Lignin is one of the most abundant and significant natural polymeric materials in the world， and its position is only second to cellulose. In woody plants， lignin content accounts for about 25%. Due to its chemical inertness and structural complexity， the application of lignin is very limited. Therefore， the chemical modification of lignin is the key method to transform lignin into functional materials， which is of great significance for the sustainable development of resources and environment. In this review， the research progress on the development of chemical modification of lignin and its applications， including wastewater treatment， heterogeneous catalysis and other aspects， are summarized. Furthermore， discussions on challenges and perspectives in the field of lignin modification are also presented.

Water electrolysis is one of the most efficient and environmentally benign methods for the hydrogen production using renewable but intermittent power sources. Proton exchange membrane （PEM） water electrolyzers hold great significance for renewable energy storage and conversion. The acidic oxygen evolution reaction （OER） is one of the main roadblocks that hinder the practical application of PEM water electrolyzers. Highly active， cost-effective， and durable electrocatalysts are indispensable for lowering the high kinetic barrier of OER to achieve boosted reaction kinetics. To date， a wide spectrum of advanced electrocatalysts has been designed and synthesized for enhanced acidic OER performance， though Ir and Ru based nanostructures still represent the state-of-the-art catalysts. In this Progress Report， recent research progress on novel electrocatalysts with acidic OER performance is reviewed. First， the basic understanding of acidic OER， including the reaction mechanism， is discussed. On this basis， the design and synthesis progress of noble metal acidic OER electrocatalysts are reviewed for noble metal Ir， Ru single atoms， alloys， oxides， etc. Finally， the future development of acidic OER is prospected from the aspects of reaction mechanism research and more efficient electrocatalyst design.

The effect of hydroxyapatite （HA） samples in different quality states on X-ray diffraction （XRD） results has been investigated systematically. The effects of sample state （block， layered and powder， etc.）， experimental method selection （powder polycrystalline diffraction and thin film grazing incidence diffraction， etc.） and detection environmental conditions （temperature， humidity and X-ray irradiation） on XRD detection are investigated. The results show that， compared with the block sample of HA， the intensity of the characteristic XRD peak of the powder sample after grinding and sieving treatment is significantly enhanced. For HA multi-layered growth samples， the phase analysis of each layer can be accurately achieved by combining grazing incidence and conventional powder diffraction. The particle size， amount， and filling method of the HA powder sample can also affect the XRD detection. The results show that the characteristic peak intensity of the HA powder sample with a particle size of 37 μm is about twice that of the sample with a particle size of 137 μm. In addition， the vacant sample preparation in the middle of a small amount of samples can cause the peak position of the characteristic peak to shift from 31.8 to 31.4（°）， and the peak intensity decreases from 11213.68 to 601.65. Moreover， appropriate storage and detection methods can prevent and avoid erroneous detection and result analysis for samples with poor stability to ambient temperature and humidity. Thus， ensuring high-quality XRD detection data and ensuring experimental data quality requires comprehensive quality control.

Electrochemical synthesis of hydrogen peroxide （H₂O₂） via two-electron oxygen reduction reaction （2e-ORR） is featured with cost effectiveness and environmental friendliness， and enables on-site production of H₂O₂ on demand. One of the key technologies is the development of safe， economical and efficient 2e-ORR catalysts. Here， the research progress in precious-metal-based catalytic materials for the synthesis of H₂O₂via 2e-ORR in recent ten years is reviewed. This review starts with the fundamental mechanism of ORR， pointing out the tuning knobs of reaction pathway on precious-metal surfaces， namely， ^*OOH binding energy and O₂ adsorption mode. The regulating methodologies of geometric structure and electronic structure of precious-metal materials are summarized and exemplified， emphasizing the importance of balanced optimization of catalytic activity and selectivity. We have also briefly introduced the lab-scale methods for performance evaluation of 2e-ORR catalysts. Finally， the challenges and prospects of H₂O₂ synthesis catalyzed by precious metals are discussed， especially the catalyst stability and the objective evaluation of cost. This review is expected to provide a reference for rational design of novel 2e-ORR catalysts.

Portulaca oleracea L. （PO） contains various active chemicals. PO is a medicine and food homologous to traditional Chinese medicine， which has high medicinal and edible value. In recent years， it has been widely used in the field of the chemical industry， especially in the field of cosmetics. Cosmetic companies have developed facial masks， essence， skin care water， cleanser and other cosmetic products that have been added the active ingredient extracted from PO. However， the related commercial cosmetics of PO mainly contain the ethanol extracts， while there are few cosmetic products involving its aqueous extracts， such as polysaccharide and polyphenol. The emergence of new dosage forms has enriched the research on the percutaneous delivery system of PO in cosmetics， and new carriers such as liposomes， delivery bodies， and β-cyclodextrins can be developed in the future. The chemical composition， function， mechanism， and application of Portulaca oleracea in cosmetics are summarized， and some suggestions and prospects are put forward on the development and application of Portulaca oleracea in cosmetics.

