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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

Plastic products represented by polyethylene terephthalate (PET) have become an important part of modern life and global economy. In order to solve the resource waste and environmental problems caused by PET waste and to realize high-value recycling of materials, there is an urgent need to explore low-cost green and efficient conversion and recycling methods. Chemical depolymerization can deal with low-value, mixed, and contaminated plastics, recover polymer monomers through different chemical reactions or chemically upgrade and recycle to produce new high value-added products, realizing the closed-loop recycling of plastic waste and high value-added applications, which is a key way to establish a circular polymer economy. This paper reviews the latest research progress of chemical depolymerization process of PET waste, analyzes the problems of chemical depolymerization technology of PET waste, and looks forward to the future development trend of chemical depolymerization process of PET waste.

With the rapid development of social economy and the continuous improvement of people's living standards, medical and health care have taken on an important strategic position. As an important analytical detection method, biosensing technology plays a key role in the field of medical health. Piezoelectric biosensor, as a new kind of biosensor, utilizes piezoelectric materials for biological analysis. Piezoelectric biosensor has the advantages of good stability, fast detection speed, high accuracy and simple operation, and has important application value in biomedicine, health monitoring and disease prevention and control. Herein, we review the research progress of piezoelectric biosensor home and abroad in recent years, and introduce the principle of piezoelectric biosensors based on the piezoelectric effect of quartz crystal microbalance and the commonly used piezoelectric materials, including inorganic piezoelectric materials, organic piezoelectric materials, piezoelectric composite materials and biological piezoelectric materials. In addition, the applications of piezoelectric biosensors in human health monitoring and disease prevention and control are also introduced, such as the monitoring of physiological signs, such as heart rate, blood pressure and pulse, the detection of biomarkers and epidemic viruses such as SARS-CoV-2 (COVID-19). Finally, the current problems faced by piezoelectric biosensors are summarized, and the future development of piezoelectric biosensors is prospected.

Nowadays stretchable electronic devices have become a hot research topic in the field of information electronics because of their excellent mechanical and electrical properties. As the high-speed electron transmission channel in stretching electronic devices， stretchable conductive materials play a crucial role in realizing the functions of stretching electronic devices. Liquid metal has become a hot research object in the field of stretchable conductive composites in recent years because of its intrinsic flexibility and excellent conductivity. Liquid metal is a room temperature liquid conductive material， which exhibits excellent stretchability and tunability due to its inherent high conductivity， fluidity， and ductility. Liquid metal-based stretchable conductive composites preparation and patterning techniques have been reported and many stretchable devices with excellent combination of mechanical and electrical properties have been prepared. In view of the general structural characteristics of liquid metal-based stretchable composites， the key to the preparation is how to solve the interfacial non-impregnation problem caused by the physical property differences between different materials. Therefore， starting from the common types of composites， this paper firstly briefly introduces the components and physical properties of liquid metals generally used， as well as the stretchable polymer matrix materials usually employed. Then， the composite methods of conductive materials and elastomer materials in liquid metal-based electrodes are reviewed from the two ways of "passive" and "active" to deal with the problem of non-wetting at the interface， as well as the blending and dispersion method and the new modification method. Finally， the latest research progress is introduced， and the current status of liquid metal research is summarized. Future development and potential problems to be faced are also discussed.

During many life processes such as replication, transcription, double-strand breaks repair and so on, double-stranded DNA will temporarily unwind and form single strand DNA (ssDNA). ssDNA may affect genomic stability and may also participate in the formation of non-B DNA structure, which in turn regulates and influences many key cellular processes. This review briefly describes the causes of the formation of single-stranded DNA, the structures containing single-stranded DNA and their possible functions in cells, and summarizes some high-throughput analysis techniques of single-stranded DNA, which provides the method inspiration for the subsequent ssDNA research and promotes the further development of ssDNA analysis techniques and methods.

To take advantage of renewable energy such as solar energy to split water to hydrogen is an important solution to address the environmental pollution and energy shortage crisis. The development of highly efficient, robust, and low-cost catalysts is the key to the production of green and clean hydrogen energy. Transition metal phosphides (TMPs), as kinds of composites that can replace noble metal catalysts, have attracted wide attention in the field of solar hydrogen production. However, the poor stability of TMPs under harsh reaction condition limits their large-scale application at industrial level. In this paper, the physicochemical properties, preparation methods, stability in catalytic reactions and stability improvement strategies of TMPs are reviewed. The reason for the decline of stability of TMPs is that they could react with H₂O or O₂, and TMPs are oxidized to metal oxides or hydroxides, Meanwhile the low valence phosphorus is oxidized to phosphate and dissolved in the reaction medium, resulting in the loss of phosphorus in TMPs. The stability of TMPs could be improved by means of tuning the polarity of support surface, coating protective layer, and doping foreign elements.

