Fluoride-ion (F-) batteries (FIBs) are a high-energy, cost-effective and safe alternative to lithium-ion batteries because of multiple-electron redox reactions, abundance of resources and absence of dendrite issues. Layered double hydroxides based on transition metals offer intriguing promise as F--storage electrodes but suffer from poor electrical conductivity. Herein, a new cathode material of FIBs was synthesized by in situ polymerization of pyrrole monomers on the surface of F- intercalated CoNi LDH (CoNi-F--LDH) platelets. Without destroying its 2D channel and anion storage capacity, the overall electrical conductivity of CoNi-F--LDH is improved. The resulting polypyrrole (PPy) coated CoNi-F -LDH exhibits a reversible capacity of similar to 60 mAh/g over 100 cycles at room-temperature, with a capacity retention of 86 %, superior to most of previously reported cathodes for FIBs. This work illustrates a potential pathway for updating LDH electrodes for room-temperature FIB chemistries.

MOOCs offer solutions to traditional constraints faced in chemistry experimental teaching,such as limited lab space,insufficient equipment,and rigid scheduling,However,challenges like underutilization,reluctance from students,and faculty unfamiliarity can undermine these efforts.To address these issues,the National Demonstration Center for Experimental Chemistry and Chemical Engineering Education(Beijing University of Chemical Technology)has explored how to effectively use MOOCs to enhance teaching quality.The team has established an extensive array of online experimental teaching resources,implemented a synergistic blended learning model,and developed both a faculty skill enhancement program and a comprehensive system for tracking and feedback on teaching quality.These initiatives have significantly improved educational effects.

At present,the undergraduate chemistry experimental teaching predominantly focuses on mononuclear complexes in the field of complex preparation experiments,often overlooking the significantly important polynuclear complexes within the complex family.Addressing this gap,we have designed a comprehensive chemical experiment involving a trinuclear iron(Ⅲ)complex,drawing from scientific research findings to enrich students'comprehension and application of complex chemistry.This design involved the preparation of an oxygen-bridged trinuclear iron(Ⅲ)complex,[Fe3O(CH3COO)6(H2O)3]NO3·4H2O,utilizing cost-effective and readily available iron(Ⅲ)nitrate nonahydrate and sodium acetate trihydrate as raw materials through water bath heating,cooling crystallization,and other steps.The iron content in the complex was determined by complexometric titration,and characterized by infrared spectroscopy,thermogravimetric analysis,powder X-ray diffraction,and electron paramagnetic resonance.The experimental is notable for its simplicity,efficiency,and eco-friendly approach.It incorporates ideological and political elements,and showcases the complex's novel and symmetrically aesthetic structure.During experimental teaching,students can also cultivate their appreciation of the intrinsic beauty of chemistry.The integration of science and education in this design helps to foster students'ability to analyze and solve problems,providing a feasible case for comprehensive chemistry experimental teaching for undergraduate students.

The long-acting sustained-release of active molecules is of great importance in chemical production, food preservative, drug delivery in vivo, and so on. However, the problems of initial-burst release and short release time (dominated by Fick's lows) commonly exist in sustained-release materials. Herein, we designed and fabricated two types of film materials to achieve slow, continuous, and long-term release of small molecules using methyl orange (MO) as a target release substance. B-MO@polymer films were obtained by embedding MO into polylactic acid/polyethylene glycol (PLA/PEG) substrate and then assembling a layered double hydroxide (LDH)/carboxymethyl chitosan (CMC) barrier layer on the substrate surface. Another type of film (LDH&MO@polymer) was prepared by blending LDH and MO into the PLA/PEG polymer matrix. These films show high loading capacities of similar to 500 mu g/cm(2) for MO and display long-acting sustained-release property arising from the barrier effect of LDH nano-brick. Specifically, for the B-MO@polymer film, the release time of 50% MO is 10 days and the release time of 80% MO can be extended to 30 days. Ultimately, the time for complete release (>96%) reaches over 60 days. By using LDH-embedded polymer as carriers for active molecules, the zero-order release of MO was realized for LDH&MO@polymer films, achieving sustained release within as long as 145 days. This work provides a new paradigm to achieve the long-acting sustained-release of active molecules through the barrier effect of 2D nano-bricks. Highlight Two types of films were obtained to achieve long-term release of small molecules. The films show high loading capacities for active molecules. The long-acting property is derived from the barrier effect of 2D nano-brick. The films can be produced in a large scale and have good application prospects.