V-based solid solution hydrogen storage alloys possess BCC structures and have the weight hydrogen storage capacity of above 3.8% and the charge/discharge capacity of 1052 mA·h/g， which is superior to series alloys such as AB₂ type and AB₅ type. They exhibit high hydrogen solubility and diffusion coefficients at ambient temperature and pressure， therefore， and have a broad application prospect in the field of hydrogen storage and transport system as well as hydrogen energy supply. However， V-based solid solution alloys suffer from difficult activation， harsh hydrogen release conditions， short cycle life and oxygen sensitivity and oxidation. Studies have shown that rare earths have a positive effect on modifying various solid-state hydrogen storage materials. The inclusion of rare earth elements in V-based solid solution alloys through elemental substitution or doping produces a vigorously active second phase of rare earths or rare earth oxides， substantially enhancing the material's capacity for hydrogen absorption and desorption， cycling durability， and anti-toxicity characteristics. Simultaneously， it decreases the oxygen content and enhances the activity properties of materials. In terms of electrochemical performance， the addition of rare earth elements can significantly improve the cycle stability， corrosion resistance and high rate discharge performance of the alloy electrode. Therefore， rare earth element substitution is a well-established method for achieving practical applications of V-based solid solution hydrogen storage materials. This report presents the recent research status of rare earth-modified V-based solid solution hydrogen storage alloys， with a focus on summarizing the rare earth elements' mechanism of action and providing an outlook for future key research directions.

Among many hydrogen production technologies， electrolysis of water has many obvious advantages， such as environmentally friendly， simple and easy to operate. Industrial-scale hydrogen production is typically carried out at high current density. A great number of H₂ bubbles will generate on the electrode surface during the process of hydrogen production. The aggregation and adhesion of bubbles on the electrode surface will lead to a large number of active sites being covered， resulting in the reduction of the efficiency. Therefore， regulating bubble wetting behavior is crucial for industrial electrolysis of water. In recent years， superaerophobic materials have attracted much attention due to their unique wetting capabilities. Superwetting interface materials can be constructed by controlling the chemical composition of the electrode surface and constructing rough structure at micro and nano scales. This type of material has a superhydrophilic/superaerophobic interface structure， which facilitates the effective infiltration of aqueous electrolyte and accelerates the release of in-situ generated bubbles， thus enhancing the water splitting performance of the catalyst. This paper systematically introduces the water splitting catalysts with superhydrophilic/superaerophobic interfacial structures reported in recent years， outlines the synthetic design strategies and catalytic performance of the catalysts， and the current research status， challenges and application prospects of superwetting water splitting catalysts are summarized and prospected.

Metal-organic frameworks （MOFs） materials have gained a lot of attention because of their good stability， excellent adsorption properties and designability. In the last decade， the research about MOFs materials has developed rapidly. As an important research tool， theoretical computation and simulation have played an irreplaceable role in the study of adsorption mechanism and high-throughput screening of MOFs materials and other work studies. This work summarizes the computation and simulation methods including quantum mechanical calculations， molecular mechanics simulation， mesoscopic simulation， finite element simulation and machine learning， summarizes the different levels of computation and simulation methods used to solve the main scientific problems in the research of MOFs materials， and highlights the progress of the application of these methods in several typical research areas， such as the adsorption separation and storage of gases， adsorption separation and extraction of organic compounds in solution， catalytic reaction and drug loading. Finally， the prospect and development of computation and simulation for the study of MOFs materials are proposed.

Urea as an effective hydrogen carrier can be used in urea electrolysis （UE） for hydrogen production and direct urea fuel cells （DUFC）. In urea electrolysis， the coupling of urea oxidation reaction （UOR） at the anode and hydrogen evolution reaction （HER） at the cathode to produce hydrogen is more cost-effective than water electrolysis， with energy consumption reduced by about 30% and economic cost reduced by about 36%. In the direct urea fuel cells， urea as fuel at the anode and coupled with oxygen reduction at the cathode can convert chemical energy directly into electrical energy. As the basis of these two energy conversion technologies， UOR has received more and more attention. This review discusses the reaction principle and performance description parameters of UOR in alkaline electrolytes and introduces the application of UOR in UE and DUFC. Attention is also given to the principles of UE and DUFC and the development status of some catalysts， and finally， the challenges faced in the development of UE and DUFC are also commented. Hopefully， this review will be helpful for understanding the basics of UE and DUFC.

