For halogenated organic compounds, antibiotics, and other emerging contaminants that are persistent and highly toxic, micro-electrolysis fillers can effectively disrupt the chemical structures of these contaminant molecules and achieve the effect of deep mineralization through direct electron reduction and electrochemical oxidation. However, although the traditional micro-electrolysis process has achieved certain results, there are still many thorny problems. For example, the stability of the fillers is poor, their service life is short, and they are prone to caking and passivation, which leads to clogging of the reactor, requiring frequent replacement of the fillers. To overcome these problems, granulation is usually employed to increase the interfacial bonding strength between iron powder and activated carbon powder. However, previous studies have often focused on the influence of the composition or preparation methods of the fillers on their performance, while the role of the binders has been subtle and difficult to detect. Through in-depth investigations, it has been found that binders play a key role as the 'unsung heroes' in enhancing the performance of micro-electrolysis fillers and that their functional groups and chemical structures have a profound effect on the performance of the fillers. They can not only strengthen the mechanical strength of fillers, improve their stability and anti-passivation ability, promote the mass transfer process, prevent filler caking, and prolong the service life of fillers, but also increase the utilization rate of electrons and catalyze the occurrence of reactions, thereby further enhancing the degradation activity of emerging pollutants. Given this, this paper systematically summarizes the interfacial bonding mechanisms of commonly used binders in different granulation methods, analyses the deep action mechanisms of binders in enhancing the performance of micro-electrolysis fillers, discusses the influence laws of binder types and contents on the fillers, and looks forward to the development of new fillers, and looks forward to the development of new high-performance binder materials, the optimizing of the process parameters of binders in the filler preparation process, and the in-depth exploration of the action mechanisms between binders and active components of fillers, with the expectation of promoting the development of micro-electrolysis fillers in the field of environmental management.

Contents：

1 Introduction

2 Interfacial bonding mechanism during granula-tion of commonly used binders

2.1 Inorganic binder

2.2 Organic binder

2.3 Composite binder

2.4 Comparison of the performance of binders

3 The main methods of binder granulation

3.1 Sintering

3.2 Carbothermal reduction

3.3 Gelation

3.4 Liquid phase reduction

3.5 Burden

3.6 Comparison of granulation methods

4 Extended life cycle

4.1 Optimization of filler mechanical strength

4.2 Improved filler stability

5 Enhanced electronic utilization

5.1 Broadening the path of e-transfer

5.2 Modulation of electron transfer

6 Improvement of reaction efficiency

6.1 Catalytic activation

6.2 Promotion of micro-electrolysis

6.3 Adsorption and flocculation

7 Factors affecting binder granulation

7.1 Types of binders

7.2 Content of binders

8 Conclusion and outlook

Sweet-tasting proteins, characterized by their low calorie and high sweetness attributes, demonstrate significant potential in the food industry. They not only satisfy the demand of consumers for healthy and safe sweeteners but also have the potential to replace traditional high-calorie sweeteners, thus driving innovation in the food industry. However, their commercialization process still faces challenges such as restrictions on the origin of raw materials, low yield, high extraction costs, and poor stability. In this review, the basic characteristics of sweet-tasting proteins were examined, their taste mechanisms and the relationship between their structure and sweet taste activity were investigated. Precise design and modification of sweet-tasting proteins and host through synthetic biology and artificial intelligence methods to enhance their sweetness, stability and yield were proposed. Additionally, optimizing host, expression and secretion strategies, as well as precise control of the fermentation process, can further improve the yield and activity of sweet-tasting proteins. These approaches provide a theoretical basis and technical references for addressing the existing problems in the commercial application of sweet-tasting proteins and have positive implications for promoting their widespread use in the food industry.

