Polychlorinated naphthalenes (PCNs) are persistent organic compounds that are regulated by the Stockholm Convention. Because of their persistence and long-range transport, PCNs are widely distributed in the environment, even in the Tibetan Plateau and Arctic area. Historical manufacturing and unintentional release from human industrial activities are the two major sources of PCNs. Accurate characterization of PCNs is essential for the development of targeted pollution prevention strategies and effective reduction of their residual levels in the environment. In this paper we summarize the current status of emission studies on PCNs, including their emission sources, emission factors and progress in emission inventories. Historical emission studies show that PCN emissions are closely related to the industrialization process, with an increasing and then decreasing trend in most regions. Studies on unintentional emissions show that the emission factors of PCNs vary considerably between industries and processes and are strongly influenced by pollution control measures. Although some progress has been achieved, the systematic study of global emissions of PCNs is still inadequate, particularly in the determination of emission factors and the compilation of emission inventories. Future research is needed to further improve the emission inventory and strengthen monitoring and management to effectively control the environmental risks of PCNs.

Contents

1 Introduction

2 Properties of PCNs

2.1 Physicochemical properties of PCNs

2.2 Toxicity of PCNs

2.3 Environmental behavior of PCNs

3 Current status of global management policies for PCNs

4 Source of PCNs

5 Progress in the study of historical production and emission of PCNs

5.1 Estimation of historical production

5.2 Release of PCNs as historical chemicals

6 Unintentional emissions of PCNs

6.1 Emission factors for PCNs

6.2 Emission inventories of PCNs

7 Conclusion and outlook

Since the widespread acceptance between 1960s and 1970s, the condensed matter physics has undergone rapid development. Condensed matter physics primarily investigates the geometric and electronic structures of solid and liquid substances, as well as the resulting microscopic and macroscopic physical phenomena such as sound, light, electricity, magnetism, heat, etc. Meanwhile, the field of chemistry has also evolved significantly, especially in the last two decades, with advancements in theoretical chemistry and chemical characterization techniques. Researchers have gradually come to realize that chemical reactions are not merely straightforward transformations from reactants to products. The structural hierarchy of the reaction system plays a crucial role in the progression of chemical reactions. There has been a growing emphasis on the in-situ characterization of chemical reactions, and efforts have been made to explore the dynamic changes in the material structures at different levels within the system under reaction conditions. These developments can be considered as the nascent stages of condensed matter chemistry research. Physics and chemistry have always been intertwined and mutually reinforcing natural sciences. Currently, new phenomena and theories in condensed matter physics continue to emerge. Introducing these new physical phenomena and theories into chemical research is a highly worthwhile exploration area. The present review will briefly introduce some relatively recent concepts in condensed matter physics (e.g., surface plasmon polariton, topological insulators, quasicrystals, local micro-electric/magnetic fields, light-matter interactions, alternating magnets, etc.) and their applications in chemistry. The aim is to illustrate the application potentials of cutting-edge condensed matter physics research in chemistry, provide insights into advancing traditional chemical research to the realm of condensed matter chemistry, and contribute to the development of condensed matter chemistry.