Gunpowder is one of the four great inventions of ancient China， which once had an important impact on the world pattern and development process. However， after the late Ming Dynasty and the early Qing Dynasty， gunpowder firearms gradually declined in China. Gunpowder moved to the West with the war and became black powder， which promoted the birth and development of modern chemical science. The development of chemical science is of great significance to the dynamite family. The brilliant achievements of China's modern king of dynamite revitalize the glory of Chinese gunpowder. This paper reviews the legendary development course and the groundbreaking role of dynamite， describes the properties， rich types and unique working principles of its special chemical energy， and tries to trace the internal mechanism of gunpowder combustion and explosion. It aims to highlight the importance of scientific thinking mode and the development of chemistry discipline to the study of explosives， so as to continuously enrich the knowledge connotation of chemistry students， stimulate their enthusiasm for innovative thinking， enhance their professional confidence， cultural confidence and national confidence， and promote the spirit of scientists.

A polyethylene glycol （PEG） derivative PBA-PEG-SA， which connects phenylboronic acid （PBA） with an amide bond at one end and stearic acid （SA） with an ester bond at the other end， is synthesized by substitution reaction and esterification reaction. And a liposome with pH response characteristics is prepared by co-assembly of PBA-PEG-SA with distearyl choline phosphate （DSCP） and cholesterol （CH）. When PBA-PEG-SA， cholesterol and DSCP are assembled at a mass ratio of 1∶3∶10， the particle size of the prepared liposome is 115 nm， and it could maintain good particle size stability within 20 d. In addition， the liposome has good biocompatibility. When the concentration reaches 800 μg/mL， the survival rate of mouse embryonic fibroblast （NIH-3T3）and hepatoma cell （HepG2） can reach more than 90%. At the same time， after loading doxorubicin （Dox）， compared with DSCP liposomes （Lip/Dox）， Fru/PBA/Lip/Dox liposomes modified with PBA and coated with Fru can effectively enhance the cytotoxicity of HepG2， reduce the toxicity to normal cells NIH-3T3， and improve the endocytosis of cells to drug-loaded liposomes due to the selective binding of phenylboronic acid and fructose. Therefore， the liposomes co-assembled by DSCP and PBA-PEG-SA have good pH response performance and enhance the enrichment ability of liposomes in tumor tissue， which will have good application prospects in the field of tumor therapy.

Solid oxide fuel cells （SOFCs） are energy conversion devices with high conversion efficiency， environmental friendliness， and wide fuel adaptability. As the place of electrochemical reactions， electrodes play a key role in the performance of SOFCs. Compared with the conventional electrode materials， the electrode with nanoparticles exsolved on the surface show stronger catalytic activity and excellent electrochemical performance. In this article， the investigations of in situ exsolution of perovskite-type electrode materials are summarized. Firstly， the effect of the crystal structure of perovskite on exsolution of electrode is discussed. Secondly， the influences of defects in perovskite on the exsolution of nanoparticles are introduced in detail. And then two main methods for in situ exsolution are compared and different exsolved products are analyzed. Finally， the difficulties and challenges faced to the in situ exsolution investigation for the SOFC electrode are put forward on the basis of the existing research， which points out the direction for future study.

Glyphosate， also known as N-（methyl phosphate）-glycine， is an organophosphorus pesticide with appreciable herbicidal activity. During its production process， a waste stream composed of complex components （glyphosate wastewater） is produced with the feature of abundant organic matter and high salinity， which obstructs the harmless treatment and resource utilization of glyphosate wastewater. In this paper， the principle and performance of several methods to treat glyphosate wastewater， such as incineration， advanced oxidation， adsorption， chemical precipitation， and membrane separation technology， are introduced， and their advantages and disadvantages are summarized. Incineration， advanced oxidation technology and biochemical treatment of glyphosate wastewater have low selectivity， which is not conducive to the resource utilization of glyphosate wastewater. In view of limited capacity of adsorption， developing the adsorbents possessing large adsorption capacity is urgently needed for the adsorption method in the industrial application of glyphosate waste treatment. chemical precipitation method exhibits excellent separation performance for the phosphate components even in the severe environment of high salt and high COD， whereas it produces a considerable amount of sludge with complex composition. Membrane separation method has been extensively applied to remove impurities in the waste stream and effectively recover valuable compositions， whereas the mere use of membrane technology could not meet the treatment demand due to the complexity of glyphosate wastewater. In this regard， new types of membrane technologies， such as liquid membrane separation and polymer inclusion membrane technology， have been developed. In terms of a variety of advantages including appreciable stability， longlifespan， easy operation and small footprint， the newly developed membrane separation technologies exhibit their prospectsingreen and economic treatment oforganic wastewater containing high salt and recycling of valuable composition.

