With the rapid development of current society and economy, as well as the accelerated process of industrialization and urbanization, the complexity and seriousness of environmental pollution issues are becoming increasingly apparent. Beyond traditional pollutants, the appearance of emerging pollutants on a global scale has brought new challenges to environment and public health. China’s “14th Five-Year Plan” and medium and long-term planning put forward “emerging pollutant control”, report of the 20th National Congress of the Communist Party of China also explicitly requested “carry out emerging pollutant control”. In 2022, General Office of the State Council issued “Action Plan for Emerging Pollutant Control”, followed by the Ministry of Ecology and Environment and various provinces, municipalities, and autonomous regions, which released corresponding implementation plans, China has transferred to a new phase of environmental protection that balances the control of both traditional and emerging pollutants. However, management of emerging pollutants is a long-term, dynamic and complex systematic project, which urgently needs to strengthen top-level design as well as scientific and technological support. Conducting systematic research on emerging pollutants not only provides effective scientific guidance for their control and improves the level of environmental quality management, but also assists our country in fulfilling international conventions, enhances the discourse power in global environmental governance, ensures our country environmental security, food security, international trade security, etc., and is of great significance for realizing sustainable development. This review aims to comprehensively explore various aspects of emerging pollutants, including their types and characteristics, production, use and emission, identification and detection, environmental occurrence, migration and transformation, ecotoxicological effects, human exposure, health risks, and management strategies. Furthermore, it looks forward to the future research direction, with a view to providing a scientific basis and decision-making support for control of emerging pollutants in China.

Click chemistry won the Noble Prize in 2022 due to easy synthesis, high selectivity, single product, and no toxic side product. Click chemistry was originally designed as green chemistry to work in aqueous solutions or environmentally friendly organic solvents. However, due to the poor solubility of reactants, polar and toxic solvents are usually required to use. The solvent used violates the concept of green chemistry, as well as increases the cost. These issues hinder click chemistry to be a state-of-art green chemistry. One of the solutions to optimize click chemistry is to avoid using any solvent. Herein, ball-milled mechanochemistry does not limit reactants’ solubility and could avoid solvent use. Ball-milled mechanochemistry is a new kind of chemical reaction that is conducted in a ball mill, is induced by mechanical force, and needs no solvent or a minimal amount of solvent. As a new way of organic synthesis, ball-milled mechanochemistry could easily achieve the low-energy carbon-heteroatom bonds, which constitute the linkages in click chemistry. Therefore, it could integrate with click chemistry and achieves ball-milled click chemistry. In comparison to traditional solution click chemistry, ball-milled click chemistry avoids solvent use. Moreover, it is even superior in the ways that the reaction time is shortened, the reaction temperature is lowered, and the catalyst used is simplified. In this review, ball-milled click chemistry examples are reported as much as the authors can find, including CuAAc, Diels-Alder, amine and isothiocyanate reactions, amine thiol reactions, and nitroxide radical coupling reactions. To provide readers with a better ball-milled click chemistry manual, this paper also contains ball mill machine choice guidance, liquid-assisted grinding choice guidance, and factors impacting ball-milled click chemistry conversion, including catalyst choice, additive choice, ball choice, stoichiometry, and milling time.

The rapid advancement of large-scale energy storage devices has spurred the need for research focused on achieving higher energy density in lithium-ion batteries. Within this context, anode materials, which are crucial components of lithium-ion batteries, play a critical role in attaining enhanced energy density. Unfortunately, commercially available graphite anodes suffer from limitations such as low theoretical capacity, poor rate capability, and a low voltage plateau. Consequently, there is an urgent requirement to develop alternative anode materials that can meet these demands. Electrospinning has emerged as a popular method for fabricating electrode materials due to its simplicity, cost-effectiveness, and ability to produce flexible nanofibers. This technique offers several advantages, including the ability to tailor nanomaterials with diverse morphologies by adjusting key parameters. Furthermore, electrospinning enables the creation of nanomaterials with large specific surface areas, high mechanical strength, flexibility, and self-supporting properties. Consequently, it has garnered significant interest in the field of anode material preparation for lithium-ion batteries. This paper aims to provide an overview of the research progress in utilizing electrospinning for the preparation of anode materials in lithium-ion batteries. It covers various categories of anode materials, including carbon-based, titanium-based, silicon-based, tin-based, and other metallic compound materials. Additionally, the paper outlines the future directions and potential advancements in the development of electrospun anode materials. By exploring the applications of electrospinning in anode material preparation, this paper contributes to the understanding and advancement of lithium-ion battery technology, offering insights into the potential of electrospinning as a versatile and effective technique for enhancing anode performance.