Contents

1 Introduction: From solid-state physics to condensed matter physics

2 Condensed matter in chemical reaction systems

2.1 Dynamic interface configurations in reactions

2.1.1 Reactions on solid-gas interfaces

2.1.2 Reactions on solid-liquid interfaces

2.1.3 Reactions on solid-Solid interfaces

2.2 External electric field

2.3 Other external fields

2.4 Microenvironments

3 New chemical methods from the new concepts of condensed matter physics

3.1 Quantum confinement effects

3.2 Surface plasmon polariton

3.3 Topological insulator

4 Conclusion and outlook

Thermally activated delayed fluorescence (TADF) materials have entered a new stage of vigorous development with the significant advantage of efficient utilization of single and triplet excitons without the need of precious metals. However, the aggregation-induced burst (ACQ) phenomenon is prevalent in conventional TADF materials, which severely limits their development and application. In contrast, aggregation-induced delayed fluorescence (AIDF) materials have a unique aggregation-induced fluorescence enhancement phenomenon, thus attracting much attention in the field of organic electroluminescence. In this review, we summarize the relevant AIDF molecules in the field of organic light-emitting diode (OLED), focusing on the molecular design of AIDFs and their research and application progress in the field of non-doped OLEDs since 2021, and analyze and discuss the mentioned AIDF molecules by classifying them based on the basis of their molecular structures, respectively, in terms of benzophenones, triazines, quinoxalines, and other receptors. compounds are structurally disassembled and properties are summarized, the conformational relationships between their structures and properties are deeply explored, and the outlook for the development of this field is made.

Contents

1 Introduction

2 Benzophenone and its derivatives

3 Diphenyl sulfone and its derivatives

4 Triazine and its derivatives

5 Quinoxaline and its derivatives

6 Other receptors

7 Conclusion and outlook

Electrochemical carbon dioxide reduction reactions (CO₂RR) have become an important means of building sustainable energy systems due to their potential to convert carbon dioxide into high-value chemicals under mild conditions, as global carbon dioxide emissions become increasingly serious. This review provides a systematic overview of the research progress in the construction of CO₂RR electrodes, with a focus on the structural design principles of the electrodes. It highlights typical construction strategies for metal-based, carbon-based, and emerging electrode structures, analyzing the effects of conductivity, pore structure, and three-phase interface stability on electron transport, carbon dioxide mass transfer, and product desorption behavior.

It particularly emphasizes the crucial role of surface and interface engineering in enhancing catalytic selectivity and long-term stability, and summarizes cutting-edge construction methods such as 3D printing, bio-inspired modification of electrodes, and the use of derivative materials. Although existing research has made significant progress under laboratory conditions, challenges such as structural stability, construction costs, and large-scale manufacturability remain to be addressed in practical applications. Therefore, this review proposes that future research should be conducted in a coordinated manner in the areas of interface microenvironment control, structural modeling, and manufacturing process simplification to achieve efficient, stable, and scalable CO₂RR electrode systems.

Contents

1 Introduction

2 CO₂RR mechanism

3 CO₂RR Electrode Construction

3.1 Transition metal-based

3.2 Carbon-based

3.3 Emerging Structures and 3D Printed Electrodes

4 Surface and Interface Engineering

5 Conclusion and outlook

Recent advances in machine learning (ML) have demonstrated remarkable potential in revolutionizing the design, property prediction, and synthesis optimization of nanomaterials, facilitating a paradigm shift from traditional empirical approaches to data-driven methodologies in nanoscience. This review systematically examines the research frameworks and cutting-edge developments in ML-assisted nanomaterial design and fabrication, with a focus on representative material systems, including zero-dimensional quantum dots, one-dimensional nanotubes, two-dimensional materials, and metal-organic frameworks (MOFs). Key technical aspects such as data acquisition and feature engineering, supervised and unsupervised modeling, generative algorithms, and automated experimental platforms are critically discussed. Furthermore, we highlight emerging challenges and future directions, emphasizing the need for standardized databases, physics-informed ML models, and closed-loop experimental systems to enable intelligent and efficient nanomaterial development. This work provides a comprehensive methodological reference for the integration of ML in next-generation nanomaterial research.