Contents

1 Introduction

2 Taste mechanism and structure-function relationship

2.1 Recognition and signal transduction of sweet taste receptors

2.2 Structure-function relationship analysis

3 Customized optimization and production strategies

3.1 Protein precision design and modification

3.2 Optimization of strategies for host cell selection

3.3 Optimization of expression and secretion strategies

3.4 Precise control and optimization of the fermentation process

4 Conclusion and outlook

Chemical looping (CL) technology has been widely used in fields such as in-situ capture of carbon dioxide, hydrogen production, oxidative dehydrogenation and partial oxidation of methane. The development of oxygen carriers is the key link to the advancement of CL. Exploring the mechanism of oxygen storage and release in the oxygen carrier lattice is important for the design of high-performance oxygen carriers, the explanation of CL reaction mechanism, and the regulation of product selectivity and yield. First, this paper systematically reviews the research methods and progress of oxygen storage and release mechanism of oxygen carriers, presenting the important role of key characterization techniques in exploring the lattice oxygen migration mechanism. At the same time, we summarize the reaction mechanism of different types of oxygen carriers and the spatiotemporal evolution characteristics of active components, providing theoretical support for the design and modification of oxygen carriers. Furthermore, this paper also focuses on the difficulties and controversies in the study of oxygen storage and release mechanism of CL oxygen carriers. Finally, some perspectives on the current studies of mechanism for oxygen carriers were presented.

Contents

1 Introduction

2 The research method to study the mechanism of oxygen storage and release by oxygen carriers

2.1 Advanced characterization Techniques

2.2 Experimental design method

2.3 Primary calculation method

3 Study on lattice oxygen migration mechanism during oxygen storage and release

3.1 Lattice oxygen migration mechanism of spinel oxygen carriers

3.2 Lattice oxygen migration mechanism of perovskite-type oxygen carriers

3.3 Lattice oxygen migration mechanism of other metal based oxygen carriers

4 Study on metal ions migration mechanism during oxygen storage and release

5 Research limitations in oxygen storage and release processes

5.1 Limitations of the research method

5.2 Limitations of the research mechanism

6 Conclusions and outlook

Iron cobalt phosphide is considered to be an important candidate material for anodic water dissociation due to its low cost and high catalytic activity, but it still suffers from poor intrinsic conductivity and limited active sites. Starting from the anodic hydro-electric oxidation process represented by oxygen evolution reaction, we systematically reviewed the research progress of adjusting electronic structure, optimizing adsorption energy of water oxidation intermediates, and improving stability for iron cobalt phosphide based materials through strategies such as intrinsic activity regulation, doping engineering, defect design, and heterogeneous structure construction. Finally, the development of iron cobalt phosphide based anode materials is prospected.

Contents

1 Introduction

2 Water oxidation process

3 Strategies for improving the water dissociation performance of FeCoP based anode materials

3.1 Intrinsic activity regulation

3.2 Doping engineering

3.3 Defects design

3.4 Heterojunction engineering

Chemodynamic therapy (CDT) refers to a method that utilizes metal ion-mediated Fenton/Fenton-like reactions to catalyze the generation of highly cytotoxic hydroxyl radicals from hydrogen peroxide, effectively killing tumor cells. It offers advantages such as tumor specificity, minimal side effects, and a treatment process initiated solely by internal tumor substances like H₂O₂ and glutathione without the need for external stimuli. However, the high concentration of glutathione in the tumor microenvironment, insufficient endogenous hydrogen peroxide, and hypoxia hinder the therapeutic effect of CDT. To enhance its effectiveness, researchers have explored various metal ion-mediated Fenton/Fenton-like reactions, leading to the proposed combination of CDT with multiple other therapies. This article reviews the reaction mechanisms of CDT and its collaborative applications with various therapies in anti-tumor treatment. It begins by discussing the catalytic reaction mechanisms of CDT mediated by different metal ions, delving into the advantages and disadvantages of various ions in catalyzing Fenton or Fenton-like reactions. Subsequently, it details the latest research progress on the combination of CDT with other therapies, such as photothermal therapy, chemotherapy, and photodynamic therapy, in anti-tumor treatments. Finally, the article proposes future research directions for the development of chemodynamic therapy and highlights key issues that need to be considered to further promote its clinical research applications.