The traditional experimental teaching mode of inorganic chemistry presents certain drawbacks.Advances in information technology offer new opportunities for reinvigorating the experimental teaching mode.This study explores the reform and practice of flipped classroom teaching mode within the context of inorganic chemistry experimental,specifically focusing on the preparation of inorganic crystalline compounds,utilizing the crystal structures as the starting point to engage interest,and employing the star questionnaires as an effective evaluation method.The practical process includes three stages:pre-class preparation,in-class exploration,and post-class feedback and reflection.Our findings reveal that the flipped classroom teaching mode effectively stimulates students'interest in inorganic chemistry experiment,and enhances their learning initiative,innovative consciousness,logical reasoning and problem-solving ability.

Surface and interfacial engineering of nanomaterials is essential for improving dispersion stability in liquids. In this study, we report that oleic acid (OA)- and stearic acid (SA)-functionalized layered double hydroxide (LDH) nanosheets as lubricant additives can achieve high dispersion and reduce friction and wear. LDH is a typical layered structure, and OA and SA are long-chain organic molecules that are not only compatible with base oils but also act as friction-reducing agents. The OA and SA molecules were branched onto ZnMgAl LDH nanosheets using dehydration condensation between the exposed OH groups on the surface of LDH and the COOH groups on the OA and SA molecules. Compared with that of the pristine ZnMgAl LDH, the dispersion of OA-ZnMgAl LDH and SA-ZnMgAl LDH was significantly improved. The surface-modified LDH exhibited superior tribological properties and great stability due to the synergistic lubrication effect between OA, SA, and LDH. Even at an ultralow concentration (0.15 wt %), the coefficient of friction and wear volume were reduced by ∼65 and ∼99%, respectively, compared to those of the base oil. Due to the green and simple synthesis method and excellent tribological properties, surface-functionalized LDH has enormous possibilities for future industrial applications.

The green synthesis and characterization experiment of a Zn(II) complex is a comprehensive experiment that combines the basic knowledge and the scientific research frontier of the complex.In this paper, a threedimensional complex was prepared using p-aminobenzenesulfonic acid (4-ABS) and ZnO as the main materials.The complex is characterized by single-crystal X-ray diffraction, infrared spectroscopy, thermogravimetry, UV absorption and fluorescence spectra.The configuration of the complex is optimized by the CASTEP module of Materials Studio (MS) software, which further supports the optimal structure and stabilization energy of the complex.The experimental process includes the complex preparation, evaporation concentration, decompression filtration, single crystal culture, UV absorption and fluorescence spectroscopy, thermogravimetric analysis, theoretical calculation, etc.The whole process is comprehensive and operable.Meanwhile, the experiment integrates green synthesis into the whole experimental scheme, establishing the concept of energy conservation and environmental protection.Through this experiment, students could not only understand the principles of coordination chemistry, but also learn the frontier of scientific research.Therefore, it is helpful to train the students' scientific thinking, and enhance their ability of innovation.