Contents

1 Introduction

2 Machine Learning Application Framework

2.1 Acquisition and Standardized Preprocessing of High-Quality Data

2.2 Representation Methods and Feature Engineering for Material Structures

2.3 Model Construction and Training

2.4 Validation and Generalization Assessment

2.5 Performance Prediction and Material Screening

2.6 Inverse Design and Generative Structural Optimization

3 Representative Research Progress

3.1 Zero-Dimensional Nanomaterials

3.2 One-Dimensional Nanomaterials

3.3 Two-Dimensional Nanomaterials

3.4 Metal-Organic Frameworks

4 Conclusion and Outlook

The electrocatalytic urea oxidation reaction (UOR) has emerged as an energy-efficient alternative to the traditional oxygen evolution reaction for hydrogen production, with mechanistic understanding being critical for the rational design of catalysts. This review systematically summarizes recent advances in in situ characterization techniques for elucidating the dynamic reaction mechanisms of UOR. Studies reveal that phase transitions, valence state migration, and electronic structure evolution of catalysts under operational conditions are key factors governing activity and stability. Techniques such as in situ X-ray diffraction, X-ray absorption spectroscopy, Raman spectroscopy, and Fourier-transform infrared spectroscopy enable real-time monitoring of catalyst reconstruction, intermediate evolution, and interfacial adsorption behavior, overcoming the environmental deviations inherent in conventional ex situ characterization. When combined with theoretical calculations, these methods provide direct evidence for identifying active-site configurations, reaction pathways, and rate-determining steps. In addition, special emphasis is placed on multimodal in situ strategies for deciphering synergistic effects in nickel-based catalysts, while current challenges including non-alkaline systems, real wastewater environments, and multi-metal cooperation mechanisms are critically discussed. Future research should focus on developing novel in situ approaches for complex systems and establishing a mutually reinforcing framework integrating theoretical prediction and experimental validation, thereby advancing UOR catalyst design from empirical exploration to mechanism-guided optimization.

Liquid crystal elastomers (LCEs) are crosslinked polymer networks that combine the anisotropy of liquid crystals with the entropic elasticity of elastomers. They exhibit reversible large deformations under external stimuli, making them a focal point in smart materials research. Among various forms, LCE fibers, characterized by their high aspect ratio and large specific surface area, demonstrate enhanced sensitivity, greater deformation capacity, and excellent reversibility, weavability, and programmability, significantly broadening their application potential. In recent years, advancements in manufacturing technologies have expanded the fabrication methods of LCE fibers from traditional pulling and templating techniques to advanced spinning technologies such as melt spinning, electrospinning, wet spinning, and emerging 3D/4D printing techniques. These innovations have not only provided more possibilities for structural design and performance optimization of LCE fibers but also promoted their widespread use in high-performance material applications. This article systematically reviews the molecular structure and diverse fabrication methods of LCE fibers, discusses their applications in artificial muscles, soft robotics, smart clothing, and wearable devices, and provides an outlook on the future development of LCE fibers.

D-A-D molecule refers to a class of conjugated structure molecules composed of an electron donor and an electron acceptor. The NIR two-region fluorescence imaging dominated by such molecules has the advantages of good penetration effect and high imaging clarity. It has high application potential in clinical diagnosis. However, such molecules usually contain conjugated benzene ring structures. This means that the water solubility of these molecules is not good, which greatly limits the wider application of NIR-Ⅱregion fluorescence imaging. In recent years, D-A-D molecules have usually been modified to improve their water solubility. This review introduces four methods to improve water solubility by end-modified hydrophilic polyethylene glycol, modified other hydrophilic polymer chains, modified by protein or peptide, and end-ionized modification. The design methods and related applications of water-soluble D-A-D molecules are introduced in detail. Finally, the further development of water-soluble D-A-D small molecules in the field of NIR-Ⅱ region fluorescence imaging is prospect.

Nucleic acid testing is the gold standard and technological cornerstone for the modern diagnosis of pathogenic infections. As a deployable public health surveillance technology, Point-of-Care Testing (POCT) has demonstrated significant value in infectious disease prevention and control, personalized precision medicine, and medical scenarios with limited resources. POCT technology can rapidly provide diagnostic information, significantly improve patient outcomes, and optimize the allocation of medical resources. As an emerging technology, microfluidic chips have become a key component in POCT due to their low reagent consumption, high integration, and automation. By integrating laboratory functions onto a single chip, microfluidic devices have achieved full-process automation of sample processing, signal amplification, and detection, greatly enhancing the efficiency and accuracy of testing. Moreover, when combined with isothermal amplification techniques (such as LAMP) and CRISPR-Cas technology, microfluidic chips can rapidly and sensitively detect pathogens, making them suitable for on-site screening of various infectious diseases. Currently, POCT devices based on microfluidic chips have been successfully applied in the detection of pathogens such as SARS-CoV-2, demonstrating the advantages of speed, portability, and high sensitivity. This review aims to summarize the development of nucleic acid detection and the research progress on the combination of CRISPR-Cas technology and microfluidic chips to explore their current applications and future prospects for POCT.