Contents

1 Introduction

2 Mechanism for Fenton reaction mediated by various metal ions

2.1 Iron-mediated mechanism for Fenton reaction

2.2 Copper-mediated mechanism for Fenton-like reaction

2.3 Other metal ion-mediated mechanisms for Fenton-like reactions

3 CDT-based combination therapies and their anti-tumor applications

3.1 Combination therapy of PTT and CDT

3.2 Combination therapy of chemotherapy and CDT

3.3 Combination therapy of PDT and CDT

3.4 Combination therapy of other therapies and CDT

4 Conclusion and perspective

Bone defects caused by accidents or diseases are a common and serious problem in orthopedic surgery. Finding ideal bone repair materials has become a hotspot in current bone tissue engineering. Polyurethane (PU) is a multiblock copolymer with a microphase-separated structure formed by alternating soft and hard segments. Its application properties - such as mechanical performance, biocompatibility, and biodegradability - can be tailored by adjusting the soft segment structure, hard segment ratio, crystallinity, and other factors, demonstrating broad prospects in the field of bone defect repair. This paper reviews recent research on the design, synthesis, modification, and biological performance of PU in bone tissue engineering, with a focus on its application progress in bone regeneration, including implantable scaffolds, injectable materials, and drug carriers. The aim is to provide more insights for the future design and clinical application of PU materials.

Contents

1 Introduction

2 Development of polyurethane

3 Synthesis of polyurethane

3.1 Main raw material

3.2 Main reaction pathways

4 Structure of polyurethane

5 Properties of polyurethane

5.1 Mechanical properties

5.2 Biological activity

5.3 Biodegradation

5.4 Shape memory properties

6 Applications of polyurethane in bone defects repairing

6.1 Implanted scaffold

6.2 Injected polyurethane

6.3 Drug carrier

7 Conclusion and outlook

Metal-organic frameworks (MOFs) exhibit great promise in diverse applications such as gas storage, catalysis, and sensing due to their distinctive structures and physicochemical properties. However, traditional experimental approaches face challenges in quickly and efficiently designing MOFs with the desired characteristics. In recent years, artificial intelligence (AI) techniques, particularly traditional machine learning and deep learning, have been extensively applied in materials science, yielding numerous noteworthy results. An essential requirement for successful modeling with these techniques is the ability to extract the structural features of MOFs and transform them into computer-readable formats. Therefore, we present a comprehensive review of two feature extraction approaches based on molecular descriptors and end-to-end deep learning. We summarize the fundamental concepts and principles of both methods, emphasizing their specific applications and recent advancements in MOFs design. Finally, we discuss the challenges and future directions for improving the comprehensiveness, interpretability, and reproducibility of structural feature extraction. This review aims to provide valuable insights and theoretical guidance for AI-driven MOFs design.

Contents

1 Introduction

2 Traditional machine learning and end-to-end deep learning

2.1 Basic concepts and historical development of artificial intelligence

2.2 Key steps in traditional machine learning and end-to-end deep Learning

2.3 Differences between traditional machine learning and end-to-end deep Learning

2.4 Overview of the MOF databases

3 Feature extraction based on molecular descriptors

3.1 Structural descriptors

3.2 Chemical characteristics

3.3 Thermodynamic properties

3.4 Feature selection and dimensionality reduction techniques

3.5 Effective strategies for handling missing features and noisy data

4 Application of end-to-end deep learning model to MOFs design

4.1 Convolutional neural networks

4.2 Recurrent neural networks

4.3 Graph neural networks

4.4 Generative adversarial networks

5 Challenges and prospects

Covalent organic frameworks (COFs), as a new class of functional organic materials, have attracted extensive at-tention since they were first proposed in 2005. In recent years, the application in biology is particularly prominent. Porphyrin-based COFs exhibit excellent advantages, such as high crystallinity, high porosity, flexible design, easy to surface modification and so on. These remarkable features enable them to serve as carriers of various therapeutic agents for drug delivery. Due to their special structure, such as the extended conjugate structure and the strong π-π packing interaction, porphyrin-based COFs exhibit a strong absorption effect in the visible region, have excellent thermal stability and chemical stability. In addition, they can be used as photosensitizers, so they have wide appli-cation potential in tumor therapy. This article focuses on the research progress of monotherapy and combination therapy based on porphyrin-based COFs for tumor. Finally, the challenges and prospects of their preparation and application in tumor therapy are discussed.