The combination of chemodynamic therapy (CDT) with photothermal therapy (PTT) is an efficacious strategy in cancer treatment to acquire satisfactory therapy efficiency in the endogenous redox reaction and external laser induction. In this work, we have designed Ce doped Cu-Al layered double hydroxide (CAC-LDH) ultrathin them through a bottom-up synthesis method, and further loaded them with indocyanine green (ICG). The synthesized ICG/CAC-LDH was used as a Fenton-catalyst and photothermal agent. With the Fenton activity, the ICG/CAC-LDH nanosheets could decompose H2O2 and exhibit a low KM value (1.57 mM) and an ultra-high Vmax (4.88 × 10-6 M s-1) value. Due to the presence of oxidized metal ions, ICG/CAC-LDH could induce intracellular GSH depletion and reduce Cu2+ and Ce4+ to Cu+ and Ce3+, respectively. The generated Cu+ and Ce3+ further reacted with local H2O2 to generate toxic hydroxyl radicals (˙OH) via the Fenton reaction. Owing to the obviously enhanced absorption of ICG/CAC-LDH at 808 nm, the photothermal efficiency of ICG/CAC-LDH increased significantly compared with ICG (ΔT = 34.7 °C vs. 28.3 °C). In vitro studies substantiate the remarkable CDT/PTT efficacy, with complete apoptosis of HepG2 cancer cells (the cell viability is less than 2%) treated with 25 μg mL-1 of ICG/CAC-LDH. Furthermore, ICG/CAC-LDH could also act as a contrast agent for cancer magnetic resonance imaging (MRI) and photoacoustic imaging (PAI). These results demonstrate the potential of ICG/CAC-LDH as an integrated agent for dual-modal imaging and synergistic CDT/PTT.

The identification of relevant impurities in the precursor chloroephedrine of the illegal drug methamphetamine will help for regulating this illegal drug and finding its sources. An efficient and effective method for qualitatively analysing samples of the drug was developed using high-performance liquid chromatography-hybrid ion trap/time-of-flight mass spectrometry (HPLC-IT/TOF MS). The chloroephedrine fragmentation pathway was proposed using HPLC-MSn. Two impurities (1R, 2S)-beta-chloro-methamphetamine and N-(1-phenyl-allyl)-beta-chloro-methamphetamine in chloroephedrine samples were identified by the optimized HPLC-IT/TOF-MS. The synthetic route of the chloroephedrine samples was proposed by the analysis of these impurities. The established method would make it easy to identify impurities and find the source of this illegal drug. In addition, a method for the preparation of a chloroephedrine reference standard from actual samples was developed using preparative HPLC. The purity of the obtained standards was 99.51%.

The tumor microenvironment (TME), which is characterised by high H2O2 and glutathione (GSH) levels, low pH value and hypoxia, imposes crucial influences on tumor therapeutic outcomes. Rational design and preparation of nanomaterial systems that are responsive to the intrinsic properties of the TME open a promising avenue towards tumor-specific treatment. Herein, CoMn-layered double hydroxide (CoMn-LDH) nanosheets were synthesized via a bottom-up method followed by surface modification with a photosensitizer, chlorin e6 (Ce6), which exhibited TME-responsive imaging as well as photodynamic and chemodynamic synergistic therapy (PDT/CDT). Due to their ultralow bond energy and large adsorption energy, CoMn-LDH nanosheets show fast self-degradability in a GSH (10 mM) microenvironment, giving an excellent CDT activity in mildly acidic conditions (pH = 6.5), superior GSH removal ability (99.82%) and O2 production (35.37 μg L-1 s-1). Moreover, Ce6/CoMn-LDH nanosheets display satisfactory photoacoustic (PA) imaging and GSH-enhanced magnetic resonance imaging (MRI) with a 45.1-fold T1-enhancement. In addition, both in vitro and in vivo therapeutic tests based on Ce6/CoMn-LDH demonstrate a satisfactory anticancer activity with complete cancer cell apoptosis and dramatic tumor elimination. This work provides a new perspective for the design of multifunctional 2D nanosheets towards a fully promoted TME-responsive synergistic therapy, which holds great promise for future clinical diagnosis and treatment.