In recent years, organo-metal halide perovskites materials with ABX₃ crystal structure have shown promising application prospects in the field of photoelectric detection due to their optical and electrical properties such as adjustable bandgap engineering, high absorption coefficient and long carrier transmission distance. Especially, the hybrid perovskite prepared by pure Sn or Sn/Pb mixed cations have excellent near-infrared photoelectroresponse in the range of 760~1050 nm, showing many advantages such as high sensitivity, low dark current and high detection rate. To further broaden the near-infrared and infrared response wavelength range of perovskite, the researchers explored combining organic materials, crystalline silicon/germanium, Ⅲ-Ⅴ compounds, Ⅳ-Ⅵ compounds, upconversion fluorescent materials as complementary light absorption layers with perovskite to prepare heterostructures to construct wide-spectrum response near-infrared photodetectors. Based on the above research, this paper summarizes the current effective ways to broaden the spectrum range of perovskite photodetectors. At the same time, the future development prospect of perovskite material near infrared photodetector is prospected.

Contents

1 Introduction

2 Basic indicators of photodetectors

2.1 Device structure and working principle of photodetectors

2.2 Performance parameters of photodetectors

2.3 Strategy of broadening the spectrum response range of perovskites

3 Pb perovskite for near-infrared photodetectors

3.1 Polycrystalline perovskite materials

3.2 Single crystal perovskite materials

4 Narrow band gap Sn and Sn/Pb Mixed Perovskite- Based near-infrared photodetectors

4.1 Sn-based perovskite near-infrared photodetectors

4.2 Sn/Pb mixed perovskite near-infrared photodetectors

5 Perovskite/inorganic heterojunction near-infrared photodetectors

5.1 Silicon and other classic semiconductors

5.2 Graphene

5.3 Transition metal dichalcogenides

5.4 Ⅲ-Ⅴ compounds semiconductors

5.5 Ⅳ-Ⅳ compounds semiconductors

6 Perovskite/organic heterojunction near-infrared photodetectors

7 Perovskite/upconversion material near-infrared photodetectors

8 Application of near-infrared photodetectors

9 Conclusion and outlook

In recent years, electrocatalytic nitrate reduction (ENitRR) has attracted considerable attention in the synthesis of ammonia at ambient conditions. Compared to the traditional Haber-Bosch process for ammonia synthesis, ENitRR offers lower energy consumption and milder reaction conditions. The design and optimization of ENitRR electrocatalysts are crucial for nitrate deoxygenation and hydrogenation. Copper-based catalytic materials have been widely studied due to their unique structure, low cost, and excellent performance, making them highly promising electrocatalysts through various morphology and electronic structure modulation strategies. This article summarizes various effective design strategies using copper-based electrocatalysts as a typical example to enhance the ammonia production rate and conversion efficiency in ENitRR. It also introduces the reaction mechanism and the relationship between structural changes in Cu-based electrocatalysts and their performance. These strategies include morphology modulation, alloy engineering, lattice phase tuning, single-atom structures, as well as copper compound construction and composites with other materials. Finally, challenges faced by copper-based electrocatalysts are discussed along with future research directions that should be focused on in order to provide reference for researchers engaged in nitrate treatment in aqueous systems.

With the rapid development of radio waves and electronic information technology, the problem of electromagnetic radiation pollution is becoming more and more prominent, which has attracted wide attention around the world. In order to solve the problem of electromagnetic pollution, people are committed to researching and developing electromagnetic wave-absorbing materials with light weight, thin thickness, a wide frequency band, and strong absorption. Compared with traditional wave-absorbing materials, carbon-based composite wave-absorbing materials have excellent dielectric properties, special microstructure, good impedance matching and efficient wave-absorbing properties, and can effectively reduce the mass of composite materials, which has great development potential in the field of wave-absorbing materials, and has gradually become a research hotspot. In this paper, the basic absorption principle of electromagnetic wave is summarized from the aspects of impedance matching and loss mechanism, and the research progress of carbon-carbon, carbon-metal/metal oxide, carbon-ceramics and other kinds of carbon-based composite absorbing materials is reviewed. At the same time, the synthesis methods, absorption properties and attenuation mechanism of these carbon-based composite absorbing materials are reviewed. Finally, the shortcomings of carbon-based composite absorbing materials in electromagnetic wave absorption are discussed and possible solutions are put forward, and the future development direction of carbon-based composite absorbing materials is prospected.