Traditional industrial nitrogen fixation （NF） process uses the Haber-Bosch process which requires high temperature and high pressure， causing high energy consumption and serious pollution. Gliding arc plasma （GAP） combines the advantages of thermal plasma and cold plasma， which can efficiently produce active species and improve energy efficiency obviously. It has great application potential in the field of NF， and has received extensive attention in recent years. However， the research on NF via GAP is relatively fragmented at present. It is necessary to summarize the specific content. The research progress of NF via GAP at home and abroad in past 10 years is reviewed in this paper， mainly including GAP discharge mechanism， reactor design， process parameters and NF reaction mechanism. GAP discharge has B-G mode with breakdown following gliding discharge and A-G mode with continuous steady discharge. A-G mode discharge helps to improve nitrogen fixation efficiency. With the continuous development of GAP discharge technology， the electrode structure in GAP reactor has evolved from the traditional 2D blade structure to a variety of 3D cylindrical structures. Based on process optimization， GAP facilitates the vibrational excitation of N₂ molecules， thereby promoting the splitting and transformation of N₂ molecules. In the last， the research on NF through GAP is prospected.

Transition metal phosphate has attracted the attention of researchers in the field of electrolytic water because of its advantages of safety， cleanliness， low cost and high efficiency. Phosphate groups in phosphate have unique atomic geometric structure， strong coordination and various orientations， which are beneficial to stabilize the middle valence state of transition metals and accelerate proton conduction rate. However， its poor conductivity and low porosity have prompted researchers to explore and design more efficient transition metal phosphate electrocatalysts. Although researchers have invested a lot of time and energy， there are still many problems to be solved in the efficient development and utilization of transition metal phosphate electrocatalysts. In this paper， combined with the latest research progress of transition metal phosphate electrocatalysts， the development and design strategies of phosphate by researchers in recent years are introduced from the aspects of morphology control， defect engineering and interface engineering. At the same time， the opportunities and challenges faced by this kind of catalyst in the future material field are discussed from the aspects of scientific research and practical application.

Silicon （Si） has become the most promising anode material for the next generation lithium-ion battery because of its ultra-high theoretical specific capacity. However， the intercalation and removal of lithium-ions will cause a great change in the volume of silicon microparticles（SiMP）， which will lead to the pulverization of SiMP and irreversible attenuation of electrode capacity， which seriously limits the wide application of silicon-based materials. A large number of reports in the past have shown that polymer binder can effectively overcome the “island effect” caused by the volume expansion of SiMP. It could maintain the integrity of the electrode in the charge-discharge process， and then improve the electrochemical performance of the electrode. According to the structure classification of polymer binders， they can be roughly divided into four categories， linear， branched， cross-linked and conjugated. When the binders with different molecular structures are used as silicon-based negative electrode， the electrodes show different electrochemical properties. Particularly， when polymer binders with multiple molecular structures are designed， the practical application of silicon-based negative electrodes will be greatly promoted. By analyzing the effects of various polymer binders on the electrochemical properties of silicon anode， the differences of binders with different molecular structures can be clearly obtained， and then provide ideas for the development of silicon anode polymer binder in the future. Finally， this paper proposes the design direction of the next-generation polymer binder to promote its development towards large-scale application and industrial production.

Hydrogen （H₂）， a renewable green energy source， has been widely focused on tackling environmental issues and fossil energy shortages. The development of low-cost， highly efficient and stable electrocatalysts towards hydrogen evolution reaction （HER） is one of the major challenges facing the large-scale utilization of hydrogen. Cobalt phosphide （CoP） has been widely studied in the field of electrocatalytic HER due to its metal-like properties and corrosion resistance in acid and alkali electrolytes. This review firstly elaborates the major advantages and challenges for CoP heterojunction as electrocatalyst for HER. Next， the different effects of the CoP heterojunction on HER are discussed. Finally， the prospects of CoP heterojunction for HER electrocatalysis are summarized and prospected.

AB₂ hydrogen storage alloy has attracted extensive research interest due to its advantages of high theoretical hydrogen storage capacity， long cycle life and high cost performance. However， AB₂ hydrogen storage alloy has some disadvantages such as activation difficulty， toxicity and high platform， which hinders its practical application. In recent years， aiming at the defects of AB₂ alloy， researchers have carried out a lot of modification studies and made great progress. This paper summarizes the research progress of AB₂-type hydrogen storage alloys in the past 30 years， focuses on the methods to improve its hydrogen storage performance， and puts forward the key research directions of AB₂-type alloys in the future.

