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.

Theoretical design of fuel has always been the focus of research about fuel in the area of propulsion technology. It can effectively overcome the complexity and potential danger of the experiment, and guide experimental synthesis of fuel, which can be verified by experimental results. It is anticipated that a new generation of fuel can be efficiently designed for subsequent fuel synthesis and application. However, the traditional theoretical calculation methods, such as group contribution method and quantum chemical method, have the defects of low accuracy and efficiency. Machine learning, a rapidly developed algorithm, has opened up a new way to design potential high-energy fuels, which exhibits strong capabilities in both property prediction and molecule design. In this review, several fuel molecule descriptors for machine learning are introduced, and different machine learning models for fuel property prediction and molecule design are briefed. Furthermore, the research on machine learning assisted property prediction and new molecule design of fuel is summarized, respectively. Finally, the challenges and future development of machine learning applied in fuel design are discussed.

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.

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.

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.

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.

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.

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.

Microvasculature-on-a-chip, utilizing microfluidic technology, has emerged as a significant in vitro tool for simulating both the normal and disease states of blood vessel networks. In our review, we highlight the efficacy of microfluidic platforms in accurately reproducing the microenvironment of human blood vessels. We outline a range of methodologies employed to fabricate vascular networks in vitro, focusing on the use of endothelial cells within microfluidic structures. For each method, we provide an assessment of recent examples, critically evaluating their strengths and drawbacks. Furthermore, we delve into the outlook and the innovative advancements anticipated for next-generation vascular-on-a-chip models and the broader field of chip-based tissue engineering.

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.

The design and development of material-microorganism hybrid systems that can use solar energy for green biosynthesis is expected to provide human society with a viable solution for addressing the global energy shortage and environmental crisis. In recent years, the construction of hybrid systems by coupling excellent physical and chemical features of artificial materials with the biosynthetic function of microorganisms has received extensive attention. Polymeric materials, due to versatile functions, excellent designability and good biocompatibility, have been widely used to construct material-microorganism hybrid systems, and have shown broad application prospects in the field of bioenergy. Based on the functional features of polymeric materials, this paper systematically summarizes different types of polymer-microorganism biohybrid systems, and discusses the augmentation of their catalytic performance by enhancing light utilization, accelerating electron transfer, and stabilizing biological activity. Finally, the challenges and future development of polymer-microorganism hybrid systems are discussed.

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 portable electronic products and electric vehicles, the demand for high energy density lithium-ion batteries is increasing. High-nickel ternary materials with nickel content higher than 0.6 (include) (e.g., LiNi_0.6Co_0.2Mn_0.2O₂, LiNi_0.8Co_0.1Mn_0.1O₂ and LiNi_0.9Co_0.05Mn_0.05O₂), which can deliver a high reversible specific capacity of more than 200 mAh·g^-1 at an upper cut-off voltage of 4.3 V vs Li⁺/Li, are an important development direction of cathode material with high specific capacity. However, the weak mechanical strength, low compaction density of polycrystal ternary materials and the anisotropy of primary grains lead to intergranular cracks in the polycrystal particles during the charging and discharging process. The electrolyte will penetrate into the polycrystal particles along the intergranular cracks, thus aggravating the side reaction between the electrode and electrolyte and deteriorating the cycle performance and safety of the battery. The design of single crystal material without grain boundary can reduce the formation of intergranular cracks, effectively suppress the side reaction at the interfaces and improve the cycle stability. In this study, the advantages and problems of single-crystal high-nickel ternary materials are reviewed, and their synthesis methods and modification strategies are analyzed. Finally, the application prospects and challenges of single-crystal high-nickel ternary materials are reviewed and prospected.

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.

Hydrogel materials are widely used due to their excellent hydrophilicity, biocompatibility, adjustable biomimetic properties, etc. However, their inherent non-uniform microstructure and low-density molecular chains make their mechanical properties poor, which limits their practical applications. The preparation of hydrogel materials with high mechanical strength yet toughness has been a challenge for research in this field. As composites are constantly developing in the direction of functionalization and intelligence, the introduction of polymer hydrogels into the textile field for the preparation of gel-based textile composites not only improves the defects of gel materials, but also gives textiles excellent properties and broadens their potential application prospects. This paper reviews the research progress of hydrogel textile composites, focusing on the design strategy of hydrogel-based textile composites and their enhanced mechanical and antimicrobial properties, discusses the application progress of the composites in the fields of oil-water separation, medical dressings, wearable electronic devices, and flame-retardant protection, and the future research direction is also prospected.