Covalent organic frameworks (COFs) have become one of the research focuses currently in porous materials due to their excellent photocatalytic activity. Compared with other heterogeneous photocatalysts, COFs possess regular and controllable structures, large specific surface areas, uniform pore channels and good chemical/thermal stability. Additionally, COFs have suitable band structures, adjustable absorption range, and are easy to be functionalized and recovered/reused after the reactions. The advantages above surely endow COFs with potential value in fundamental researches and industrial applications. In recent years, the application of COFs in photocatalysis has gained rapid progress, especially in the field of photocatalytic organic transformations. Theses significant works have greatly promoted the development of COFs. In this review, numerous synthesis strategies for photo-functionalized COFs are briefly introduced, e.g., “bottom-up” strategy, post modification and combination method. Then, the photocatalytic reaction mechanisms mediated by COFs are condensed into two pathways, i.e., energy transfer and electron transfer. The latest research progress of COFs as photocatalysts in photocatalytic selective oxidation reaction (oxidation of amines to imines, preparation of sulfoxides through selective oxidation of sulfides, oxidation hydroxylation of arylboronic acids to phenols, and oxidation of N-aryl tetrahydroisoquinoline), reduction reaction (reductive dehalogenation, hydrogenation of nitrobenzene, and hydrogenation of styrene), coupling reaction (C-C cross-dehydrogenative coupling reaction, C−N cross-coupling reaction, and C−S cross-coupling reaction), cyclization reaction, polymerization reaction and asymmetric organic synthesis, etc., are succinctly outlined and discussed. Finally, the application of COFs in photocatalysis is summarized and prospected.

Sodium-ion batteries have shown great application prospects in the field of large-scale energy storage and low-speed electric vehicles due to their resource and cost advantages. Among various cathodes reported, layered oxide cathode materials have been widely investigated owing to their high theoretical capacity and simple synthesis method. However, many adverse reactions and phenomena such as structural instability and surface degeneration are prone to occur during its cycling process, especially at high voltage, which hinders its application in commerce. This article briefly reviews the mechanism of structural transformation, surface degradation, and oxygen loss of layered oxide cathode at high-voltage, focuses on the strategies to improve the high-voltage resistance of layered oxide cathode, and aims to provide reasonable insights for improving the high-voltage stabilization of layered oxide cathode materials and designing sodium-ion layered oxide cathode materials with high performance. Finally, the shortcomings of sodium-ion battery layered oxide cathode materials in modification and future research directions are also summarized.

Interfering with bacterial iron metabolism is a non-antibiotic antibacterial strategy that is not easy to cause bacterial resistance. In this review, firstly, an iron-blocking antibacterial therapy which can kill drug-resistant bacteria but not easily cause drug resistance is introduced. Then, the mechanism of iron-blocking antibacterial therapy is explained from the iron uptake pathway and heme uptake pathway of bacteria. In addition, the types, in vitro antibacterial properties, and in vivo therapeutic effects of the iron blocking antimicrobials based on gallium salts and gallium porphyrins are reviewed in detail. Finally, the future development and practical application of the antimicrobials based on iron-blocking mechanism are prospected.

Benefiting from high energy density and low cost, Ni-rich LiNi_xCo_yMn/Al_1-x-yO₂ materials have received great attention as promising cathode candidates for next-generation high-energy lithium-ion batteries (LIBs) that are widely used in electric vehicles (EVs). However, with an increased Ni content, Ni-rich cathode materials suffer from severe structural, chemical, and mechanical instabilities, seriously restricting their industrially safe application in power LIBs of EVs. In this review, primarily, the synthesis methods of Ni-rich cathode materials are summarized in detail, which include solid-state method, sol-gel method, hydrothermal method, spray-drying method, and co-precipitation method. Subsequently, the key failure mechanisms, including ion mixing and irreversible phase transition, residual Li species and interface side reactions, mechanical microcracks, and transition metal dissolutions, are thoroughly analyzed throughout the preparation, storage, and service of Ni-rich cathode materials, thereby clarifying various performance decay behaviors of materials. The modification strategies that cover ion doping, surface coating, core-shell/gradient materials, and single-crystal materials are systematically discussed for Ni-rich cathode materials, aiming at presenting conspicuous research progress and current shortcomings for the stabilization of Ni-rich cathode materials. Finally, this review presents a perspective toward future development and optimization for Ni-rich cathode materials, aiming at delivering a theoretical guidance for propelling its industrial safe application in high-energy LIBs.