Special asphalt has the characteristics of high added value， specificity of application scenarios and great difficulty in development. The research progress of special asphalt including modified asphalt， impregnating asphalt， coated asphalt， mesophase asphalt and other types of asphalt is reviewed. Researchers should strengthen the application of characterization methods to further clarify the multi-scale variation rules of atoms， molecules and compounds in the production process of asphalt products， so as to regulate the key technological conditions in the development and production process. According to the characteristics of different raw materials， it is suggested to adopt suitable processing technology to produce different kinds of special asphalt， so as to realize the fine and high value-added utilization of asphalt resources.

MXenes is a hydrophilic two-dimensional inorganic materialand has a wide range of dispersion properties and application characteristics through the regulation of its morphology and surface end-group. The etching method and dispersibility in organic solvents are studied. It is found that Al as the “A” layer of the MAX phase is more likely to be etched to form Ti₃C₂T _x . Multilayer Ti₃C₂T _x can be obtainedby HF etching. Etching of MAX by in situ generated HF from HCl+LiFis more likely to obtain single layer Ti₃C₂T _x solution. DMF and other organic solvents as dispersants can change Ti₃C₂T _x from hydrophilic to hydrophobic， and Ti₃C₂T _x can effectively dispersed in lubricating oil as the dispersant aid. Ti₃C₂T _x modified with dodecyl phosphate shows a better hydrophobicity with the water contact angle of higher than 90（°）， which can be used to prepare higher concentration Ti₃C₂T _x -lubricating oil dispersion. This research provides a broad idea and a solid foundation for the application of MXenes in organic dispersion and lubricant additives.

Biomass-derived hard carbon has advantages of abundant raw-material resources， sustainability， low cost， and high sodium storage capacity， making it an ideal anode material for sodium-ion batteries （SIBs）. The microstructure of biomass-derived hard carbon materials is one of the key factors to influence the sodium-ion storage performance. This review summarizes the research status on the mechanism of biomass-derived hard carbon anodes for sodium-ion storage. Preparation methods for the high-performance biomass-derived hard carbon anodes were summarized from the point of views of biomass sources. The relationship between structural regulation and the sodium-ion storage enhancement was discussed. Last but not the least， future research directions were prospected for developing high-performance biomass-derived hard carbon anodes for SIBs.

Metal-organic frameworks （MOFs） material， as a new multifunctional material， has attracted more and more attention in the field of water treatment of catalytic activation in advanced oxidation technology， due to its high surface area， adjustable pore structure， excellent thermal and chemical stability. This paper focuses on the research progress of activating persulfate by MOFs-based catalyst in the field of water treatment in recent five years. In this paper， various MOFs-based catalyst and their common synthesis methods in persulfate activation are introduced. Then， the oxidation mechanisms of MOFs-based catalyst during the activation of persulfate are summarized； the common modification methods of MOFs-based catalyst are introduced. Finally， some suggestions for the future research direction of activated persulfate by MOFs-based catalyst are put forward. This review will help to deepen the understanding of MOFs-based catalyst activating persulfate to degrade organic pollutants， and provide theoretical reference for the development of new heterogeneous MOFs-based catalysts based on PS activation.

Malignant tumors are major diseases that threaten human health. The development of safe and efficient antitumor drugs and their delivery systems is an important guarantee for improving the efficacy of antitumor drugs. In recent years， cyclodextrin-based antitumor drug host-guest delivery systems have received much attention. Cyclodextrins are cyclic oligosaccharides obtained by amylolytic enzymes with an external hydrophilic internal hydrophobic structure， and have been widely used in gene therapy， immune cell therapy， immune-targeted therapy， and chemotherapy. This review summarizes the advances related to cyclodextrins as antitumor drug delivery carriers， and also provides a perspective and discussion on the opportunities and challenges of host-guest delivery systems in oncology therapy.

With the increasing demand for green and efficient energy storage devices， advanced technologies for clean energy conversion have attracted close attention from researchers. Fuel cells with environmental friendliness and high energy conversion efficiency are promising alternatives to traditional energy sources. However， Pt catalysts with high commercialization degrees in the industrial catalysis field have some problems， such as high cost， poor stability and weak anti-toxicity ability， which limits the further development of fuel cells. The development of non-Pt oxygen reduction reaction （ORR） catalysts with abundant reserves， low cost and excellent performance is an effective way to improve the efficiency of fuel cells. In this paper， based on the research results at home and abroad in recent years， various types of non-Pt system ORR catalysts， including non-precious metal and non-metal catalysts， are systematically introduced. The advantages， disadvantages and modification strategies of various catalysts are summarized， and challenges and prospects for the development of ORR electrocatalysts are put forward.

