Solar driven photocatalysis is an effective method to prepare clean fuels，degrade pollutants and convert high value-added products to solve the problems of energy shortage and environmental pollution.With the further study of metal halide perovskite，researchers have successfully developed a series of synthesis methods which can prepare perovskite quantum dots with precise composition and morphology control，good product uniformity and high crystallinity，so that perovskite quantum dots can be applied to the field of photocatalysis.The synthesis methods of metal halide perovskite quantum dots by thermal injection，ligand-assisted reprecipitation，solvothermal method and microwave assisted method were reviewed，and the research progress of metal halide perovskite in the aspects of photocatalytic hydrogen evolution，photocatalytic reduction of CO₂，photocatalytic synthesis of organic matter and photocatalytic degradation of organic matter were discussed.Finally，the development prospect of metal halide perovskite photocatalyst was prospected.

Lithium resources are important national strategic resources,which are widely used in many fields such as new energy vehicles,electronic products,and energy storage.China is rich in lithium resources.Among them,salt lake brine lithium resources are mainly distributed in Qinghai and Tibet.However,due to factors such as the low grade of salt lake brine itself,low extraction efficiency of lithium salt and limited production capacity,it has not been effectively developed,resulting in a serious dependence on foreign lithium products.Therefore,in order to ensure the continuous and safe supply of lithium resources in China,it is of great significance to break through the lithium extraction technology from salt lakes and explore more green,efficient and low-cost extraction technologies for the utilization of lithium resources in salt lake brines.The general situation of lithium resources in salt lakes,the characteristics of salt lake brine,and the latest research progress of efficient separation and extraction of lithium resources were systematically introduced.Finally,the research focus of lithium resources separation and extraction technology was prospected.

The recent research on modified lithium iron phosphate（LiFePO₄） materials as lithium-ion electronic cathode materials was reviewed.Although LiFePO₄ were considered to be the most promising cathode materials for lithium-ion power batteries due to their good stability，high safety and environmental friendliness，their inherent low electronic conductivity and lithium-ion diffusion coefficient deteriorated their electrochemical performance.The study on modification to improve their electrochemical performance was reviewed in this paper.The effects of four modification strategies including elemental doping，surface carbon coating，particle nanosizing and materials compositing on the electrochemical performance of LiFePO₄ were analyzed.Then，the advantages and disadvantages of these four modification strategies were discussed.The analysis showed that the four modification strategies could effectively improve the Li-ion diffusion kinetics and electronic conductivity，but the surface carbon coating and particle nanosizing would conversely reduce the tap density of the materials，resulting in low energy density.Finally，the research direction to solve the existing problems was proposed that it would be a feasible method to develop a modification strategy with coexistence of battery and capacitive properties.

The amount of waste salt in China is large，the source is wide and difficult to be treated，so it is of great significance to study the recycling and disposal of waste salt.The sources，classification and properties of chemical waste salt were summarized，and the current treatment and disposal policies and problems of waste salt were listed.The disposal technology and research progress of waste salt in pesticide，medicine，printing and dyeing，coal chemical industry and epoxy resin five high-yield industries were discussed.In order to provide some reference for the recycling of waste salt in related industries，the new ideas of classifying resource utilization according to different industries，improving the removal rate of organic matter and conversion efficiency of chemical reaction，and realizing source emission reduction and raw material recovery and reuse were put forward.

In recent years,the rapid development of new energy vehicles and energy storage technology driven by the new energy industry,has led to rapid growth in lithium salt consumption.At present,the global lithium salt industry is booming,and in the process of staking and rapidly expanding production.China has abundant lithium resources,especially in salt lake brine.Through years of technical research and industrialization practice,the lithium extraction technology from salt lake brine of China is gradually matured,and new technologies are emerging.Under the background of the hot global lithium salt market,lithium salt lake of China has the potential for rapid expansion.The lithium extraction technologies from salt lake brine that had been successfully industrialized in China were introduced,the advantages and disadvantages of each technology were analyzed,the new lithium extraction technologies that were under research and expected to achieve industrial application were discussed,and the development direction of lithium extraction technology from salt lake brine was judged.From the perspective of green and efficient lithium extraction process,the future development trend of lithium resource supply from salt lake was analyzed and prospected.Through the research,it was expected to have a clearer understanding of the technical status and technical development direction of the domestic lithium extraction industry from salt lake,and to provide the technical reference for the development of lithium salt lakes at home and abroad in the future.

The source，water quality characteristics and hazards of high-salt wastewater were introduced，and the principles，research and application progress of high-salt wastewater treatment technologies such as thermal concentration treatment technology，membrane separation treatment technology，membrane concentration treatment technology，and combined treatment technology were systematically analyzed.By comparing the advantages and disadvantages of different high-salt wastewater treatment technologies，it was concluded that the key to the development of high-salt wastewater treatment technology was to make full use of latent heat or develop clean energy，prepare or improve new anti-pollution membrane materials，extract and domesticate halotolerant bacteria and halophilic bacteria.It was proposed to simplify the treatment process，speed up the research and application of coupling technology，and develop new efficient and environmentally friendly treatment materials as the development direction of high-salt wastewater treatment technology.