The rapid development of infrared detection equipment has caused a huge threat to military equipment. And infrared stealth technology is an important way to improve the survival, strike and breakthrough capabilities of military equipment, and plays a vital role in the development of the national defense industry. However, the battlefield environment is complex and changeable, and materials with only infrared stealth performance are difficult to meet the actual needs when facing radar detection, rainforest, mountain, ocean, desert and other environments. Therefore, it is imperative to develop multifunctional infrared stealth materials. In this paper, the latest research progress of different infrared stealth materials is reviewed from the perspective of the mechanism of infrared stealth materials, such as low emissivity materials, temperature control materials, variable emissivity materials and cooperative working mode materials, and the control methods of different infrared stealth materials are discussed. Secondly, the multi-functional infrared stealth materials suitable for different application scenarios, such as multi-band stealth, electromagnetic shielding, antibacterial and waterproof, high temperature resistance, anti-corrosion and flame retardant infrared stealth materials, and their design mechanisms are discussed. Finally, the future development of multifunctional infrared stealth materials is summarized and prospected.

With the development of science and technology, nuclear technology is widely used in energy, medicine, aerospace, and other fields. However, the high-energy gamma ray produced by the application of nuclear technology has strong penetrating ability and can ionize human cells, which will cause damage to human health. Therefore, it is crucial to develop effective radiation shielding materials. Since the density and effective atomic number of materials have great influence on the gamma shielding properties of materials, fillers containing high atomic number (high Z) elements are introduced into various matrix materials by researchers to prepare composite shielding materials. This paper explains three fundamental physical effects of the interaction between gamma photons and atoms. Three kinds of high Z gamma ray composite shielding materials based on glass, polymer, and metal matrixes are introduced respectively, and the existing challenges and solutions are summarized.

Nucleic acid hydrogels have good hydrophilicity, adjustability and biocompatibility, which have attracted considerable attention in the past few years, especially in the field of biomedicine and smart materials. Nucleic acid hydrogel is stimulus-responsive, meaning that external stimuli such as pH changes, light, temperature variations, and chemical triggers (including metal ion response, redox response, and enzyme response) can induce physical and chemical changes within them. Consequently, they are capable of perceiving their environment and undergoing responsive deformation, enabling precise cell therapy that can be controlled both temporally and spatially. Cell capture and release using stimulus-responsive nucleic acid hydrogels can control and modulate cellular behavior, and can also play an important role in biomedical research and applications, such as targeted drug therapies using the capture and release of specific cell types. Based on this, this paper summarizes the preparation methods of pure nucleic acid hydrogels and polymer-nucleic acid hybrid hydrogels, further discusses the application strategies of different stimuli-responsive nucleic acid hydrogels, and focuses on the research progress of cell capture and release in cell imaging, cell therapy and synergistic drug delivery. Finally, we discuss the urgent problems that need to be addressed in the research of nucleic acid hydrogels, and provide a prospect for their future development.

Contents

1 Introduction

2 Preparation of nucleic acid hydrogels

2.1 Pure nucleic acid hydrogel

2.2 Polymer-nucleic acid hybrid hydrogel

3 Stimulus-responsive nucleic acid hydrogels

3.1 pH response

3.2 Light response

3.3 Temperature response

3.4 Chemical trigger

4 Stimulus-responsive nucleic acid hydrogels used for cell capture and release

4.1 Cell imaging

4.2 Cell therapy

4.3 Collaborative drug delivery

5 Conclusion and outlook

Photoelectrochemical sensing analysis is a rapidly developing new analytical technology in recent years, and photoelectric active materials are the key to photoelectrochemical sensing detection. Metal-organic frameworks (MOFs) and their derivatives may be ideal carriers for the construction of photoelectrochemical sensing interfaces by dispersing photoelectrically active substances. Due to the "antenna effect" of organic ligands in MOFs, the metal clusters can be regarded as activated discrete semiconductor quantum dots, giving them photoelectric properties similar to those of semiconductors. The modification of MOFs materials with carbon-based compounds, organic polymers, noble metal nanoparticles, inorganic oxides, and quantum dots, and the construction of MOFs-based photoelectrochemical sensing interfaces, can improve the electrical conductivity of MOFs, promote the separation of photogenerated electrons-holes, and thus improve the photoelectric conversion efficiency. The MOFs-based photoelectrochemical sensing interfaces amplify the signal generated by photoelectrochemical sensing, enabling ultra-sensitive detection of the target object. Based on these, this study provides a detailed introduction to the photoelectric activity mechanism, synthesis methods, and strategies for constructing photoelectric activity interfaces of MOFs-based materials. The applications of MOFs-based materials in photoelectrochemical sensing detection of small molecule compounds, immunoassay, enzyme activity and environmental analysis in recent years have been comprehensively reviewed. Finally, current challenges and future perspectives in this field are also proposed.