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.

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.

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.

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.

The production and lifestyle of human society have resulted in severe water pollution，with organic pollutants，bacteria，and heavy metal ions causing significant harm to the ecological environment and human health，which has become one of the most pressing issues to be addressed by humanity.In recent years，molybdenum-based catalysts have garnered widespread attention in the field of water pollution control due to their unique electronic properties and morphological characteristics.The application progress of different molybdenum-based catalytic materials in the field of water pollution control was reviewed.The research progress of different molybdenum-based catalysts for the removal of organic pollutants from water，disinfection and removal of heavy metal ions by means of photocatalytic，Fenton-like and adsorption techniques was summarized.The challenges associated with the current molybdenum-based materials in water pollution control technology were also discussed.Additionally，the modification methods to improve the adsorption and catalytic performance of molybdenum-based catalysts were also discussed，which provided a feasible research direction for the design of highly efficient and stable molybdenum-based catalysts in the future.

The rapid development of the new energy industry drives the rapid growth of the lithium battery industry.As the power battery type with the highest market share，lithium-ion batteries have been widely used in various industries，However，with the decline of battery performance，they will face a huge problem of recycling and processing waste batteries within the foreseeable recycling cycle.The common types and structures of lithium ion batteries were briefly described，and different recycling methods for waste lithium-ion batteries were introduced.According to the relevant research status at home and abroad，the pretreatment process of waste lithium-ion batteries and the recovery and treatment technology of electrolytes were elaborated，the research progress of pretreatment and electrolyte recovery treatment technology was summarized，the applicability and characteristics of different methods were discussed，and the prospects and development directions of the waste lithium-ion battery recovery industry were provided.

Potassium resources are scarce in China and the supply of potash fertilizer concerns the security of agricultural food.An important and largest production base of potassium chloride has been built in Qinghai，China.How to develop and utilize potassium resources sustainably is crucial to ensure the security of the national potash fertilizer supply.The salt lake potassium resources status in Qinghai was listed，the chloride type of salt lake potassium resources research advances of Qinghai in exploration and exploitation in recent years were introduced，and technological improvement of three kinds of the main flowsheet were summarized，including cold decomposition-direct flotation，cold crystallization-direct flotation，and reverse flotation-cold crystallization.Moreover，the key technology development tendency of salt lake potassium resources future guaranteeing supply of Qinghai was prospected，which included the deep exploration of potassium resources，efficient utilization of potassium resources，and effective exploitation of middle-western magnesium sulfate subtype salt lakes potassium resources and efficient exploitation technology of poor mixed potassium ore resources，etc.

The process of extracting Ni，Co and Mn from the filter residue of preferential extraction of lithium from retired ternary power lithium battery was studied.Using extractant（C₈H₁₇O）₂PO₂H（P204） under the following processing conditions such as extraction pH of 3，extraction V（O）∶V（A）=1∶1，extraction time of 15min，extraction order of 3，salt washing V（O）∶V（A）=1∶2，back extraction V（O）∶V（A）=1∶0.5，back extraction time of 15min，back extraction order of 3，the recycling rate of Mn was 98.6%，while the purity of MnSO₄ was 99.5%.Using extractant（（C₈H₁₇）₂PO₃H（P507） under the following processing conditions such as extraction pH of 4.5，extraction V（O）∶V（A）=1∶1，extraction time of 10 min，extraction order of 2，salt washing V（O）∶V（A）=1∶2，back extraction V（O）∶V（A）=1∶0.5，back extraction time of 10 min，back extraction order of 2，the recycling rate of Co was 96.5%，while the purity of CoSO₄ was 94.9%.After impurities in Mn，Co raffinate were removed with（C₈H₁₇）₂PO₂H（C272） extractant，the recovery rate of Ni was 96.5%，while the purity of NiSO₄ was 97.3%.The battery cathode materials was regenerated by the extracted battery raw materials and their crystal structure，physical properties，electrochemical properties were tested.The results showed that the relevant performance indexes of the synthesized cathode materials met the YS/T 798—2021“Lithium nickel cobalt manganese oxide”industry standards and were qualified to enter the battery industry.

With the rapid expansion of industries such as the electric vehicle industry，the demand for lithium raw materials has increased dramatically.Ore lithium resources are on the verge of exhaustion，while salt lake brine has rich lithium resources with low mining difficulty，which has quickly become a hot spot in lithium salt production and research.The distribution，water quality characteristics，and application of lithium extraction methods in salt lake brine resources in the world were summarized.The research progress of lithium extraction from salt lake brine by precipitation ， extraction ， adsorption ， membrane separation ， and electrochemistry was discussed from the aspects of reaction mechanism ， influencing factors ， and application effect . Among the existing technologies ，the membrane separation method and electrochemical method had the advantages of good separation effect and low energy consumption，thus showing broad application prospects.However，both the precipitation method and the extraction method had the problems of large dosages of chemicals and serious environmental pollution，while the adsorption method had shortcomings such as a slow adsorption process and easy dissolution of adsorbent ，thus resulting in great limitations in industry application.Finally，the development trend of lithium resources in salt lakes was prospected and suggestions for the subsequent optimization of the lithium extraction process were put forward.