Hydrogen peroxide (H₂O₂) is an important green oxidizing agent, but the main anthraquinone process for production thereof suffers high energy consumption and large safety risks. Artificial photosynthesis H₂O₂ from water and oxygen features safe, environmentally friendly and energy-saving characteristics and has gradually become a research focus. Covalent organic frameworks (COFs) have been widely used in the photocatalytic production of H₂O₂ for their high specific surface area, good photocatalytic performance and structural tunability. This review summarizes the recent research progress in the field of COFs photocatalytic production of H₂O₂, discussing the reaction mechanisms for the production of H₂O₂ through oxygen reduction, water oxidation, and dual-channel processes. It introduces methods to improve the photocatalytic production of H₂O₂ by regulating the optical bandgap, enhancing charge separation capability, and improving carrier mobility of COFs through structural design and functional group modification. These methods contribute to the design of efficient, stable, and sustainable COFs for photocatalytic production of H₂O₂.

Revealing the intrinsic electronic principles driving the surface chemistry of nanomaterials is a central goal in nanoscience; however, the concepts and theoretical frameworks have long remained incomplete and unsystematic. This review systematically introduces a theoretical framework to reveal the interaction mechanisms and trends of surface ligands with nanomaterials at the electronic level, on the basis of competitive orbital redistribution in chemisorption and a concept of orbital potential, the characteristic electronic attribute directly determining surface reactivity. Based on the competitive interactions between surface coordination bonds and bulk energy bands, this theoretical framework can provide coherent answers to these key scientific issues. (1) The opposite and uniform relation of surface activity and stability in nanomaterials originates from the normalization principle of wavefunctions. (2) The physical nature of enhanced surface activity by size reduction lies in two mechanisms: weakening the constrain strength to surface valence atomic orbitals by nanomaterial energy bands, and amplifying the effects of other structural parameters like defects. (3) Nanoscale cooperative chemisorption (NCC) model generally reveals the electronic-level mechanisms and common rules how ligand coverage regulates the energy band states and physical/chemical properties of nanomaterials. (4) The roles and interaction mechanisms of nanomaterial size (r), specific surface area (S/V), surface ligands, and ligand coverage (θ) in nanomaterial surface chemical reactions are elucidated.

The development of innovative catalysts for various electrochemical scenarios is crucial in satisfying the growing demands for sustainable energy and environmental conservation. Conductive metal-organic frameworks (c-MOFs) based on phthalocyanine complexes known as phthalocyanine-based c-MOFs, have shown promising potential in electrochemical energy conversion and environmental research. These c-MOFs represent a new category of layer-stacked porous MOFs with in-plane extended π-conjugation structure, which can enhance electrocatalytic activity by facilitating the mass diffusion of reactants and electron/charge transfer. The exceptional promising for a variety electrocatalytic reactions, such as water, oxygen, CO₂, and nitrogen conversion. In this work, we focus primarily on phthalocyanine-based c-MOFs rather than other types of c-MOFs, providing a comprehensive overview of their conductive mechanisms and main electrocatalytic reactions. We also cover recent progress in the utilization of phthalocyanine-based c-MOFs as heterogeneous catalysts in electrocatalysis. Furthermore, we explore the challenges related to the utilization of phthalocyanine-based c-MOFs in electrocatalysis. The state-of-the-art research and insights into the future perspectives of phthalocyanine-based c-MOFs as electrocatalysts are also presented and discussed. This work aim to guide the development of phthalocyanine-based c-MOF electrocatalysts with enhanced activity.

Among the many non-precious metal catalysts that have been reported so far, M-N-C catalysts based on transition metal-nitrogen-carbon structure are considered as the most promising candidates to replace Pt-based catalysts for oxygen reduction reaction. Compared with other M-N-C catalysts, Fe-N-C catalysts exhibit the highest ORR activity in acidic environments due to the suitable adsorption energy of oxygen-containing intermediates and thermodynamically favorable 4e pathway. However, the practical application of this catalyst is still limited by the challenge of insufficient stability under the high voltage and strong acidic conditions of PEMFC. Thus, the preparation of stable and efficient Fe-N-C catalysts still faces many challenges. In this review, we systematically summarize the common synthesis methods of Fe-N-C catalysts, including spatial confinement method and template-assisted strategy, outline the half-cell and single-cell test methods used to evaluate the catalyst stability, and analyze the reasons for the discrepancies between the two test results. In order to design highly stable catalysts, a clear knowledge and understanding of the degradation mechanism is required, so we describe four possible degradation mechanisms for Fe-N-C catalysts: demetallization, carbon oxidation, protonation, and microporous water flooding, subsequently we propose some specific strategies to enhance the stability of Fe-N-C catalysts. Finally, the future development direction of Fe-N-C catalysts is discussed in this review. It is hoped that the comprehensive and in-depth study of Fe-N-C catalysts will guide the design and development of highly stable Fe-N-C catalysts for the application of PEMFC.