中外合作办学是中国高等教育的重要形式之一。根据北京化工大学中外合作办学的情况,以无机及分析化学实验的教学内容为切入点,总结了教学过程中存在的问题,主要表现为学生的逻辑思维能力、基础理论联系实践及数据处理能力等方面存在诸多不足。为解决这些问题,培养具备国际化能力的创新人才,作者从培养学生科学的逻辑思维能力、理论与实验相结合并融思政教育于课堂、应用软件在实验数据处理中的应用等方面进行了教学手段与方法的创新与探索,为国际教育学院生物工程班学生将来能够顺利与国外后续课程的成功对接打下坚实的基础。

Development of the fluorescent and stability-enhanced scheme for silver nanoclusters is challengeable. In the present study, silver nanoclusters stabilized by nuclear fast red sodium salt (NFR) were assembled with Mg2Al-layered double hydroxide (LDH) nanosheets. The as-prepared films (AgNCs-NFR/LDH UTFs) were confirmed by powder X-ray diffraction (XRD), UV vis, fluorescence spectra,atomic force microscope (AFM) and scanning electron microscope (SEM). Owing to the confined effects of 2D layered LDH nanosheets, the fluorescence intensity and photostability of AgNCs-NFR/LDH UTFs have improved significantly in comparing with that of AgNCs-NFR solution. By introducing Cu2+ ions as a modulator, AgNCs-NFR/LDH UTFs were applied successfully to determination guanine in the concentration range of 10-20 mu M and 20-100 mu M. The limit of detection was 1.85 mu M guanine. Moreover, the selectivity for guanine over the other nucleotide bases (such as adenine, thy mine, cytosine and uracil) and some potential interfering substances were investigated. The constructed sensor films were simple and economic which avoided a sophisticated synthetic process, and the detected reactions completed within 5 min. Therefore, this paper provides a new opportunity for fabrication the nanocomposite sensor based on AgNCs-NFR/LDH for guanine sensing.

Fluorescent copper nanoclusters (CuNCs) have been drawing great research interest because of their fascinating physicochemical properties. However, the low quantum yield (QY) and poor stability of CuNCs have limited their applications. In this work, CuNCs were anchored onto the layered double hydroxides (LDHs) by the layer-by-layer (LBL) assembly method, and the obtained CuNCs/LDHs ultrathin films displayed an ordered periodic long-range structure and uniform morphology, The CuNCs/LDHs films indicate the strong orange-red emission with higher QY (16.66%) and prolonged fluorescence lifetime (9.05 mu s), which is obviously better than that of individual CuNCs. The experimental studies and theoretical calculations both reveal that the location and confinement effects derived from LDHs nanosheets enhance the QY of CuNCs. In addition, the CuNCs/LDHs films are temperature-responsive in photoluminescence (PL) and electrogenerated chemiluminescence (ECL). Consequently, it provides a new and facile approach to fabricate CuNCs-based films accompanied by excellent luminescent properties, which indicate the great potential for temperature sensing applications.

A method for the identification of relevant impurities in illegal o-chlorophenyl cyclopentyl ketone drug was developed. Identification of impurities could help regulation of this illegal drug and allow the sources of samples of the drug to be identified. An efficient and effective method for qualitatively analyzing samples using high performance liquid chromatography-hybrid ion trap/time-of-flight mass spectrometry (HPLC-IT/TOF MS) was developed. The o-chlorophenyl cyclopentyl ketone fragmentation pathway during HPLC-MSn was determined by analyzing a standard by HPLC-IT/TOF MS. The optimized HPLC-IT/TOF MS method allowed two impurities in o-chlorophenyl cyclopentyl ketone samples to be identified. According to the exact mass data of MSn and the element composition analysis, two impurities were identified as o-chlorobenzoic acid anhydride and 1,2-di-o-chlorobenzoylcyclopentene. The synthetic route of the o-chlorophenyl cyclopentyl ketone samples was proposed by analysis of these impurities. The established method made it easy to identify impurities and find the source of this illegal drug. A method for the preparation an o-chlorophenyl cyclopentyl ketone reference standard from actual samples using preparative HPLC was also developed. The mobile phase was methanol-water (85:15, v/v) and flow rate was 8 mL/min. The purity of the obtained standards, determined by analytical HPLC, was 99.53%. This method is simple, efficient, and can be used for the preparation of other illegal drugs.