A unidirectional moisture transport material is a specialized type of material designed to transport moisture from one side to the other while simultaneously preventing moisture from moving in the opposite direction. Among these innovative materials, pore-gradient unidirectional moisture transport materials stand out as particularly significant. These advanced materials achieve unidirectional water transport through a carefully engineered gradient of pore sizes within the material, a process driven by the Laplace pressure. Such materials are not only eco-friendly and stable but also operate without requiring any external energy input, making them highly applicable and valuable in fields such as directional water collection, liquid transport, and oil-water separation. This paper first introduces a detailed classification of the various unidirectional moisture transport mechanisms and explains the underlying theoretical mechanisms from an energy perspective. It then reviews and analyzes the different types of pore-gradient materials. Finally, the paper discusses both the current and future applications of unidirectional moisture transport materials, along with a comprehensive analysis of their limitations and potential development directions.

The covalent organic framework colloid (COF Colloids) embodies not only the inherent traits of a controllable COF structure, adjustable pore size, and ordered crystalline structure, but also capitalizes on the versatility inherent in colloids for dispersion, molding, functionalization and assembly. In recent years, COF colloids have garnered substantial interest among researchers owing to their exceptional solution processability and stability. This paper delves into the formation mechanism of COF colloids, categorizing their preparation methods into two classifications: top-down and bottom-up. It also provides a comparative analysis of the advantages and limitations associated with these two synthesis strategies. Moreover, this review summarize the diverse applications of COF colloids in photocatalysis, devices, gas separation, and biomedicine, while also addressing the challenges by COF colloids and envisioning their future developmental trajectory.

PET-RAFT polymerization (Photoinduced Electron Transfer-Reversible Addition-Fragmentation Chain Transfer Polymerization) has been widely concerned and applied in the field of polymerization due to its characteristics such as low energy consumption, mild reaction conditions, time-space control, reaction orthogonality and oxygen resistance. In terms of surface modification, PET-RAFT polymerization is used to improve the surface characteristics of materials, such as biocompatibility and anti-adhesion. In the biomedical field, PET-RAFT polymerization technology is used to prepare drug delivery systems such as spherical micelles and vesicles. In addition, the application of PET-RAFT polymerization in 3D printing and laser writing demonstrates its great potential for precise control of material structure and functionalization. The key to PET-RAFT polymerization is to find suitable photocatalysts. Currently, the types of catalysts include homogeneous catalyst systems, such as transition metal complexes, porphyrin and phthalocyanine catalysts, organic dyes, and semiconductor materials, as well as heterogeneous catalyst systems, such as macro material supported, nano material supported, metal organic framework, co valent organic framework, conjugated microporous polymers, etc. Among them, heterogeneous catalysts can be effectively recovered and utilized by centrifugation and filtration separation of photocatalysts.The heterogeneous catalyst can be effectively recycled by centrifugation and filtration separation. In the future, researchers will develop new low cost, high efficiency, easy recovery, non-toxic photocatalysts to improve the use of low energy photons and improve the compatibility of photopolymerization with the environment.