Atmospheric deposition of desert dust aerosol is a major source of key nutrients for surface seawater in open oceans, significantly impacting marine biogeochemistry and primary productivity. As a tracer for desert dust aerosol, aluminum (Al) is widely used to estimate deposition fluxes of desert dust aerosol into the oceans, and dissolved Al concentrations in surface seawater and aerosol particles are key parameters for using this method to estimate desert dust deposition fluxes into the oceans. In this paper, we first review separation, extraction and detection methods used to measure dissolved Al in seawater and aerosol samples, and discuss their principles, advantages, limitations and applicability. After advances in aerosol Al solubility are systematically reviewed, we point out that the uncertainties in aerosol Al solubility are the bottleneck which currently limits accurate estimations of desert dust deposition fluxes into the oceans, and further analyze the sources of these uncertainties. In the final, we also outline research directions for dissolved Al analysis and aerosol Al solubility research.

Water electrolysis for hydrogen harvesting has become a research hotspot in both academia and industry due to its low carbon emissions, high energy efficiency, and high purity, which offer significant advantages over the majority of hydrogen production technologies. Thereinto, the electrocatalytic hydrogen reaction （HER） is at the core, which aways involves a multi-step hydrogen transfer process and multiple active sites working together. However, catalytic correlations between those active sites and potential hydrogen spillover effects involved are often overlooked. In this paper, we first review the hydrogen evolving properties and reaction mechanisms in electrocatalytic systems such as transition metal oxides, phosphides, and sulfides. By combining traditional theories of thermal catalysis, active sites involved in hydrogen spillover are then conceptually summarized into both the primary and secondary active sites, elucidating their catalytic relevance and functional differences. This paper will not only provide a design concept for the creation of efficient and inexpensive electrocatalysts for hydrogen evolution, but also serve as a useful reference for further studies of hydrogen transfer behaviors in other hydrogen-involved electrocatalytic reactions.

Contents

1 Introduction

2 Electrocatalyst for hydrogen spillover

2.1 Metal oxide

2.2 Metal phosphide

2.3 Metal sulfides

3 Conclusion and outlook

The photoelectric properties of organic luminescent materials with large conjugated structures are closely related to molecular structure and intermolecular interaction. As a basic rigid conjugated unit between large π conjugation and C=X, phenyl has the characteristics of high stability, simple structure and direct relationship between structure and properties, and is the best model compound for studying the excited state properties of obtained luminescent materials. However, phenyl is a liquid at room temperature and becomes a solid at generally harsh low temperatures. Therefore, if the phenyl is fixed in a variety of environmentally responsive skeletons containing heteroatoms, and its condensed state structure and excited state properties will be effectively studied in a wide range, it will solve the important scientific problem of how the phenyl emollients can emit light under different aggregation states. In this paper, the recent advances in the modification of phenyl by heterocycles, conjugation extension of phenyl, substitution of peripheral heteroatoms, bridge between phenyl and other combined strategies are reviewed. The applications of modified phenyl in the synthesis of fluorescent materials, metal-organic complexes or clusters phosphorescent materials, thermally-activated delayed fluorescent materials, aggregation-induced luminescent materials and pure organic room temperature phosphorescent materials were reviewed according to different luminescence mechanisms. Finally, the future research focus and development prospect of organic multifunctional luminescent materials based on modified phenyl are also prospected.

Contents

1 Introduction

2 Fluorescent material based on phenyl derivatives

3 Metal-organic complexes or clusters phosphorescent materials based on phenyl derivatives

4 Thermally activated delayed fluorescence materials based on phenyl derivatives

5 Aggregation-induced emission materials based on phenyl derivatives

6 Pure organic room temperature phosphorescent materials based on phenyl derivatives

7 Organic multifunctional luminescent materials based on phenyl derivatives

Covalent organic frameworks (COFs) are porous organic materials with periodic two-dimensional or three-dimensional network structures consisting of two or more organic molecules connected by covalent bonds. COFs have attracted considerable interest in energy storage due to their beneficial properties, including low skeletal density, high surface area, high porosity, structural designability and functional modifiability. COFs offer unique advantages as positive electrode materials for metal ion batteries due to their rich redox active sites and open framework structure. However, their application in energy storage is limited by challenges such as poor conductivity, low energy density, limited number of available active sites, and blockage of ion transport channels. This article provides a comprehensive review of recent research on COFs as positive electrode materials for metal ion batteries, discussing their types, design strategies, and synthesis methods. Additionally, it presents an overview of the electrochemical energy storage mechanisms from the perspective of different active groups, and the applications of COFs in various metal ion batteries. Finally, it highlights the prospects and challenges of using COFs in energy storage.