Barium titanate?based electronic ceramic materials are widely used in capacitors，integrated circuits，sensors，thermistors and other fields.Industrial requirements such as capacity，miniaturization，breakdown resistance，and low loss put forward higher requirements for the performance of barium titanate?based electronic ceramic materials.Modification is the main mean to improve the performance of ceramic materials.The research progress on barium titanate?based electronic ceramic materials in doping modification，composite modification and physical modification in recent years was reviewed.The problems in the modification of barium titanate based electronic ceramics，such as insufficient optimization of preparation parameters of conventional elements，fewer types of rare earth elements，cladding effect to be improved，poor comprehensive performance of polymer ceramic composites，and sintering process to be optimized were analyzed.Solutions were proposed，such as exploring multiple element doping，optimizing process parameters，improving coating and polymerization methods，etc.The future development direction of barium titanate based electronic ceramic materials was pointed out.It was strengthening research of the mechanism of grain size，crystal shape and component regulation in the sintering process，selecting more rare earth elements for modification，and exploring new processes such as coating doping modification and polymer composite modification.

Lithium is a core element to support the strategic development of new energy，whose extraction and supply are closely related to the national economy.For the targets of carbon peak and neutrality，the demand of lithium and its compounds is rising rapidly in China，while China has become the largest lithium consumer with high external dependence in the world.Lithium is mainly deposited in ores and salt lake brines，which is the top priority for lithium resource exploitation worldwide.Besides，the utilization of the secondary lithium resources in urban mines is showing great potential for the development of recycling concept and technology.The industrial methods and research progress of lithium extraction from hard rock lithium minerals，salt lake brines and retired lithium-ion batteries were summarized.Among them，lower consumption and carbon reduction were the development direction of lithium extraction process from hard rock minerals.The lithium brine extraction technology should be tailored to local conditions，then make a specific method of the lake，and the combination of multiple separation technologies should be the best choice for future engineering construction.It was essential to focus on the research of re-preparation technology of retired lithium-ion battery，which could significantly reduce the dependence of lithium-ion battery manufacture on natural resources，and it was an indispensable part of the sustainable development of new energy strategy.

The source，water quality characteristics and hazards of wet desulfurization wastewater were introduced and the principles，research and application progress of wet desulfurization wastewater treatment technologies such as traditional treatment technology，concentration reduction technology，solidification technology，and resource utilization technology were systematically analyzed.Comparing the advantages and disadvantages of different wet desulfurization wastewater treatment technologies，it was proposed that the chemical precipitation method was mature and widely used，but the effluent had high salt content and heavy metal content and could not be reused，which was likely to cause secondary environmental pollution； advanced treatment technologies such as concentration reduction，solidification，and resource utilization could effectively reduce heavy metal content.organic pollutants，and recover some valuable components，which could meet the requirements of zero discharge of wastewater，but the process was generally immature，and most of them were in the laboratory research stage.In view of some problems such as immature treatment technology，insignificant economic effect and slow industrial application，it was believed that front-end reduction and back-end resource treatment were the main goals of future development of wet desulfurization wastewater treatment technology.

Zinc oxide nanoparticles are a kind of novel inorganic functional materials，which are widely used in various fields such as rubber，coating，and catalysis.The liquid-phase synthesis techniques for zinc oxide nanoparticles have the advantages of easy control of particle size and morphology，low economic cost and feasibility for industrial-scale production.A comprehensive review was conducted on liquid-phase methods for the synthesis of zinc oxide nanoparticles，including microemulsion，sol-gel，hydrothermal/solvothermal，and chemical precipitation methods.The basic principles and key influencing factors of each method were elucidated.The crucial role of process intensification techniques in the preparation of zinc oxide nanoparticles were emphasized.Furthermore，a novel approach of “bubble-liquid film method” was introduced.This method involved the rapid mixing of surfactants with the reaction solution and air to create a nanoscale reaction environment with high bubble density.The nucleated crystals grew within a liquid film of 10 to 100 nm between bubbles.By controlling the thickness of the liquid film between bubbles，the particle size of the product could be regulated，leading to uniform and non-agglomerated nanoparticles.This approach was expected to achieve low-cost，continuous，and large-scale production of zinc oxide nanoparticles.

