapsulated in carbon nanotubes, and this special structure ensures that the FeS particles do not detach during the reaction, thus greatly enhancing their electrochemical activity and stability. As expected, the FeS-NS-CNT-900 catalyst exhibited a half-wave potential of 0.877 V which is higher than that of commercial platinum charcoal (0.847 V), at 0.1 mol KOH. More importantly, the formation of abundant FeS catalytic active sites, the optimal conditions for NS-CNT growth, and the covered mechanisms of the enhanced ORR reaction activity of FeS-NS-CNT-900 were thoroughly investigated. Additionally, whileFeS-NS-CNT-900 was used as an air cathode material for the assembly of a zinc-air battery, it exhibited a peak power density and specific capacity of 123 mW cm−2 and 785.81 mA h g−1, respectively, which were significantly better than that of platinum-carbon cathode (92.8 mW cm−2 and 740.4 mA h g−1). And surprisingly, the battery with FeS-NS-CNT-900 cathode exhibited (delivered/showed) a high cycle stability of 260 h at 5 mA cm−2. Conclusively, present work provides a feasible method for in situ growth of sulfur and nitrogen co-doped carbon nanotube encapsulated transition metal sulfide nanoparticle catalysts, which may pave a new avenue for the preparation of high ORR performance air cathode material for ZABS.

Manipulation in local coordination of platinum single atom enables ultrahigh mass activity toward hydrogen evolution reaction

Atomic-engineering of noble metal into single-atom electrocatalysts with well-defined active sites has been considered as an effective approach to enhance the mass-activity towards hydrogen evolution reaction (HER), crucial for the practical implementation of this sustainable technology. Herein, we devise a metallic-coordination strategy via a facile one-step pyrolysis method, for the atomic isolation of a small amount of platinum (Pt, 0.45 wt%) atoms in the surface of nickel (Ni) nanoparticles (Pt1@Ni) encapsulated into nitrogen-doped carbon nanotubes (Pt1@Ni/NCNT). Such a Pt1@Ni/NCNT single-atom alloy catalyst exhibits a record-high and all-round superior HER performance including mass-activity (up to 350.7 A mgPt−1@η150), stability (>50 h at 100 mA cm−2), pH-tolerance by comparison with Pt1@NC. Our density functional theory calculations combined with in situ Raman spectroscopic studies reveal a synergistic dual-active-site catalytic mechanism, involving the fast hydrogen spillover effect on coordinated Ni supports and accelerated water dissociation in acidic and alkaline medium, respectively. A strong electronic hybridization of 5d orbital of alloyed Pt and 3d orbital of Ni atoms modulates the d band center of Pt, which not only boosts HER activity but also stabilizes Pt single atoms. Due to the double protecting strategy from strong anchoring effect in Ni support and chemically stable NCNT shell, a robust stability is achieved for Pt1@Ni/NCNT hierarchal catalyst. Our findings open up a new avenue to substantially tailor the activity of surface Pt atoms for the design of highly efficient and durable noble metal-based catalysts.

Enhanced Antibacterial Activity of Carbon Dots: A Hybrid Approach with Levofloxacin, Curcumin, and Tea Polyphenols

Bacterial infections and their increasing resistance to antibiotics pose a significant challenge in medical treatment. This study presents the synthesis and characterization of novel carbon dots (CDs) using levofloxacin (Lf), curcumin (Cur), and tea polyphenols (TP) through a facile hydrothermal method. The synthesized curcumin-tea polyphenol@carbon dots (Cur-TP@CDs) and levofloxacin-tea polyphenol@carbon dots (Lf-TP@CDs) were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, confirming their unique structural and chemical properties. Cur-TP@CDs exhibited an average particle size of 1.32 nanometers (nm), while Lf-TP@CDs averaged 1.58 nm. Both types demonstrated significant antibacterial activity, with Lf-TP@CDs showing superior effectiveness against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in broth dilution and disc diffusion assays. Biofilm inhibition assays revealed a significant reduction in biofilm formation at higher concentrations. The ultraviolet-visible (UV-vis) and photoluminescence (PL) spectral analyses indicated efficient photon emission, and electron paramagnetic resonance (EPR) analysis showed increased singlet oxygen generation, enhancing bactericidal effects. Live and dead bacterial staining followed by scanning electron microscopy (SEM) analysis confirmed dose-dependent bacterial cell damage and morphological deformities. These findings suggest that Cur-TP@CDs and Lf-TP@CDs are promising antibacterial agents, potentially offering a novel approach to combat antibiotic-resistant bacterial infections.