With the continuous improvement of environmental monitoring requirements, the application of new materials has attracted much attention. Covalent organic framework (COFs) materials have a series of remarkable advantages, such as structural design, large specific surface area, high porosity and good chemical stability, and show great potential in the key field of environmental monitoring. This paper focuses on the analysis and application of COFs materials in the field of environmental monitoring. The unique advantages of COFs in the treatment and detection of heavy metal ions, organic pollutants and gas pollutants are described in detail, and the application examples and effects of COFS combined with modern analysis and detection techniques and tools are analyzed. It can make full use of its structural characteristics to achieve high efficiency enrichment or adsorption of target pollutants in complex environmental samples, so as to simplify the accurate detection process of modern analytical instruments such as high performance liquid chromatography, gas chromatography, mass spectrometry, and improve the detection sensitivity and reduce the detection limit. In addition, the application examples and effectiveness of these analytical tools, such as electrochemical sensors, fluorescence sensors, indicator enhanced Raman spectroscopy, colorimetry and gas sensors, in the detection of common environmental pollutants are also discussed. At the same time, some limitations of COFs materials in practical applications are also clearly pointed out. Finally, the future development direction and prospect are prospected, and some thoughts and suggestions are provided for its further development in the field of environmental detection.

With the continuous advancements in materials science and membrane separation technology, two-dimensional (2D) materials have demonstrated significant potential in the fabrication of novel separation membranes. The ultra-thin thickness of 2D materials facilitates the reduction of mass transfer resistance, thereby enhancing permeability. Moreover, the in-plane or interlayer channels of 2D materials can be engineered to precise dimensions for accurate size sieving. When utilized in separation membranes, these characteristics enable simultaneously high mass transfer efficiency and separation capability. This review introduces various 2D materials suitable for separation membrane fabrication and outlines three primary membrane preparation strategies. The resultant membranes exhibit excellent performance in water treatment, organic solvent separation, and gas separation. The formation of pores in 2D material-based mem-branes, which includes interlayer and in-plane mass transfer channels, is discussed as a critical factor in membrane performance. Finally, the paper summarizes current challenges and research hotspots in this field, while outlining key research directions for the near future.

In recent years, novel 2D materials such as MXene have demonstrated considerable promise for thermoelectric applications, owing to their excellent conductivity, excellent mechanical flexibility, and good environmental stability. However, the metallic behaviour exhibited by the charge carrier transport of MXene hinders the Seebeck effect, thus limiting effect of the strong coupling between the Seebeck coefficient and the conductivity. Due to their special electrical, thermal, and structural properties at the micro/nano scale, low-dimensional materials are expected to be compounded with MXene and their thermoelectric properties can be regulated. In this review, we summarize the research progress of MXene and other low-dimensional materials to improve its thermoelectric properties, focusing on the combination of one-dimensional materials, two-dimensional materials and MXene. We then proceed to optimise the key thermoelectric performance indicators including conductivity, thermal conductivity, and the Seebeck coefficient. The subsequent research direction of the thermoelectric properties of MXene materials is proposed, and this is based on three aspects: optimization of material synthesis technology, material design combined with artificial intelligence, and application of flexible wearable electronic devices.

Compared with short-lived radicals, environmentally persistent free radicals (EPFRs) can exist in the environment for a long time and have long-distance migration ability. They mainly derive from vehicle emissions, industry emissions and biomass combustion. They are usually generated on the surface of particles. EPFRs exist widely in various environmental media like atmospheric particulate matters (PMs). Because the composition, source and formation mechanism of PMs varies in different regions, different seasons and different particle sizes, the characteristics of EPFRs are also different. Electron Paramagnetic Resonance (EPR) is an effective method to determine EPFRs in PMs. EPFRs on PMs can induce reactive oxygen species (ROS), cause oxidative stress in the cell and oxidative DNA damage. However, the assessment of their health risks is not perfect yet. Concentrated on the EPFRs in PMs, this paper summarized the occurrence characteristics of EPFRs in PMs in different regions, different seasons and different particle sizes, analyzed its source and generation mechanism, compared the advantages and disadvantages of existing determination methods, and discussed its health risk and related evaluation models. The related research work in the future is also prospected.