Brine resources are widely present in salt lakes, groundwater, and seawater. They are rich in many valuable elements such as lithium, potassium, magnesium, and boron, and thus possess significant economic value. With the rapid development of the new energy industry, especially the sharp increase in the demand for lithium resources, the comprehensive utilization of brine resources has become crucial for ensuring the sustainable supply of resources and promoting green development. However, traditional brine treatment methods, such as evaporation crystallization and chemical precipitation, have problems like high energy consumption, low separation precision, and environmental pollution. There is an urgent need for more efficient and environmentally friendly technical means. As a separation technology based on ion exchange membranes and the action of an electric field, electrodialysis technology has remarkable advantages such as high efficiency, energy conservation, and environmental friendliness, and has gradually become an important technology in brine resource treatment. This article introduces the principles of electrodialysis technology, including the working mechanisms of anion and cation membranes and bipolar membranes. By combining application cases, it explores the research progress of electrodialysis technology in the comprehensive utilization of brine resources. In terms of separation and extraction, this technology has a remarkable effect on the separation and extraction of elements such as lithium, boron, and potassium. It has outstanding advantages, especially in the extraction of lithium from brine with a high magnesium-to-lithium ratio. In the concentration process, it can achieve brine concentration with low energy consumption. In product processing, it can improve product purity and optimize the production process. Although electrodialysis technology has achieved remarkable results in the laboratory and pilot - scale stages, it still faces challenges such as the durability of membrane materials and equipment costs in large - scale industrial applications. In the future, electrodialysis technology is expected to develop synergistically with other technologies. Differentiated technical solutions will be developed according to the characteristics of different brine resources to achieve the full-component utilization of brine resources and promote the sustainable development of related industries.

Phthalocyanine transition metal macrocyclic complexes have been widely applied in electrochemical reaction processes related to energy conversion and storage, including catalytic oxygen reduction reaction (ORR) and oxygen evolution reactions (OER), etc. Their excellent bifunctional performance in catalytic oxygen reactions has attracted extensive attention. This article mainly reviews the preparation methods and current research progress of metal phthalocyanine-based catalysts, as well as the factors influencing the performance of metal phthalocyanine-based catalysts, such as the structure of metal phthalocyanine, the support, the synergistic effect of central metal ions and bimetallic ions, and the influence of edge modification groups, etc. The influence of the fully conjugated structure on its thermal stability and the improvement of catalytic performance was analyzed; The π-π interaction between polymeric metal phthalocyanine complexes and three-dimensional graphene is conducive to improving catalytic activity and durability. The synergistic effect between the two metals and the edge-modified electron-donating groups can enhance catalytic performance.

As environmental challenges continue to escalate, the importance of energy storage development has never been greater. The design and advancement of high-performance batteries are now essential to meet the demands of modern society. However, existing battery substrates are inadequate for the production of next-generation batteries. Metal-Organic Frameworks (MOFs) have emerged as a novel class of multifunctional materials that offer significant advantages as battery substrates, including high specific surface area, exceptional porosity, and customizable properties. This review comprehensively examines the applications of various MOF substrates in the field of battery electrodes, and delves into innovative application strategies, challenges and outlines future development prospects for MOF electrode substrates, emphasizing their transformative potential in enhancing electrode performance, paving the way for their integration into sustainable energy solutions.