With the continuous depletion of fossil energy and the continuous destruction of the ecological environment, developing environmentally friendly renewable electrochemical energy storage devices and biomedical materials is particularly urgent. As an important renewable resource, lignocellulosic biomass has the advantages of low cost, easy accessibility, environmental friendliness, and rich pore structure, and it has a wide range of application prospects as a renewable, biodegradable, and biocompatible substrate for excellent modified materials. The treatment of biomass materials has been from the traditional methods (including combustion, feed, fertilizer and matrix processing), and gradually towards energy, ecology, material modification, and the preparation of new bio-based functional and smart material products, such as: high-performance energy storage devices and biomedical equipment. In short, the development of new matrix and functional materials with biomass as the main raw material is the development trend. In this study, the latest research progress in preparing biomass-derived materials for high-performance energy storage devices and biomedical fields is summarized and overlooked, and the problems and challenges are also pointed out.

Due to the characteristics of large specific surface area, porosity, adjustable structure and easy modification, metal-organic framework materials and their derivatives are widely used as electrode materials, separators, electrocatalysts and other energy storage materials. However, there are still many problems in the practical application of MOFs. This paper reviews the latest developments in the application of MOFs and their derived materials in energy storage devices such as alkali metal ion batteries, metal chalcogenide batteries, aqueous zinc ion batteries, and supercapacitors, and proposes design solutions for problems such as dendrite growth and shuttle effects that often occur in secondary batteries. In addition, the design ideas of MOFs-derived carbon material heterostructure and metal compound structure modification are also summarized. Finally, the intrinsic regulation of MOFs precursors and the modification strategies of derived materials are summarized and prospected.

Representing an important class of ubiquitous chemical feedstock, aromatics have been extensively utilized in the nucleophilic aromatic substitution (S_NAr) reactions, nitration reactions, Friedel-Crafts alkylation and acylation reactions, cross-coupling reactions, C-H bond functionalization reactions etc. Dearomatization reaction is another type of transformations of aromatics, in which their aromaticity is destroyed or reduced. Since its first report, dearomatization reaction has served as an efficient platform to create C(sp³)-H-rich spiro, fused and bridged polycyclic structures, widely applied in material and medicinal chemistry. In the past two decades, various dearomatization reactions have been established by using transition-metal catalysis, organocatalysis, enzymatic catalysis, photocatalysis, and electrocatalysis. Diverse polycyclic structures have been obtained by the dearomatization of indoles, pyrroles, (benzo)furans, (benzo)thiophenes, quinolines, pyridines, benzenes, naphthalenes, etc. The coupling reagents, including nucleophiles, electrophiles, dipoles, radicals, and carbenes have been developed to assemble different functional groups on dearomative framework. In this review, we briefly summarized the developed dearomatization reactions, which were categorized by the kinds of aromatic compounds. The remaining challenges and perspectives on the future development of dearomatization reactions are also included here.

Hydrogen peroxide (H₂O₂) is an important chemical that may be used as a clean disinfectant. For scale application, H₂O₂ is produced primarily by the anthraquinone process. The necessary transportation and storage processes bring explosion risks, so it is urgent to develop in-situ preparation methods. Electrochemical and photocatalytic reduction of oxygen to product H₂O₂ have received wide attention, but these reactions are carried out at the gas-liquid-solid interface. This three-phase reaction requires complex equipment and sequentially limits large-scale production. Another equally important pathway for in-situ H₂O₂ production is the oxidation of water which needs only solid-liquid two-phase interface. This paper summarizes the common methods of oxidizing water to prepare H₂O₂, such as electrochemistry and photocatalysis, and focuses on the recent new methods of in-situ H₂O₂ preparation, including thermal catalysis, ultrasonic piezoelectricity, plasma and microdroplet method. These methods provide the references for in-situ H₂O₂ production and in particular its utilization in the field of disinfection.