LiFePO₄ battery is highly favored for its′excellent cycling performance，relatively low price and high stability.The cyclic curve faded rapidly in the early stage，and flattened out in the middle and late stages.In order to explore the potential capacity of LiFePO₄ battery for longer service life，LiFePO₄/graphite battery was taken as the research object to study the early cycle with fast decay，and suggestions for improvement were put forward based on the research results.Compared with the ternary（NCM） cell，the differences of initial efficiency of the anode material caused the cycle attenuation of LiFePO₄ material to be faster than that of the ternary material.This theory had been confirmed by means of inductively coupled plasma emission spectroscopy（ICP），X-ray diffraction（XRD），etc.The SEI films were characterized by inductively coupled plasma emission spectroscopy（ICP），energy dispersive spectroscopy（EDS） and differential scanning calorimetry（DSC）.It was proved that the main reason for the fast decay of LiFePO₄ in the early stage was the consumption of active lithium，and the loss of active lithium was mainly used to repair the damaged SEI film.Finally，the decay rate of the LiFePO₄ battery in the early stage could be slowed down by improving the OI value of the negative particles，the coating amount of the cathodes，the swelling of the negative gel，and the specific surface area of the anodes.

The performance of lithium-ion battery cathode materials is the development bottleneck of lithium battery technology.Recently，alumina（Al₂O₃） coated cathode materials have been widely studied in order to improve the cycle life，thermal stability and multiplier properties of lithium-ion batteries.The Al₂O₃ coatings were divided into three different forms of namely rough，ultra-thin and thick coatings.The role of Al₂O₃ surface coatings in improving cathode material performance was briefly discussed，such as HF scavenger，physical protective barrier，increasing lithium ion diffusion rate，improving thermal stability of cathode material，reacting with LiPF₆ to form electrolyte additive LiPO₂F₂ and inhibiting Jahn-Teller effect，etc.The surface modification methods were introduced，including impregnation method，precipitation method，dry coating process，sputtering method and atomic layer deposition method，etc.and its influence on the cathode materials of lithium cobaltite（LiCoO₂），lithium manganite（LiMn₂O₄），lithium iron phosphate（LiFePO₄） and ternary material（Li-Ni-Co-Mn-O）.At last，the development trend of Al₂O₃ surface coating and atomic layer deposition technology was prospected.

Due to human activities and natural reasons，heavy metal pollution has become a global problem.The adsorption method is a highly operable and large-scale technology，so it is urgent to develop adsorbent with high selectivity and high adsorption capacity.Layered double hydroxides are typical anionic clay layered materials，which have been widely used in the field of heavy metal pollution control due to their adjustable composition of laminates，interlayer anion exchange，structural memory effect and other characteristics.The work of high-value conversion of magnesium resources in salt lakes to prepare magnesium-based hydrotalcite materials and their application in the treatment of heavy metal pollution were summarized，the application progress of magnesium-based hydrotalcite in the in-situ remediation of heavy metal contaminated farmland was introduced，the problems existing in the process of ultra-stable mineralization were discussed and suggestions were put forward，and finally the application prospect of magnesium-based layered double hydroxides was prospected.

Bimetallic-organic frameworks materials（BMOFs） have been widely studied in many fields of catalysis，biosensing，energy storage due to their large specific surface areas，high porosities，synergistic effects，controllable components and morphologies，and easily design and synthesis，etc.The preparation of BMOFs with several common methods were reviewed.Their designed and controllable morphologies were introduced.The stability of the composition and morphology before and after modification was discussed.The application performance and advantages of BMOFs in the fields of catalysis，sensing and energy storage were briefly described.The results showed that the large specific surface areas，the synergistic effects of bimetals，the controllable multi-components and morphologies of BMOFs were favor to the improvement of porosities，active sites，electron transfer rates and properties.And the challenges and problems were analyzed，such as low electrical conductivity，synthesis method，and insufficient maturity in precise design and regulation.Finally，the prospects based upon the above shortcomings of BMOF were proposed.

As countries around the world are vigorously developing the new energy vehicle industry，the number of power batteries，mainly of lithium-ion batteries（LIBs），has increased rapidly.However，LIBs have limited lifespan，and the early installed LIBs have met their retired requirements in recent years.There is an urgent need for effective recycling of the large number of decommissioned batteries，which would otherwise cause issues to the environment and human beings，as well as lead to the loss of precious metal resources.Traditional battery recycling technologies，mainly of pyrometallurgy or hydrometallurgy，can realize the fine recovery and reuse of various components of retired LIBs，but are usually polluting，energy intensive and long recovery cycle.Therefore，it is urgent to develop green，energy-saving and efficient LIBs recycling technology.In recent years，the emerging direct regeneration technology has attracted much attention due to its advantages of simple process，low carbon emission，low energy consumption and short recycling cycle.The several current mainstream direct regeneration technologies for cathode materials and their advantages and disadvantages were reviewed，their contributions in term of low cost and low energy consumption were analyzed and the functionalization of cathode materials and the latest development of LIBs closed-loop recycling was introduced.Finally，the prospects and development trends of the recycling of retired LIBs cathode materials and other components were forecasted，aiming to provide a reference for the field of battery recycling.