Titanium nitride@nitrogen-doped carbon nanocage composites as high-performance cathodes for aqueous Zn-ion hybrid supercapacitors

Aqueous Zn-ion hybrid supercapacitors (AZHSCs) pertain to a new type of electrochemical energy storage device that has received considerable attention. They integrate the advantages of high-energy Zn-ion batteries and high-power supercapacitors to meet the demand for low-cost, long-term durability, and high safety. Nevertheless, the challenge caused by the finite ion adsorption/desorption capacity of carbon electrodes gravely limits their energy densities. This work describes titanium nitride@nitrogen-doped carbon nanocage (TiN@NCNC) composite cathodes for AZHSCs to achieve a greatly improved energy density, and the composites can be facilely synthesized based on the calcination of a mixture of tetrabutyl titanate and zeolitic imidazolate framework-8 in argon atmosphere. The resulting composites are featured by the ultra-fine TiN particles dispersed uniformly on the NCNC surfaces, enhancing the Zn2+ storage capabilities. Using TiN@NCNC cathodes, the AZHSCs can operate stably with a high energy density of 154 Wh kg−1 at a specific power of 270 W kg−1 and achieve a remarkable capacity retention of 88.9 % after 104 cycles at 5 A g−1. At an extreme specific power of 8.7 kW kg−1, the AZHSCs can retain an energy density of 97.2 Wh kg−1. With these results, we stress that the TiN@NCNC cathodes render high-performance AZHSCs and the facile one-pot method can easily be scaled up, which enables AZHSCs a new energy-storage component for managing intermitted renewable energy sources.

High-Performance Wearable Joule Heater Derived from Sea-Island Microfiber Nonwoven Fabric.

A three-dimensional (3D) hierarchical microfiber bundle-based scaffold integrated with silver nanowires (AgNWs) and porous polyurethane (PU) was designed for the Joule heater via a facile dip-coating method. The interconnected micrometer-sized voids and unique hierarchical structure benefit uniform AgNWs anchored and the formation of a high-efficiency 3D conductive network. As expected, this composite exhibits a superior electrical conductivity of 1586.4 S/m and the best electrothermal conversion performance of 118.6 °C at 2.0 V compared to reported wearable Joule heaters to date. Moreover, the durable microfiber bundle-PU network provides strong mechanical properties, allowing for the stable and durable electrothermal performance of such a composite to resist twisting, bending, abrasion, and washing. Application studies show that this kind of Joule heater is suitable for a wide range of applications, such as seat heating, a heating jacket, personal thermal management, etc.

Stereoselective and site-divergent synthesis of C-glycosides.

Carbohydrates play important roles in medicinal chemistry and biochemistry. However, their synthesis relies on specially designed glycosyl donors, which are often unstable and require multi-step synthesis. Furthermore, the catalytic and stereoselective installation of arylated quaternary stereocentres on sugar rings remains a formidable challenge. Here we report a facile and versatile method for the synthesis of diverse C-R (where R is an aryl, heteroaryl, alkenyl, alkynyl or alkyl) glycosides from readily available and bench-stable 1-deoxyglycosides. The reaction proceeds under mild conditions and exhibits high stereoselectivity across a broad range of glycosyl units. This protocol can be used to synthesize challenging 2-deoxyglycosides, unprotected glycosides, non-classical glycosides and deuterated glycosides. We further developed the catalyst-controlled site-divergent functionalization of carbohydrates for the synthesis of various unexplored carbohydrates containing arylated quaternary stereocentres that are inaccessible by existing methods. The synthetic utility of this strategy is further demonstrated in the synthesis of pharmaceutically relevant molecules and carbohydrates.

Construction of Cyclodextrin-Based Covalent Organic Frameworks for Efficient Encapsulation of Menthol.