Hydrogen energy is regarded as an ideal energy carrier for the future. Traditional hydrogen production through fossil fuel reforming fails to fundamentally address carbon emission issues. Direct seawater electrolysis has emerged as a promising hydrogen production technology with significant prospects. Compared to conventional pure-water electrolysis systems, natural seawater exhibits a more complex chemical composition and induces additional side reactions during electrolysis, thereby imposing higher requirements on electrode materials and electrolyzer structural design. The chlorine evolution reaction (CER) at the anode and calcium/magnesium ion precipitation at the cathode constitutes two critical challenges in direct seawater electrolysis. While substantial research has been reported in recent years regarding the mechanisms and suppression strategies of CER, comparatively fewer studies have systematically addressed the fundamental mechanisms and inhibition approaches for cathodic calcium/magnesium deposition. Practical hydrogen production processes require particular attention to electrode performance degradation caused by such inorganic precipitates, including increased mass transfer resistance and reduced electrolysis efficiency. This review initiates from the formation mechanisms of calcium/magnesium precipitation on cathode surfaces, elaborates on the fundamental principles and technical challenges of direct seawater electrolysis, and critically summarizes recent advances in suppression strategies against cathodic inorganic deposition. Furthermore, perspectives on future research directions for seawater electrolysis technology are provided, emphasizing the need for comprehensive investigations into electrode-electrolyte interfaces and scalable system optimization.

Zero-valent iron (ZVI) and its surface-modified materials have been widely used for the removal of various pollutants due to their excellent reduction properties. The three recognized potential reduction pathways of ZVI include direct electron transfer reduction, Fe(II) reduction, and atomic hydrogen reduction. Due to varying interpretations among researchers regarding the three reduction pathways and the diverse methods employed to detect them, recent studies have yielded differing conclusions on several critical aspects, including: (1) the dominant reduction pathway for pristine ZVI materials; (2) the impact of sulfur modification on the generation or recombination of atomic hydrogen; (3) the role of carbon modification in enhancing the reduction performance of ZVI through accelerated direct electron transfer or atomic hydrogen production; (4) and the underlying mechanisms by which different transition metal modifications influence the dominant reduction pathways of ZVI, among others. These discrepancies have sparked debates concerning the predominant reduction pathways involved in the removal of pollutants by ZVI and its surface-modified materials. This review systematically summarizes the following points: (1) the structure and modification principles of ZVI and its surface-modified materials; (2) the mechanisms and detection methods of the three reduction pathways in ZVI reduction systems; (3) the influence of different surface modification techniques (sulfur modification, carbon material modification, and transition metal modification) on the reduction pathways and the existing controversies; (4) the interference of environmental conditions (pH, coexisting ions, and natural organic matter) on the reduction pathways. Based on the reduction pathways, the review also presents prospects for future research directions, with the aim of addressing some of the current uncertainties in reduction pathway research and promoting a unified understanding of ZVI reduction pathways, thereby advancing scientific research and development in ZVI and its surface-modified materials.

With the rapid development of the economy and society, various types of new chemicals are constantly emerging, and have been widely applied in daily life and work, including medical devices, metal jewelry, beauty and personal care products, and smart wearable products. However, the adverse skin reactions caused by contact with these daily products seriously threaten human health and reduce the quality of life of patients. Therefore, it is of great significance to evaluate the adverse skin reactions of daily necessities and their ingredients. These evaluations aid in identifying potentially hazardous chemicals, and guiding the effective management of the product manufacturing. Traditional methods for evaluating adverse skin reactions have relied heavily on animal experiments. But in light of concerns regarding animal welfare and the need for improving test throughput and prediction efficacy of methods, great efforts have been made to develop various in vivo and in vitro alternative methods. Against this backdrop, the mechanisms of adverse skin reactions, especially for skin irritation/corrosion, atopic dermatitis and allergic contact dermatitis, and their evaluation methods were summarized in this review, based on a large number of studies published in recent years. Finally, the shortcomings and perspectives of research in this field are prospected.