The effects of initial digestion water temperature，stirring speed，water-ash mass ratio and pressurized digestion on the morphological structure，particle size and specific surface area of the reaction product calcium hydroxide were investigated by using industrial grade quicklime as raw materials，and the product calcium hydroxide was characterized by Malvern laser particle size distribution instrument，scanning electron microscope（SEM） and specific surface area analyzer.The results showed that the digestion rate was accelerated with the increase of the initial temperature of water，and when the stirring speed was 500 r/min，the initial temperature of water was 45~80 ℃，and the mass ratio of water to ash was 4∶1，the produced calcium hydroxide had the narrowest particle size distribution and the maximum specific surface area was 18.23 m²/g.When the initial temperature of digested water was 25~45 ℃，the morphology of the product calcium hydroxide showed a "dendritic" shape，and when the initial temperature of the digestion water was 65~80 ℃，the shape of product calcium hydroxide grew into “granular”.The pressurized digestion method could obtain a large specific surface area of calcium hydroxide and its shape was “petal-like”，and the maximum specific surface area was 29.32 m²/g.

Layered transition metal oxides are considered as one of the most promising cathode materials for sodium-ion batteries（SIBs） due to their high theoretical capacity and ease of synthesis，which have attracted widespread attention.The purpose of this article is to review the research progress on layered transition metal oxides as cathode materials for SIBs.Firstly，a brief overview of the structural characteristics and existing issues of layered transition metal oxide cathode materials was provided.The Na⁺ coordination configurations and diffusion paths in terms of P2 and O3-type layered transition metal oxide cathode materials were also introduced.In addition，considering the issues of irreversible phase transition during charge/discharge process，high air sensitivity，and insufficient electrochemical performance，the recent research results of P2 and O3-type layered transition metal oxides were summarized based on three types of modification methods：component regulation，structural design，and surface coating.Finally，the future industrial development and potential research directions of layered transition metal oxide cathode materials for SIBs were prospected.

Photocatalytic CO₂ reduction， as a new green technology， is expected to simultaneously solve the energy crisis and environmental pollution problems，so it has attracted much attention in recent years.As one of the most widely studied photocatalysts， TiO₂ still has the disadvantages of limited light absorption range and rapid recombination of photogenerated carriers.Cu can be doped into TiO₂ with hollow structure by pyrolyzing Ti-based MOF（metal-organic framework） precursors.The structure and morphology of the as-prepared photocatalysts were analyzed by X-ray diffraction（XRD），scanning electron microscopy（SEM），and transmission electron microscopy（TEM）.In addition， the structure-activity relationship was investigated using UV-Visible diffuse reflection spectroscopy（UV-Vis DRS） and photoluminescence spectroscopy（PL）.The experimental results revealed that Cu doping could improve the light absorption capacity and promote the separation of photogenerated carries， thereby improving the performance in photocatalytic CO₂ reduction.When Cu doping mass fraction was 0.50%，the catalyst exhibited the best performance，and the yield of CO and CH₄ reached 6.3 μmol/g and 1.6 μmol/g， respectively.

As the primary industrial by-product of gypsum，phosphogypsum could be prepared by calcination to obtain building material gypsum powder.The characteristics and advantages as well as the disadvantages of existing phosphogypsum calcination processes at home and abroad were summarized.In view of the existing calcination processes such as frying pan，rotary kiln，boiling furnace，Peter grinding，FC-boiling furnace，hammer crushing and so on，there were some technical and equipment problems，such as unstable product quality，poor controllability，single function，high energy consumption and high investment，thereby the fluidized bed calcination process was proposed.The characteristics and technological innovation advantages with large-scale fluidization，product diversification，dry purification green and environmental protection were highlighted.Moreover，it was also compared with the current mainstream calcination process product performance index.It was analyzed that quality stability，controllability and performance index of the fluidized bed calcination phosphogypsum technology product were superior，which would become the future phosphogypsum preparation of building materials gypsum powder mainstream technology means.And it could provide guidance value for the calcination and resource utilization of phosphogypsum eventually in China.

The environmental problems caused by long-term storage of phosphogypsum are becoming increasingly prominent，and the harmless treatment and comprehensive utilization of phosphogypsum are urgent.The research progress of phosphogypsum in the fields of preparing industrial gypsum and building materials，cement retarders，preparing sulfuric acid co production cement，roadbed materials，filling materials，and soil amendments was summarized，the main research directions of phosphogypsum was introduced，the relationship between comprehensive utilization research and industrialization of phosphogypsum was analyzed.It was pointed out that the core contradiction between phosphogypsum research and industrialization was depended on the low value of phosphogypsum itself and the high cost of industrial treatment，which was unable to be promoted，and various solutions were proposed to address the above issues.It was pointed out that the future development of phosphogypsum would require government policy support and maintain a balance between the demand for phosphogypsum market and the addition of new devices.In terms of the utilization of phosphogypsum，harmless disposal was the foundation，roadbed materials were the main way to absorb phosphogypsum，and soil remediation and ecological restoration were new directions for phosphogypsum utilization.