The application of flavoring ingredients like menthol in the food industry is hindered by their high volatility and poor thermal stability, which lead to significant losses during processing and storage. Encapsulation of flavors into porous materials to obtain inclusion complexes (ICs) has proved to be an efficient strategy. In the present study, we synthesized a series of relatively food-safe three-dimensional anionic cyclodextrin-based covalent organic frameworks (CD-COFs) with spiroborate linkages using a facile microwave-assisted method. The high surface area and newly formed cavitied of COFs significantly enhanced the encapsulation efficiency of menthol compared to native CD materials. Our findings revealed that γ-CD-COF-Li, with Li+ as the counterion, achieved superior encapsulation efficiency of 25.9%, outperforming γ-CD-COF-Na, γ-CD-COF-K and α-CD-COF-Li under the same conditions. Thermal stability measurements show that the menthol/γ-CD-COF-Li-ICs effectively stabilize menthol against heat evaporation at elevated temperatures due to the strengthened interaction between menthol and γ-CD-COF-Li. The promising results of this research suggest that rapid advancements in COF technology will provide new opportunities for enhancing the stability of flavoring ingredients in the food industry.

Carbon Dots Employed for the Detection of Ranitidine and Elaborating the Detecting Mechanism.

Carbon dots (CDs) has been widely utilized in multiple fields, especially towards kinds of drug analyses, owing to its superior optical properties and satisfactory stability. Herein, we rapidly synthesized one kind of soluble bright-blue fluorescent CDs through a facile microwave method, while disodium ethylenediaminetetraacetic acid and phosphoric acid served as the raw materials. Importantly, introducing ranitidine into these CDs resulted in its decreased fluorescence, and thus an innovative method of detecting ranitidine was successfully established, which showed the favorable selectivity and anti-interference ability. With the optimal conditions, the standard curve diagram of F0/F against concentration of ranitidine was linear in the range of 6-2000 µM with a correlation coefficient of 0.9833, and the limit of detection (LOD) was calculated to be 4.2 µM. Meanwhile, we also explored the detecting mechanism of ranitidine by CDs, and elaborated that as the internal filtration effect. Consequently, we may broaden the avenues of detecting ranitidine on the basis of CDs.

Preparation of nanoporous poly (L-lactic acid) microspheres with controllable morphology via thermally-induced phase separation

This article describes a facile method to prepare nanoporous poly (l-lactic acid) microspheres via a thermally-induced phase separation method with controllable diameters. It was found that the morphology and diameter of PLLA microspheres were easily controlled by adjusting solvent ratio, quenching temperature, and PLLA concentrations. The results revealed that by using a ternary solvent system consisting of 1,3-dioxolane as a good solvent, 2-butanone as mid-solvent, and water as a poor solvent, the diameter of PLLA microspheres can be easily controlled by changing the ratio of 1,3-dioxolane and water. The diameter of PLLA microspheres prepared ranged from 28.8 ± 5.9 μm to 63.8 ± 12.5 μm. Moreover, the evolution of PLLA spherulitic structures grown from polymer solution was confirmed as well through varying solvent ratios and PLLA concentrations. The presence of water as a non-solvent governed the phase separation mechanism of the phase separation process. At the same time, the diameter of the spherulites is affected by the ratio of 1,3-dioxolane controlling the polymer crystallization process in the polymer-rich region. Interestingly, the surface of these spherulites contains nanopores due to the stacking of lamellar crystals of PLLA during polymer crystallization which contributed to its superhydrophobicity and superoleophilicity. Hence, the prepared PLLA spherulites were utilized as PLLA microspheres with nanoporous surfaces for the adsorption and removal of oil in oil/water and oil-in-water emulsion. This facile method provides a novel pathway to prepare nanoporous PLLA microspheres with controllable diameters for eco-friendly oil/water and oil-in-water separation applications.

Cu(I)-Induced 'Click Reaction' Involving Coordination and Covalent Assembly of Hybrid Borates for the Electrocatalytic CO2 Reduction.

The design and synthesis of hybrid borates by the organic ligand modification method are urgent and undeveloped areas of research. It is difficult to directly integrate organoboronic acids within inorganic borate chemistry by adopting the traditional preparation approaches. This work reports a facile synthetic method to synthesize a large family of pyrazole molecule-protected borates in a rapid and precise manner under mild conditions. A unique cyclic eight-membered B4O4-ring has been identified as the cluster core for all these hybrid borates with two different conformations (boat and crown). This strategy can be applied to a system of pyrazolyl molecules to generate such hybrid borates in two independent routes from organoboronic or inorganic boric acids. Furtherly, the mechanism of 'click reaction' between boric acid and pyrazole induced by copper ions has been proposed based on the synthetic conditions and the structure of intermediate. Due to the bimetallic Cu sites and the functional surfaces, these materials can be used as electrocatalysts for CO2 reduction reaction and efficiently enhance the selectivity of HCOOH and C2H4. Our strategy can be regarded as a typical template technique for organic molecule-protected borates.