In recent years, a series of organic room temperature phosphorescence materials with circular polarization luminescence have been constructed by combining （circularly polarized room temperature phosphorescence, CPRTP）materials with reasonable molecular design. The luminescence principle of CPRTP materials is consistent with the luminescence of organic room-temperature phosphorescence materials, and is accompanied by the property of circularly polarized luminescence. This kind of material not only retains the advantage of low energy loss in circular polarization luminescence, but also greatly expands the application of organic room-temperature phosphorescence materials in the fields of anti-counterfeiting encryption and afterglow display. In this paper based on the luminescence mechanism and molecular strategy of CPRTP materials, the structural design strategy of CPRTP materials is summarized. Finally, the existing problems of CPRTP materials are discussed, and the future development prospects and challenges are prospected.

In recent years, Pickering emulsions have attracted substantial attention owing to their facile preparation and superior stability. Characterized by solid-particle stabilization, these emulsions distinguish themselves from surfactant-stabilized emulsions through heightened stability, diminished toxicity, and stimulus-responsiveness. Solid particles, acting as the core part of the emulsion system, play an important role in the preparation and application of Pickering emulsions. Here, this review concentrates on the impact of various single stimulus responses (pH, temperature, carbon dioxide, redox, light irradiation, magnetic fields) and multiplexed stimulus responses on the stability and performance of Pickering emulsion systems. Additionally, it highlights the latest research and advancements concerning the application of Pickering emulsion systems in a multitude of reactions, such as oxidation, reduction reaction, hydrolysis reaction, condensation reaction, esterification transesterification reaction, and cascade reaction.

Air pollution is a major challenge for the improvement of urban environmental quality. The process of urbanization is an important cause of highly complex air pollution, on the other hand it also provides artificial reinforcement conditions for self-purification of air pollutants in cities. "Environmental catalytic city" refers to the spontaneous catalytic purification of low concentration gaseous pollutants in the atmosphere by catalytic materials coating on the artificial surfaces, such as building surfaces in the city under natural photothermal conditions. "Environmental catalytic city" is of great significance for the control of complex air pollution without additional energy consumption, the continuous improvement of indoor and outdoor air quality, and the scheme and construction of " self-purifying city". Here, we propose the concept of “environmental catalytic city”, and discuss its further improvement, development, and application.

Lignocellulose aerogels possess excellent properties of low density, high porosity, low thermal conductivity and so on, making them widely utilized in thermal insulation, adsorption, catalysis, electromagnetic shielding, biomedical and other fields. Moreover, as a bio-based material, lignocellulose is a green, pollution-free, renewable, and sustainable material. In this paper, the latest research progress of wood-based cellulose and agricultural waste-based cellulose aerogels are reviewed. Then the current research status of lignocellulose aerogel preparation methods including freeze-drying, supercritical drying, and atmospheric drying, is summarized. In addition, for the flammability issues commonly found in lignocellulose aerogels, commonly used methods to improve the flame retardancy of lignocellulose aerogels are discussed in detail. Finally, this paper concludes the main problems in lignocellulose aerogel preparation methods and properties, and the future development direction in this field is proposed.

Water is a clean, safe, environmentally benign chemical reaction medium. Understanding the properties of water and the chemical processes in hydrothermal systems is of vital significance in the research of condensed matter chemistry. The physicochemical features of water under hydrothermal conditions greatly differ from that under normal condition, and thus the hydrothermal technique has been extended to much broader systems. In this review article, we introduce the structures of water and its clusters, the variation of their properties along with conditions, and relevant condensed matters in hydrothermal systems. We also illustrate the hydrothermal chemistry through discussing the preparation of typical materials through hydrothermal methods, hydrothermal organic reactions, and bio-hydrothermal chemistry. By relating condensed matter and hydrothermal chemistry, we hope this review will offer new ideas for comprehending hydrothermal reaction systems from the angle of condensed matter chemistry.