Inconel 718 (IN 718) alloy owing to its high temperature strength, high ductility and good corrosion resistance, has broad application prospects in aerospace, military and energy fields. However, the low hardness and wear resistance of IN 718 alloy severely limits its application. To solve these problems, the feasible strategy is to modify the compositions/microstructures of IN 718 alloy. Laser additive manufacturing method has the capability of effectively regulating the composition and microstructure of composite materials, so as to enhance their overall mechanical performances. Herein, the intrinsic properties and compositional modification strategies of IN 718-matrix composites were first introduced, and then the advantages and limitations of laser-additive-manufactured IN 718-matrix composites were summarized. Afterward, the evolution laws of microstructural morphologies and mechanical performances of IN 718-matrix composites prepared by laser additive manufacturing methods are summarized. Finally, the key scientific problems in modifying the preparation method, regulating microstructure and optimizing mechanical performances of IN 718-matrix composites were respectively clarified, and the future developments were prospected.

In the era of heightened global environmental consciousness, the principle of sustainable development has become deeply ingrained in public awareness. However, conventional petroleum-based adhesives are plagued by issues of unsustainability, high energy consumption, and significant environmental pollution during their production and application. Consequently, the development of green, sustainable, and high-performance biomass-based adhesives has emerged as a critical research focus. Biomass-based adhesives continue to encounter significant challenges, including suboptimal water resistance, elevated production costs, and the necessity for enhanced environmental performance. Future research should focus on optimizing the modification process of biomass raw materials, reducing production costs, improving the comprehensive properties of adhesives, and promoting their large-scale industrial application. In-depth investigation into the correlation between the structure and properties of biomass is crucial for the development of environmentally friendly and cost-effective adhesives. This paper summarizes the classification, modification methods, and properties of biomass-based raw materials and provides a detailed prospect for their future development.

Methane, as a light alkane clean resource with abundant reserves, its efficient utilization has significant practical significance. Direct conversion of methane into high-value target products through gas-phase selective oxidation of methane has become an effective way to efficiently utilize methane. This reaction has the advantages of simple equipment and relatively low reaction energy consumption. However, the strong carbon-hydrogen bond of methane makes its activation process difficult, and the product formaldehyde is prone to deep oxidation under high-temperature and oxygen-containing conditions, resulting in a decrease in the selectivity of the target product. Therefore, achieving high-selectivity direct oxidation of methane to form oxygen-containing compounds is challenging. This article reviews the research progress in the gas-phase selective oxidation of methane to formaldehyde, focusing on the reaction mechanism of selective oxidation of methane to formaldehyde on catalysts, catalyst systems, and the application of various in-situ characterizations in the reaction. Finally, the future development directions of the selective oxidation of methane are summarized and prospected.

The increasing proportion of nuclear energy in China’s energy resources has brought about a series of difficulties and challenges. Nuclear power plants generate a large amount of radioactive liquid and solid waste during operation, and how to effectively treat and dispose of them has become a research focus. For radioactive liquid waste, the current main treatment processes in China are ion exchange and barrel evaporation drying. In addition, chemical precipitation, membrane technology, and other emerging technologies are also the current research directions for combined treatment. For solid waste, radioactive ions are tightly bound to solid materials, making it difficult for decontamination and regulatory release. Currently, solidification and compression are used for disposal in China, especially for mixed waste resins, which have large output and high radiation dose, as well as water absorption and elasticity, the main method in China is to use hot state overpressure technology to improve the volume reduction ratio, and then package and dispose of it geologically..