In order to reduce the Pb²⁺ toxicity of CsPbBr₃ perovskite nanocrystals and optimize the luminescent performance of Sn²-doped CsPbBr₃ nanocrystals，Sn²⁺-doped CsPb_1-x Sn _x Br₃ nanocrystals（x=0.1，0.2，0.3，0.4 and 0.5） were synthesized by hot-injection method. The phase structure，microstructure and luminescent performance of the synthesized nanocrystals were characterized by X-ray diffractometer（XRD），transmission electron microscope（TEM），X-ray photoelectron spectroscopy（XPS），and photoluminescence spectrometer（PL）.The results showed that CsPb_1-x Sn _x Br₃ nanocrystals existed in the form of Sn²⁺ and Sn⁴⁺ ions，and contained Pb²⁺ cation vacancies. When x=0.3，the actual molar doping concentration of Sn element was as high as 43.91%. When x=0.1~0.4，the nanocrystals structure was pure monoclinic perovskite，the size was about 16~20 nm，and the square shape was uniform.The spectral properties of CsPb_1-x Sn _x Br₃ nanocrystals were regulated by Sn²⁺-doped. When x=0.3，the fluorescence emission peak of CsPb_1-x Sn _x Br₃ nanocrystals was located at 523 nm，the full width at half maxima（FWHM） was 15 nm，the fluorescence lifetime was as long as 86.3 ns，and the fluorescence intensity was the strongest，which were a kind of excellent green-light emitted semiconductor materials with potential application.

Hexavalent chromium is commonly used in traditional chromium electrodeposition process，which can produce toxic acid fog and other polluting substances，resulting in environmental pollution.Compared with hexavalent chromium，trivalent chromium electrodeposition technology has the advantages of lower energy consumption，less toxicity and less pollution，so it has a long term application prospect.Due to the different ion deposition modes in different bath systems，the electrodeposition mechanism of chromium trivalent has not been fully elucidated，especially the intermediate process and control steps of chromium ion reduction.Therefore，it is the key to solve a series of problems in the deposition process to study the plating solution system and electrodeposition mechanism of trivalent chromium in different plating solutions.Chromium electrodeposition process includes chromium electroplating and electrolysis.Based on the trivalent chromium electrodeposition process，the electroplating and electrolysis were summarized and analyzed from two aspects，focusing on the mechanism of chromium electrodeposition，the composition and component application of chromium plating solution，and diaphragm chromium electrolysis.Finally，the future research direction of trivalent chromium electrodeposition was prospected，such as further improving the membrane electrolysis device and studying the nonlinear non-equilibrium behavior of chromium during deposition.

The silver method and ferro-molybdenum method for producing formaldehyde by air oxidation of methanol were summarized and compared.Silver method was employed as the main technology of formaldehyde production in China for its maturity.Ferro-molybdenum method was more suitable for the planning and development of formaldehyde industry for its low methanol consumption，high formaldehyde yield，long catalyst life and good economic benefit.Nevertheless，domestic technology of ferro-molybdenum method was not mature.The research progresses of silver，ferro-molybdenum and vanadium catalysts were reviewed.Silver catalyst was difficult to be improved greatly.Ferro-molybdenum was researched as a hotspot，and vanadium catalyst was still far away from industrial application.Further study on reaction mechanism for performance improvement of ferro-molybdenum catalyst was proposed as an important subject of methanol oxidation to formaldehyde.The development of ferro-molybdenum catalyst which was more compatible with the existing silver method process was suggested as the main research direction of formaldehyde production technology in the future.

In view of the catalytic effect of CaO on gas production and tar reforming during biomass pyrolysis process，which can significantly improve the adsorption performance of biochar，the modified sludge derived biochar（BC-Ca） was prepared by co-pyrolysis of CaO and sewage sludge at a mass ratio of 1∶10.The effect of CaO on the characteristics of the sludge-derived biochar，as well as the speciation distribution of heavy metals（Pb，Zn，Cu，Cr，Mn） were investigated.The ecological risk of the biochar was assessed based on the risk assessment code（RAC）.The adsorption properties of the modified sludge derived biochar on Cr（Ⅵ） was evaluated by the static adsorption experiments.The results showed that compared with unmodified biochar（BC），the fraction of residual state（F4） of Zn，Pb，Cr，Mn，and Cu in BC-Ca were increased by 11.76%，13.03%，26.96%，5.55%，and 2.11%，respectively，which were all in a low risk condition according to the RAC standard.Compared with BC，the specific surface area of BC-Ca was increased by 122.99%，indicating that the microstructure performance of BC-Ca was improved.The adsorption behavior of BC-Ca for Cr（Ⅵ） was described by the Langmuir model and pseudo-second order dynamic sorption model，indicating that the adsorption capacity of BC-Ca was increased with increasing temperature，and the adsorption rate was mainly controlled by chemical adsorption mechanism.The maximum adsorption capacity of BC-Ca for Cr（Ⅵ） was improved by 51.13% than that of BC，showing outstanding removal effect on Cr（Ⅵ）.