Quantum dots are considered as ideal luminescent materials for high color gamut, flexible, and large area display, medical devices, and the application of other fields, due to their unique photoelectric properties. Compared with the quantum dots of binary Ⅱ-Ⅵ or Ⅲ-Ⅴ group, the quantum dots of ternaryⅠ-Ⅲ-Ⅵ₂ group have significant advantages in terms of ecological and environmental friendliness without containing Cd or Pb elements, large Stokes shift with adjustable band gap, long-life luminescence, etc. Moreover, it is facile to obtain emission wavelength adjustable continuously from visible to near-infrared region by changing chemical elements ratio in the composition of single Ⅰ-Ⅲ-Ⅵ₂ family. These characters make the Ⅰ-Ⅲ-Ⅵ₂ quantum dots have broad application prospects in the fields of light-emitting diodes, solar cells, photodetectors, biological imaging, etc. This paper systematically reviews the synthesis methods and optical performance optimization strategies of quantum dots and those suitable for I-III-VI₂ quantum dots, explains the luminescence mechanisms of I-III-VI₂ quantum dots based on their electronic band structures, summarizes recent-years progress of quantum dots application in lighting and display devices, and focuses on the application progress of the I-III-VI₂ quantum dots in photo- and electroluminescent diodes. Finally, the future prospects and challenges of I-III-VI₂ quantum dots are prospected.

Combination products present significant opportunities for advancing traditional medical devices by versatile integration of therapeutic drugs and devices. As clinical needs evolve, there remains growing interest in developing new surface and interface engineering technologies for modulating drug delivery behavior. Recently, polymeric porous surface interface technology has emerged as a robust strategy for the flexible amalgamation of functional molecules with medical devices via capillary adsorption. In comparison to the conventional coating method, this technology shows distinctive features like flexible loading, facile dosage control, and tunable release, therefore providing a novel insight for personalized medicine. This review begins by outlining the methods for preparing porous surfaces of polymer materials, including the breath figure, template method, surface non-solvent-induced phase separation, stimulus-induced phase separation method, and electrospinning method. Then, the mechanism for the capillary-based loading process and hindered release behavior of functional species, which play a central role in the development of spongy surface-based combination devices, is discussed. This review also provides an overview of the latest research on the porous surface interfaces of polymer materials in applications like targeted anti-cancer, cardiovascular implants, and bone repair, summarizes the present challenges in research on the porous surfaces of polymer materials, and highlights insights into potential future directions.

Sludge is an inevitable by-product of the wastewater treatment process and due to its high water content, large volume, and inclusion of a large amount of toxic and hazardous substances, needs to be minimized and harmlessly treated. However, sludge possesses extracellular polymeric substances (EPS) formed by ionization of negatively charged functional groups, which maintain a stable hydrated colloidal structure and prevent the release of water. This is a key factor in the difficulty of sludge dewatering. In the last decade, sulfate radical-based advanced oxidation processes (SR-AOPs) have received considerable attention due to their high efficiency for EPS disintegration, rapid reaction time and environmental friendliness, and thus sulfate radicals have become a new powerful tool for enhancing sludge dewaterability. In this paper, the development timeline and activation mechanisms of sulfate radicals are reviewed in detail, and the research advances of SR-AOPs for improving sludge dewaterability and removing micropollutants and heavy metals from sludge are systematically evaluated. Based on the current scientific problems of SR-AOPs in sludge conditioning, the future research directions of SR-AOPs are proposed from the perspectives of mechanism research, cost-effectiveness, and experimental scale, in order to provide a solid theoretical reference for sludge conditioning in wastewater treatment plants in China.

The problem of excess glycerol as a by-product of biodiesel production has become more and more prominent, and the catalytic conversion of glycerol to high-value-added chemicals is of great significance. In recent years, noble metal catalysts (Au, Pt, Pd, etc.) are often used to catalyze the conversion of glycerol to lactic acid, in which the improvement of lactic acid selectivity and catalyst stability are the key challenges for the catalysts. Here, we summarized the reaction mechanism of selective oxidation of glycerol to lactic acid over supported noble metal catalysts, revealing the role of different metal active sites. At the same time, the effects of metal particle size, support, and pH of the reaction system on the reaction performance are discussed based on the structure and electronic properties of noble metal active sites. Also, the role of metal in the promotion and support of strong interaction on the activation of the hydroxyl groups of glycerol was clarified. Finally, the main challenges and prospects for the selective oxidation of glycerol to lactic acid were clarified.

Oxide aerogel is one type of three-dimensional nano porous material, which has the advantages of high porosity, high specific surface area, low thermal conductivity, high melting point and so on. Moreover, oxide aerogel always shows excellent high-temperature resistance and thermal insulation performance. Thus, in this paper,the research progress of heat-resistant oxide aerogels including silica, alumina, zirconia aerogels, binary and multi-component and their composite counterparts are reviewed. The preparation method and performance of oxide aerogels are summarized, the existing problems are pointed out, and the application of oxide aerogels in the field of high temperature thermal insulation is prospected.

Contents

1 Introduction

2 Preparation of oxide aerogel

2.1 Preparation method

2.2 Drying method

3 SiO₂ aerogel

3.1 Precursor of SiO₂ aerogel

3.2 Pretreatment of SiO₂ aerogel

3.3 SiO₂ composite aerogel

4 Al₂O₃ aerogel

4.1 Precursor of Al₂O₃ aerogel

4.2 Structural control of Al₂O₃ aerogels

4.3 Al₂O₃ composite aerogel

5 ZrO₂ aerogel

5.1 Precursor of ZrO₂ aerogel

5.2 Structural control ZrO₂ aerogels

5.3 ZrO₂ composite aerogel

6 Two component and multi-component oxide aerogel

6.1 Two component oxide aerogel

6.2 Multi-component oxide aerogel

7 Conclusion and outlook