The interaction of alizarin with aminophenylboronic acid (ARS-PBA) was used through a new strategy for electrochemical sensors of glucose. In the present work, ARS-PBA complex and the layered double hydroxide nanosheets (LDH nanosheets) were successfully assembled on indium tin oxide (ITO) electrodes via layer by layer technology method. The resulted electrode was characterized by UV-vis, X-ray diffraction (XRD), atomic force microscope (AFM) and scanning electron microscope (SEM) to achieve the morphological, structural and compositional information. Cyclic voltammetry and differential pulse voltammetry were conducted to investigate electrochemical properties of the modified electrode. Moreover, the modified electrode was used as a non-enzymatic sensor for glucose determination, exhibiting good electrochemical properties, fast response time and long-term stability. At the optimum conditions, the constructed electrode sensor shows a linear range of 0 - 1.00 mu mol/L and a low detection limit of 4.0 nmol/L (S/N = 3) for glucose. On the basis of affinity between glucose and ARS-PBA complex, the functionalized electrode showed a high selectivity toward glucose over other concomitant biomolecues (dopamine, uric acid and ascorbic acid). Therefore, a simple and effective electrochemical method was developed and offers a complementary tool for the detection of glucose.

A dual-stimuli responsive strategy is developed for the detection of melamine and temperature. Flavin mononucleotide (FMN) was immobilized onto layered double hydroxide (LDH) nanosheets through a layer-by-layer process. The as-prepared composite films show higher emission intensity, prolonged fluorescence lifetimes and fluorescence responses towards melamine and temperature.

It is of great significance to sense cysteine (Cys) in a simple and fast way because of its potential applications in biological processes.

In this study, new facile, economical and fluorescent ultrathin films (UTFs) for detection of tiopronin are developed. The UTFs have been fabricated by combining the alizarin red S-boric acid adduct (ARS-H3BO3) with MgAl layered double hydroxide (LDH) nanoparticles through the layer-by-layer (LBL) assembly technique. UV-vis, fluorescence spectroscopy, XRD, SEM and AFM have been adopted to monitor the assembly process. The UTFs display a uniform morphology and a periodic layered structure. Using ARS as a probe, which does not emit fluorescence by itself but displays fluorescence when complexed with boron, the assembled ARS-H3BO3/LDH UTFs display a high luminescence response to tiopronin. In the presence of Cu2+, the fluorescence of UTFs was quenched, which is attributed to the complexation between Cu2+ and ARS. Upon adding tiopronin to the UTF-Cu system, tiopronin would form a complex with Cu2+ preferentially, leading to the increased fluorescence of UTFs. Based on the above mechanism, a turn-on fluorescent ensemble for tiopronin is developed. A linear response was obtained in the range of 0-80 ng mL(-1), with a detection limit of 0.47 ng mL(-1). Compared with ARS and other analytes, the tighter binding of tiopronin to Cu2+ led to an assay with high specificity. Therefore, this work provides a facile LBL strategy for the fabrication of a solid state sensor based on ARS dye for detection of tiopronin.

A fluorescent ultrathin film (CTA-AgNCs/LDH) is developed for the determination of melamine with high selectivity, low detection and practical utility.

The ultrathin films (UTFs) based on erythrosine B/layered double hydroxide have been prepared by a layer-by-layer assembly technique. UV–vis, fluorescence spectroscopy, XRD, SEM and AFM have been adopted to monitor the assembly process. The UTFs display a uniform morphology and a periodical layered structure. Fluorescence spectra demonstrated that the (ER/LDH)26 UTF exhibited the optimal luminescent intensity. Moreover, the fluorescence-response of (ER/LDH)26 UTF to bovine serum albumin (BSA) was investigated. The films have a good selectivity and reusable ability. The specific fluorescence response of the UTF is attributed to a strong interaction between ER and BSA. Circular dichroism (CD) revealed that the secondary conformation of BSA has been changed from α-helical structure to β-sheet after adsorbed on (ER/LDH)26 UTF, further confirmed the interaction between BSA and ER/LDH film. These results demonstrate that ER/LDH system can serve as a good candidate for the solid-sate luminescence and sensor materials for BSA.