Propylene is an important industrial raw material mainly used in the production of polypropylene，acrylonitrile，isopropyl alcohol，acetone and propylene oxide.With the increasing demand for propylene，the technology of propane dehydrogenation has been widely used in the industrial production of propylene.Although platinum-based and chromium-based catalysts have high activity in propane dehydrogenation，they are also prone to poisoning and deactivation.Metal oxides have attracted widespread attention as alternative non-precious metal catalysts.Firstly，the reaction pathway and deactivation mechanism of propane dehydrogenation catalyzed by metal oxides were introduced.It was pointed out that enhancing the C—H activation ability，alleviating the reconstruction and reduction of active components were the key to improving the propane dehydrogenation performance of metal oxide catalysts.Then，several representative metal oxide catalysts were reviewed in detail，the mechanism of action and active species of various catalysts were summarized，and the existing problems of corresponding catalysts were analyzed and discussed.Finally，key research directions for future propane dehydrogenation catalysts were proposed，which was expected to provide new ideas for the direct production of chemicals through the activation of low-carbon alkanes.

Fe₂P is a common by-product during the generation of lithium iron phosphate（LiFePO₄，LFP），and its effect on the electrochemical performance of LFP has not been thoroughly studied so far.The effect of adding different proportions of Fe₂P into LFP by ball milling method on the electrochemical performance of LFP cathode materials was explored.The results showed that after doping Fe₂P，the crystal structure of LFP material remained unchanged，the particle morphology was highly organized，and the distribution of major elements was uniform.Additionally，the ion and electron conductivity of LFP material were improved to varying degrees.Especially，when the Fe₂P doping amount was 0.5%（mass fraction），the first discharge specific capacity reached 158.2 mA·h/g and 148.5 mA·h/g at 0.1C and 0.5C magnification，which were 8.90% and 7.2% higher than pure LFP，respectively.The difference in redox peak potential in CV curve（ΔE） was only 0.264 V，indicating that the introduction of Fe₂P was beneficial for improving the polarization of LFP materials，and the high overlap of the first three CV curves indicated that the material had a high degree of reversibility.The charge transfer resistance（R_ct） was only 41.56 Ω，which was 76.49% lower than pure LFP.The diffusion coefficient of lithium ions was 8.20×10^-9 cm²/s，which was 89.4% higher than pure LFP.At the same time，the improvement on rate capability and cycling performance was significant.

The lithium brine is an important raw material for lithium battery and energy storage materials，and also the strategic resources of the country.Demand for lithium has prompted researchers to expand lithium extraction from conventional salt lake brines to unconventional sources such as oilfield brines and geothermal brines.At present，the lithium extraction technology of conventional brines has been successfully applied in industrialization worldwide，while the lithium extraction technology of unconventional brines is still in the stage of industrialization development，and a large number of lithium resources in brines have not been developed and utilized.Based on the information of lithium resource distribution and composition in unconventional brines，the research status of direct lithium extraction technology in unconventional oilfield brines and geothermal brines was analyzed，and the main lithium extraction technologies，such as precipitation，membrane separation，solvent extraction and adsorption were systematically studied.In addition，the industrialization status of lithium extraction technology of unconventional brines at home and abroad was summarized，and the future lithium extraction technology of unconventional brines was prospected，which was expected to provide reference for the green and efficient development of lithium resources of geothermal brines and oilfield brines.

Coated catalyst exhibits both the advantages of high strength of support and high reaction performance of catalytic coating，which has been widely concerned at home and abroad.Coating process plays a key role in the preparation process of coated catalysts，which has an important influence on the performance of the catalysts.Several common coated catalyst forming methods such as dip coating，spray coating and roll coating were summarized.The characteristics of catalyst support，forming additives and coating processes and the applications in catalytic reactions were introduced.On the basis of summarizing the important effects of coating process on catalyst forming effect，coating properties and product reaction performance，it was proposed that the coating process should be further optimized in the future to broaden the application scope of coating process.

Red mud is the polluting waste residue discharged from the aluminum industry to extract alumina.Improper treatment will cause great harm to the ecological environment.The chemical composition，phase composition and production path of red mud were introduced and the main processes and characteristics of recovering iron，aluminum，titanium，scandium and other metal resources from red mud were analyzed.It was elaborated that adding appropriate amount of red mud could enhance the mechanical properties and fire resistance of building materials，solidify the radioactive elements in red mud，and reduce environmental pollution.In addition，the preparation of geopolymer materials，glass-ceramics，composite materials and other processes were not yet mature.It was still necessary to seek efficient target metal purification technology and efficient and rational disposal method of waste residue and waste liquid，and develop a complete set of red mud development and application process.