Raman spectroscopy is a non-destructive analytical technique that provides detailed information on the chemical structure and molecular interactions of a sample. Insitu spectroelectrochemistry combined by spectroscopy and conventional electrochemical methods is a powerful technique for dynamically detecting the structure and phase composition of electrode materials. It has broad application prospects in energy storage and provides information on the micro-structure at the electrode interface. Raman spectroscopy can effectively characterize the change of various cathodic materials and complex ions in aluminum chloride-based electrolytes of rechargeable aluminum-ion batteries （AIBs） during the charging and discharging processes in situ. Combined with characterization techniques， such as XRD and XPS， Raman spectroscopy can effectively reveal the energy storage mechanism of rechargeable aluminum-ion batteries， including the study of electrolytes and electrode materials and insitu monitoring of electrode surface reactions. The study of the nature of electrode materials and interface structures can guide the optimal design of battery materials and microstructures， and the in-situ exploring of electrode surface reactions can help to conduct an in-depth study of the mechanism of electrode interface reactions for guiding the structural optimization of cathode materials and promoting the development of rechargeable aluminum-ion batteries.

Sulfuric acid， nitric acid， phosphoric acid and perchloric acid are usually used as catalysts for the preparation of organic peroxides. Due to the corrosion of strong acid to the equipment， the catalyst can not be reused， the amount of waste water after treatment is large， and the post-treatment cost is very high. The preparation of organic peroxides with heterogeneous catalysts has been paid more and more attention. Heterogeneous catalysts have the advantages of high activity， good stability and reusability， simple post-treatment， less equipment corrosion， and less environmental pollution. In this paper， on the basis of a brief introduction of the homogeneous preparation process of organic peroxides， the heterogeneous catalysts for the preparation of organic peroxides， including ion exchange resins， molecular sieves， phase transfer catalysts， metal oxides， polymer carrier catalysts and carbon-based support catalysts are summarized. The reactors and preparation processes are discussed， and the development direction of heterogeneous catalytic synthesis of organic peroxides is described. The study has strong reference value and guiding significance for understanding the progress in the preparation of organic compounds by heterogeneous catalysis， developing heterogeneous catalysts with excellent performance， and optimizing the production process of organic peroxides.

In recent years， some halogen-based flame retardants have been gradually eliminated out for consideration of the environment， and phosphorus-containing flame retardants have received extensive attention as substitutes for halogen-based flame retardants. However， efficient phosphorus-based flame retardants usually produce more smoke while improving flame retardancy， therefore， they need to be used in combination with synergists. This paper introduced the flame-retardant mechanism of phosphorus-containing flame retardants in epoxy resin. The latest research progress of synergists， including inorganic， organic， and organic-inorganic hybrid synergistic agents， with phosphorus-based flame retardants in epoxy resin was summarized. We look forward to the future development trend of the synergistic system of phosphorus-containing flame retardants in epoxy resin.

Proton donors or acceptors are important participants in several important electrocatalytic reactions， it has been proved that species and concentration of proton donor/acceptor can induce significant impact on the electrocatalytic reaction rate and even product species. Starting from the demonstration of typical reaction mechanisms of electrocatalytic hydrogen evolution， electrochemical reduction of carbon dioxide， electrocatalytic oxygen evolution and alcohol electrooxidation to produce aldehyde/ketone， this mini-review summarized proton donor/acceptor species and proton transfer pathway etc. in these four electrocatalytic reactions， and discussed their effects on the efficiency of the electrocatalytic reactions.

Polygalolide A and B are two new phenolic compounds isolated from the rhizome of the medicinal plant Polygala Falax Hemsl. They have a complex tetracyclic cageframe work， including a highly oxidized cycloheptanone， three oxygen-containing heterocycles and two adjacent bridge carbon centers. This review summarizes the central tetracyclic was constructed by （5+2） cycloaddition， intramolecular （3+2） cycloaddition and intramolecular nucleophilic substitution. These lay a foundation for the study of the molecular biological activity

Capacitive deionization （CDI）， an emerging method for water desalination and ion separation， has received much attention due to its advantages of high ion selectivity， high water recovery and low energy consumption. Compared with the traditional carbon electrodes， the emerging Faraday electrode offers a unique opportunity to make the desalination performance of CDI significantly improved through the Faraday reaction of ion capture. Transition metal-based electrodes have received much attention in the field of CDI electrode design due to their highly reversible Faraday response， relatively high conductivity， and excellent theoretical pseudocapacitance values. In this paper， we systematically summarize and sort out the material classification of transition metal-based electrodes in CDI applications， and summarize the modification engineering performed for their intrinsic defects， mainly including conductive material coupling， functional architecture engineering and defect engineering， etc.， and summarize their performance in CDI applications； in addition， the specific applications of transition metal-based electrodes in CDI are particularly introduced in terms of ion selective separation， metal ion removal and nutrient element recovery. Finally， the paper also outlines the remaining challenges and research directions to provide guidance for future development and research of transition metal chemical substance electrodes.