Cell heterogeneity is key to understanding life processes such as embryonic development and disease evolution, while traditional bulk cell RNA sequencing cannot resolve gene expression differences at the single-cell level. Although single-cell RNA sequencing (scRNA-seq) technology can construct transcriptomic maps at single-cell resolution, it faces challenges such as low efficiency in single-cell isolation and capture, and large deviations in trace RNA manipulation. Microfluidic chip technology, through a microscale fluid manipulation system, integrates processes such as single-cell isolation, lysis, reverse transcription, amplification, and sequencing library construction, achieving high-throughput, low sample loss, and automated operations, which significantly improves the efficiency and data reliability of scRNA-seq. This paper outlines the sequencing process of scRNA-seq, including steps such as single-cell isolation and capture, RNA extraction, reverse transcription and amplification, and single-cell sequencing. It analyzes the core advantages of microfluidic chips in adapting to single cells, precisely controlling reaction volumes, and realizing process automation, and briefly describes the technical principles and characteristics of representative platforms such as Fluidigm C1, 10X Genomics Chromium, and BD Rhapsody. Microfluidic chip technology provides an efficient and precise technical platform for scRNA-seq. In the future, with the continuous optimization of chip design and the improvement of multi-omics integrated analysis capabilities, we expect it to play a more profound role in resolving complex biological systems, revealing disease mechanisms, and even promoting precision medicine.

With the increasing global emphasis on carbon dioxide emissions reduction, electrocatalytic carbon dioxide reduction (ECO₂R) to methanol has garnered significant attention within the context of carbon neutrality. However, existing ECO₂R catalysts still suffer from limitations in activity, selectivity, and stability, thereby constraining their practical applications. This underscores the urgent need for the development of highly efficient catalysts, which remains a central research focus in this field. Traditional catalyst design predominantly relies on trial-and-error approaches, which are inherently inefficient. Therefore, novel strategies are required to accelerate catalyst discovery and optimization. With the rapid advancement of artificial intelligence, machine learning has emerged as a powerful tool to drive catalyst development. This review systematically summarizes the reaction mechanisms underlying ECO₂R to methanol and highlights recent advancements in catalyst research, encompassing Cu-based, non-Cu-based, and phthalocyanine-based catalysts. Furthermore, the fundamental framework of machine learning applications in this domain is introduced, covering key stages from data acquisition to model validation. Particular emphasis is placed on machine learning-driven predictions of catalytic activity, catalyst design, and performance optimization. Although machine learning has made remarkable progress in ECO₂R research, there are still several challenges, including data scarcity, insufficient model interpretability, and the lack of a universal prediction framework. Future research should focus on the establishment of high-quality catalyst databases, enhancement of model interpretability, and improvement of generalization capabilities. This review aims to provide a comprehensive perspective on ECO₂R catalyst design while emphasizing the pivotal role of machine learning in facilitating breakthroughs in this field.

The extensive use of chemical fertilizers and other industrial and agricultural chemicals has led to the discharge of excessive nitrate wastewater into nature, posing a serious threat to the environment and human health. Photocatalytic nitrate reduction technology is considered to be a promising, harmless treatment method for nitrate due to its high efficiency, low energy consumption and wide applicability. In this paper, the mechanism and main products of nitrate reduction in photocatalytic water are described in detail. The commonly used photocatalyst types are systematically reviewed, and the influencing factors in the photocatalytic process are introduced. In addition, the main challenges faced by photocatalytic nitrate reduction technology are comprehensively analyzed, and its future development prospects are discussed and prospected.

Mirror-image peptides and proteins composed entirely of D-amino acids have emerged as promising therapeutic candidates owing to their resistance to proteolysis and reduced immunogenicity. Mirror-image phage display (MIPD) is currently the main experimental technique for identifying mirror-image peptide ligands targeting disease-related proteins. However, the success of MIPD critically depends on synthetic mirror-image target proteins, which cannot be produced by traditional recombinant methods due to the intrinsic chirality of biological systems. Recent advances in chemical protein synthesis, such as enzyme-cleavable solubilizing tags, backbone-installed split intein-assisted ligation, and removable glycosylation modification-assisted folding strategies, have effectively addressed key challenges in preparing these complex mirror-image proteins. In addition, computational approaches, exemplified by AI-driven protein design, have become powerful complementary tools, accelerating the discovery and optimization of mirror-image protein drug candidates. Although mirror-image protein drugs have not yet reached clinical use, ongoing innovations in chemical synthesis and ligand screening methods are steadily advancing their therapeutic potential toward clinical translation.

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.