Contents

1 Industrial process for the production of hydrogen peroxide

2 In-situ production of hydrogen peroxide via oxygen reduction reaction

3 In-situ production of hydrogen peroxide via water oxidation reaction

3.1 Electrochemical and photocatalytic hydrogen peroxide generation from water oxidation

3.2 Thermocatalytic hydrogen peroxide generation

3.3 Ultrasonic piezoelectrical hydrogen peroxide generation

3.4 Electrical discharge plasma hydrogen peroxide generation

3.5 Generation of hydrogen peroxide from aqueous microdroplets

4 Conclusion and outlook

Lithium-sulfur batteries are valued for their high theoretical specific capacity，energy density，and other advantages，but their commercialization is limited by the slow kinetics of sulfur species conversion and the "shuttle effect". In response，researchers have utilized the photocatalytic effect to develop a photo-assisted strategy for lithium-sulfur batteries，an emerging strategy that not only improves the adsorption and catalytic performance of the catalyst，but also enhances the battery performance in terms of both thermodynamics and kinetics，and even achieves the storage and release of solar energy through the photo-charging mechanism. In this paper，based on recently relevant studies，we introduce in detail the photoelectrochemical principles of photo-assisted lithium-sulfur batteries，discuss the design strategies of photocatalysts and photoanode，as well as the selection of optical windows and encapsulation materials，and review the typical configurations of photopositives and the research methodology of photo-assisted lithium-sulfur batteries，with the aim of attracting the extensive attention of our peers and providing references for the in-depth understanding and improvement of photo-assisted lithium-sulfur batteries.

Contents

1 Introduction

2 The working mechanism and design strategy of photo-assisted lithium-sulfur batteries

2.1 The photoelectrochemical principle of photo-assisted lithium-sulfur batteries

2.2 Design strategies of photo-assisted lithium-sulfur batteries

3 Typical configuration and research methods of photo-assisted lithium sulfur batteries

3.1 Typical configuration of photocathodes

3.2 Research methods for photo-assisted lithium-sulfur batteries

4 Conclusion and outlook

Metal-organic framework compounds (MOF), also known as porous coordination polymers, are a new type of organic-inorganic hybrid porous materials which are self-assembled from organic ligands and metal ions, and are an important part of nanomaterials. Compared to other porous materials, MOFs have a large surface area, high porosity and adjustable structure and properties, making them have a good application prospect in heterogeneous catalysis. In this paper, the background of MOFs catalysis is briefly reviewed, followed by a review and prospect of the recent progress of MOFs in catalytic conversion reactions of organic molecules, in order to provide a reference for the design and development of organic reactions catalyzed by MOFs.

Natural products are secondary metabolites preserved by natural selection in the long-term evolution process of natural organisms, and are widely used in many fields because of their rich medicinal value. With the development of modern science, the demand for high purity products of natural products is also increasing. Traditional separation methods usually have some disadvantages such as large consumption of organic solvents, poor separation effect, high cost and long cycle, which seriously restrict the development and use of natural products in various fields. The emergence of new separation and purification technology provides a new idea for the extraction, separation and application of natural products. On the basis of summarizing the existing literature, this paper reviews the new methods of separation and purification of natural products, and finally summarizes and discusses the research bottleneck and future development direction of natural product separation and purification.

MXene is a two-dimensional transition metal carbon/nitrogen compound or carbon-nitrogen compound obtained from MAX phase materials by chemical etching followed by ultrasonic or intercalation treatment. It has the properties of two-dimensional atomic layer structure, abundant components, metallic conductivity, large specific surface area and active surface, etc. It has distinct infrared absorption in the near-infrared and mid\far-infrared bands, and has attracted extensive attention from researchers in recent years in a number of infrared applications, such as infrared camouflage, photothermal conversion, and photovoltaic effect. In this paper, the properties of MXene materials in the infrared band are reviewed in detail, including the high absorbance and localized surface plasmon resonance effect in the near-infrared band and the infrared low-emission properties in the mid/far-infrared band. Further based on its infrared properties, the research progress of its applications in popular fields such as infrared camouflage, broadband absorber, passive radiant heating, photothermal conversion and photovoltaic effect is summarized. Finally, the main problems of the current research on MXene materials in the infrared field and the future development direction are prospected.

Compared with three-dimensional zeolites, two-dimensional layered zeolites have greater advantages in many fields, with larger surface area, shorter diffusion distance and more ductile structure. In recent years, the research on two-dimensional layered zeolites has become a new hotspot. Based on previous research and summary, this article summarizes the synthesis methods of two-dimensional zeolites in the past five years from two types of synthesis perspectives (bottom-up and top-down methods), with a focus on reviewing the progress of different synthesis methods for the same topology of zeolite. In addition, this article briefly describes the applications of two-dimensional zeolites in the fields of catalysis, adsorption, and separation and looks forward to the broad application prospects of two-dimensional zeolites so as to provide theoretical guidance and reference basis for the synthesis and application of two-dimensional zeolites.