Rubber and plastic materials are commonly used in the manufacturing of athletic shoes. This paper summarizes the basic properties of natural rubber， styrene butadiene rubber， nitrile rubber， neoprene rubber， butadiene rubber， recycled rubber， polyvinyl chloride， polyolefin elastomer， styrene-butadiene-styrene elastomer， vinyl acetate copolymer， polyurethane， block polyetheramide resin and other materials in the manufacturing process of athletic shoes. The research progress of related rubber and plastic materials in recent years is reviewed. It is pointed out that the rubber and plastic materials for athletic shoes will be developed towards lightweight， functionality， intelligence and environmental-benign in the future.

Dye-containing wastewater， largely discharged from the textile or printing industries， is one of the well-known sources of water pollution， posing great threats to both human health and the living environment. Although several water treatment technologies including physisorption， chemical oxidation， and biodegradation have been developed， most of them are costly and may produce some by-products with unknown toxicities. Therefore， it is highly desirable to develop economic and effective treatment technologies to reduce water resource consumption and protect the environment. Photocatalysis is a method in that highly reactive transitory species such as superoxide or hydroxyl radicals can be generated by reacting oxygen or water with photocatalysts upon irradiation of light， then degrading the organic dyes. Because the whole photocatalysis process has no chemical input and no secondary pollutants， it is considered to be an environmentally friendly， energy-efficient， and sustainable technique. In this paper， we have reviewed different kinds of photocatalyst systems developed in recent ten years for the degradation of organic pollutes， which cover inorganic semiconductors， metal-organic frameworks， organic small molecules， and conjugated porous polymers. Based on the large surface area and high photocatalytic activity， the conjugated porous polymers can simultaneously adsorb and photodegrade organic dyes under visible light， exhibiting stronger developmental potential compared with other photocatalytic materials.

Two-photon fluorescence has the advantages of large penetration depth and high spatial resolution， and has an important application prospect in the field of biological imaging. With the continuous innovation and development of related research， organic dipole and quadrupole molecules cannot exhibit the desired two-photon excited fluorescence properties due to the limitations of their own structure and properties， and cannot be designed and regulated in their structure properties. So it is increasingly unable to meet the needs of practical applications. Compared with organic dipole and quadrupole molecules， organic octupolar molecules have obvious advantages in this aspect. Through the diversified structural “clipping” on the multiple structural units （central core， branches and π-conjugate bridges）， the coupling between different branches can be greatly improved and the two-photon absorption cross section can be also improved. At the same time， the water solubility， membrane permeability， biocompatibility and laser stability of the molecule can be further optimized. Therefore， in recent years， more and more research has focused on organic octupole two-photon excited fluorescence materials. The research progress in design， synthesis and properties of organic octupolar two-photon excited fluorescence materials in recent five years is reviewed. The discussion focuses on the design and synthesis of novel central core structure， the improvement of two-photon absorption response of organic blue two-photon excited fluorescence materials， the improvement of photostability and water solubility of two-photon excited fluorescence materials， and the expansion of excitation wavelength from near infrared region 1 to near infrared region 2. The further development trend of this field is also discussed， which provides a basis for the further development and application of organic octupolar two-photon excited fluorescence materials.

Bacteria in water will pose a certain threat to the environment and human health， and traditional fungicides may cause secondary pollution and have poor stability and other problems. Seeking more efficient， environmentally friendly and reliable bacterial inactivation methods to gradually replace traditional disinfection methods has become an important research direction in the field of water treatment. In recent years， many academic researchers have actively explored natural polymer flocculants with antibacterial function. These materials are based on natural polymer compounds such as chitosan， starch and lignin， which not only show environment-friendly， widely sourced and renewable characteristics， but also have high modification potential to meet the needs of complex practical applications. This review describes in detail the latest research progress and application status of natural polymer flocculants with antibacterial function. The contents covered include substrates， modification methods， grafted monomers， flocculation properties and flocculation mechanism， antibacterial properties and antibacterial mechanism， etc. In addition， this review looks at future research directions on how to further optimize the performance of these polymer flocculants to meet the increasingly complex water treatment needs， while providing an academic perspective on future research. This series of research work provides profound connotation and theoretical support for further exploring the academic research of natural polymer flocculants with antibacterial function.