Fuel cell technology and its industrialization have been developed rapidly in China in recent years. However, the high cost of the fuel cell caused mainly by the using of precious Pt catalysts is still one of the most important factors restricting the development of fuel cell commercialization. It is of great significance to develop low Pt catalysts with much higher catalytic efficiency and lower Pt loadings. In recent years, Pt-based catalysts with three-dimensional morphology or nanostructure have been emerged as a type of ultra-important low Pt catalysts, due to their special morphologies/structures, their catalytic activity are usually much higher than that of the widely used Pt/C catalysts. In this paper, the research progress of Pt-based catalysts with special three-dimensional morphology (such as nanoframe structure, flower-like structure, nanocage structure, sea urchin structure, etc.) and their applications in fuel cells are reviewed, meanwhile, some weaknesses and challenges of these catalysts are concluded; Furthermore, the future development and application of these catalysts are prospected.

Photoacoustic (PA) imaging, as a new type of imaging technique that offers strong optical absorption contrast and high ultrasonic resolution, shows great application prospects in the early disease diagnosis for its characteristics of deep tissue penetration and high spatial resolution. However, traditional "always on" PA contrast agents have many disadvantages such as low signal-to-noise ratio, poor selectivity and specificity. In contrast, activatable PA contrast agents, where the imaging signal can be changed in response to pathologic parameters, have shown decreased background signal and improved selectivity and specificity in early disease detection. Moreover, these contrast agents can obtain pathological parameters and information of various diseases at the molecular level by rational design to their structures, providing important guidelines for the optimization of treatment options. Therefore, activatable PA contrast agents hold greater promise in clinical practice than traditional "always on" PA contrast agents. In this review, we describe the recent advances in the development of activatable PA contrast agents. The design mechanisms and proof-of-concept applications of these activatable PA contrast agents are summarized in detail. The use of these activatable probes to detect different pathologic parameters (such as metal ions, enzymes, reactive nitrogen and reactive oxygen) is highlighted. Finally, current challenges and future perspectives in this emerging field are also analyzed.

The elemental sulfur as an active cathode material in lithium sulfur batteries possess a high theoretical energy density of 2600 Wh/kg, which is 5~6 times higher than that of traditional Li-ion batteries. Thus, the use of lithium sulfur batteries can significantly prolong the endurance mileage of electric cars and working time of electronic products. However, lithium sulfur batteries are suffering from the dissolution of polysulfide in the electrolyte during charging and discharging process, which can cause dramatic loss of active materials in the cathode. In order to suppress the problem of polysulfide dissolution, strategies such as porous modification and polarization were applied to increase the sulfiphilicity of cathode host. The biomass fibers are natural nanomaterial source to obtain cathode host materials which typically possess natural abundant hierarchical pores and heteroatoms. The porosity and heteroatom doping properties of biomass fiber derived host materials can be used to trap polysulfide via chemical and physical adsorption in cathode. The application of such materials in cathode are beneficial for slowing down the decay rate of cycling stability in lithium sulfur batteries. This review provides an overview and discussion on the application, working mechanism, problems and prospects of the biomass fibers derived cathode host for lithium sulfur batteries.

In recent years,the use of abundant and renewable biomass resources to prepare high value-added chemicals and liquid fuels is one of the hot spots in the chemical research field,which is in line with the national strategy of sustainable development. 5-hydroxymethylfurfural(HMF)is one of the key biomass platform compounds,widely used in the preparation of fine platform compounds,drug intermediates,polymer synthesis and liquid fuel precursor. Therefore,the selective oxidation of HMF has gradually become a research hotspot in the field of biomass. This paper mainly introduces the research on preparation of biomass derivatives such as DFF,FFCA and FDCA by selective oxidation of HMF in last five years,and the transformation of biomass with HMF as intermediate. The selective oxidation of HMF mainly focuses on two ways:thermalcatalytic and photocatalytic. Among them,the selective oxidation of HMF to DFF and FDCA by thermalcatalytic is widely studied. The catalytic system under this approach mainly introduces the noble metals and non-precious metals. In the few photocatalytic pathways,the main catalytic system is g-C₃N₄ catalyst. In addition,the deficiencies in there search on the oxidation of HMF are pointed out and the possible solutions are proposed.