Aliphatic polyesters are important biodegradable polymers and bulk materials, and their monomers of cyclic esters can come from biomass. The catalysts are the key for converting cyclic esters into polyesters, in which the new homogenous catalysts not only initiate the ring-opening polymerization (ROP) of cyclic esters with high activities but also finely tune the molecular weights and structures of the obtained polyesters and thus improve the polymer properties. Currently metal complexes ligated by Schiff-bases have attracted much attention in the ROP of cyclic esters, in contrast,metal complexes containing the phosphorus-nitrogen bond are very limited but display unique catalytic properties and show the potential for industry. The nitrogen and phosphorus possesssimilar electronic structure but with different electronegativity, which helps to adjust the coordination ability of ligand to metal and thus improve thecatalytic performance in the ROP of cyclic esters. The phosphorus-nitrogen bond can be a single bond or a double bond, and the corresponding metal complexes are commonly formed with nitrogen coordination than phosphine coordination, in which by regulating the steric and electronic of phosphine groups the environment around the adjacent coordinatingnitrogen could be adjusted with resulting in good activity but also in controllability to tailor the microstructure of the resultant polyesters. This review collects the recent progress of such multidentate metal complex catalysts containing phosphine nitrogen bond for ring-opening polymerization of cyclic esters, and summarizes the relationship between ligand structure, catalytic performance, and the microstructure of the resulting polyester, which favor the exploring the new efficient complex catalysts and guiding the industry to select the practical catalysts to promote the scientific development as well as industrialization of related technologies.

Contents

1 Introduction

2 Construction methodology of phosphorus nitrogen double bonds (P=N) and single bonds (P—N) in organic compounds

3 Metal complexes containing P-N single bonds for ring-opening polymerization of lactones

3.1 Alkali(alkaline) metal complexes containing P—N single bonds

3.2 Rare earth metal complexes containing P—N single bonds

4 Metal complexes containing P=N double bonds for ring-opening polymerization of lactones

4.1 N^N bidentate metal complexes containing P=N double bonds for ROP

4.2 N^N^X Tridentate metal complexes containing P=N double bonds for ROP

4.3 Ion pair metal complexes with P=N bond for ROP

4.4 N^N^O^O tetradentate metal complexes containing P=N double bonds for ROP

5 Conclusion and outlook

Blue perovskite light-emitting diodes (PeLEDs) restrict the rapid development of full-color display and white lighting technology of perovskite. Quasi-two-dimensional (Q2D) perovskite enables to realize blue light emission via strict control on layer number and use of quantum confinement effect and can significantly improve the stability of perovskite film and PeLEDs by using hydrophobic organic ligands, which has gradually become a research hotspot in the field of perovskites. This review summarizes the research progress on Q2D blue PeLEDs from three aspects of component engineering, film process and device optimization, and analyzes the challenges faced by Q2D blue PeLEDs and the efficiency improvement approaches. At last, this paper envisages the future research direction and feasible solutions.

Contents

1 Introduction

2 Overview of quasi-two-dimensional perovskites

3 Research progress of quasi-two-dimensional blue perovskite light-emitting diodes

3.1 Component engineering

3.2 Film process optimization

3.3 Device structure optimization

4 Challenges faced by quasi-two-dimensional blue light-emitting perovskites

4.1 Photoluminescence quantum efficiency

4.2 Spectral stability

4.3 Phase purity

4.4 Charge injection efficiency and interface engineering

5 Conclusion and outlook

The synthesis of uranium compounds has become one of the hot fields in organometallic chemistry. Compared with transition metal compounds, the synthesis and isolation of uranium compounds is extremely challenging, especially for the ones bearing uranium-carbon bonds. Carbene has lone pair electrons that easily combine with the empty orbitals of uranium. However, the carbon of benzyl or alkyl groups has no lone pair of electrons, which makes it difficult to combine with uranium. With the understanding of the electronic structure and bonding properties of uranium, some progress has been made in the study of uranium compounds coordinated with saturated carbon. This review systematically summarizes the structures and bonding properties of different valence states uranium compounds.

Contents

1 Introduction

2 Trivalent uranium carbon compounds

2.1 Trimethylsilyl based compounds

2.2 Cyclopentadienyl based compounds

2.3 Tripyrazole borate based compounds

3 Tetravalent uranium carbon compounds

3.1 Alkyl based compounds

3.2 Amino and amide based compounds

3.3 Ferrocene based compounds

3.4 Alkoxyl based compounds

4 Pentavalent uranium carbon compounds

5 Hexavalent uranium carbon compounds

6 Theoretical study of U-C bonding nature

7 Conclusion