The low hot melt adhesive strength of ethylene vinyl acetate （EVA） as a matrix resin is mainly due to its low cohesive strength and low polarity on the bonding surface. To address this issue， polar vinyltri（2-methoxyethoxy）silane （VT2MES） is grafted onto the EVA main chain through a melt grafting method， resulting in the synthesis of ethylene vinyl acetate grafted with vinyltri（2-methoxyethoxy）silane （EVA-g-VT2MES）. The molecular chain structure of the product is characterized using Fourier transform infrared spectroscopy （FT-IR） and nuclear magnetic resonance spectroscopy （NMR）， indicating that VT2MES hasbeen successfully grafted onto the EVA molecular chain， with the highest grafting rate of 2.37%. Rheology and melt index tests demonstrate an improvement in the cohesive strength of the grafted product. Adhesive films are prepared from EVA and EVA-g-VT2MES， and steel plates are bonded with them. Compared with EVA， the peel strength of EVA-g-VT2MES is increased by up to 75.21%， confirming that melt grafting of VT2MES onto the EVA molecular chain can significantly improve the adhesion strength of the EVA matrix.

The huge importance of sustainable energy makes the research of the green and environmental hydrogen energy active in the world. Energy conversion and storage technologies （such as fuel cells or water electrolysis） are capable of readily promoting the interconversion between hydrogen and electric power， for which the development of efficient and stable electrocatalysts is prerequisite. Ordered intermetallic compounds are considered as superior electrocatalysts for energy conversion storage technologies and ideal models for studying the relationship between catalytic activity and structure due to uniform distribution of active sites on surface， well-defined stoichiometry and the better control of the local geometry and electronic structure of metal atoms， compared to disordered alloys as their counterparts. In this review， the challenges of catalysts with regard to hydrogen-electric conversion and the advantages of intermetallic compounds in electrocatalysis are firstly introduced. Secondly， research progress on intermetallic compounds electrocatalysts applied in the interconversion between hydrogen and electric power is mainly discussed from the perspective of activity and stability. Finally， the future development prospects of intermetallic electrocatalysts are summarized and prospected.

Oxygen reduction reaction is a crucial process for fuel cells. Conventional oxygen reduction catalysts are the precious metal platinum， but given the high cost of platinum， researchers want to find a low-cost alternative catalyst that is cheaper and has the equivalent catalytic activity to platinum. In previous studies， iron-nitrogen-doped graphdiyne and cobalt-nitrogen-doped graphdiyne have been studied， and they all show efficient oxygen reduction reaction activity， while nickel， with similar electronic structure with iron and cobalt， has not been studied. Therefore， in this work we design and synthesize various nickel-nitrogen-doped graphdiyne electrocatalysts using hydrogen as a substitute for graphiyne， and conduct redox electrochemical tests. The nickel-nitrogen-doped graphdiyne catalyst containing 2% nickel and melamine shows the best electrocatalytic performance for oxygen reduction. We conduct a series of physical characterizations for the catalysts： X-ray diffraction （XRD）， X-ray photoelectron spectroscopy （XPS）， transmission electron microscope （TEM）， scanning electron microscope （SEM） to further analyze their structure and morphology. It can be seen from the physical characterization and electrochemical tests that nitrogen atoms are the key to construct the catalytic active site， and nickel atoms play a vital role in improving the performance of the catalysts. With the synergistic effect of nitrogen and nickel， the nickel nitrogen-doped graphdiyne catalyst shows excellent catalytic performance， which makes it have a good application prospect.

Due to excellent physical and chemical properties， precious metals are widely used in various fields of national economy and national defense construction， and are extremely important economic and strategic resources. In recent years， due to the rapid growth in the demand for rare and precious metals， the contradiction between supply and demand has become increasingly serious. Therefore， it is very important to selective recovery of precious metals from secondary resources such as electronic waste with high precious metal content. Ion-imprinted polymers （IIPs） are widely used in solid phase extraction， preconcentration， water treatment， membrane separation and electrochemical sensors due to the advantages of simple preparation， cavity fixation， structural stability， good environmental adaptability， high regeneration capacity and selectivity for template ions. In this paper， the research progress of ion imprinting technology in the recovery of precious metals at home and abroad in recent years is reviewed， the preparation process and its application are introduced， and the current problems and future development directions of precious metal ion imprinting technology are analyzed and prospected.