With the rapid development and increasing maturity of photopolymerization-based 3D printing technology, the market demand for photopolymer resins has become increasingly diverse and refined, driving the research and development of multifunctional photopolymer resins. The aim is to expand the application scope of photopolymer resins, particularly in the fields of high-performance and intelligent materials. As an emerging research direction, self-healing 3D-printed polymer materials have garnered significant attention from researchers in recent years. In this article, the latest progress in both intrinsic self-healing polymer materials based on mechanisms such as hydrogen bonding, disulfide bonds, coordinate bonds, and host-guest interactions and extrinsic self-healing polymer materials, such as those utilizing microcapsules and hollow fibers is reviewed. Different repair mechanisms of intrinsic and extrinsic systems are explored, with a focus on analyzing their application in the field of 3D printing. Currently, research on self-healing 3D-printed polymer materials is mainly concentrated on intrinsic self-healing materials. For rigid solid polymer materials requiring 3D printing and self-healing capabilities, extrinsic self-healing methods, mainly microcapsule-based and microvascular network-based self-healing approaches, are still required.

Contents

1 Introduction

2. Intrinsic self-healing

2.1 Hydrogen bond based self-healing

2.2 Coordinate bond based self-healing

2.3 Host-guest interaction based self-healing

2.4 Diels-Alder rection based self-healing

2.5 Hydrazone bond based self-healing

2.6 Disulfide bond based self-healing

3. Extrinsic self-healing
3.1 Microcapsule type self-healing material

3.1 Microvascular type self-healing material

4 Conclusion and outlook

Lithium metal batteries (LMBs) have emerged as a focal point for next-generation battery technology research due to their high energy density. However, the commercialization of lithium-metal batteries is hindered by a series of challenges, including lithium dendrite formation, volumetric expansion, and the rupture of the solid electrolyte interphase (SEI). Ionic liquids (ILs) are emerging as key candidate materials to address these issues due to their unique physical and chemical properties. Despite the significant potential of ionic liquids in lithium-metal batteries, several pressing issues, such as high costs and high viscosity, need to be addressed. Future research should focus on developing new low-cost, high-performance ionic liquids and further understanding their mechanisms in batteries. Additionally, combining advanced characterization techniques and theoretical calculations to explore the dynamic behavior and interfacial phenomena of ionic liquids in lithium metal batteries will help advance their practical applications. This review summarizes the safety issues involved in the research and development of lithium metal batteries, as well as the research progress of ionic liquids in their application as electrolytes and solid electrolytes in lithium metal batteries.

In recent years, covalent organic frameworks (COFs) have emerged as focal points in the research of membrane materials. Distinguished by their distinctive porous structures and structural versatility, COFs offer a promising avenue for advancement in membrane applications compared to conventional polymeric materials. This article delves into diverse interfacial systems, systematically detailing the methodologies for fabricating high-performance COF membranes via interfacial polymerization. The mechanisms underlying membrane formation across various interfacial systems and the strategies for precisely controlling the membrane structure will be elucidated. Furthermore, the intricate relationship between the membrane structure and application performance will be summarized. The challenges and perspectives in this field will be highlighted in the last part of this review.

Contents

1 Introduction

2 Gas/liquid interface polymerization

2.1 Langmuir-Blodgett method

2.2 Surfactant-mediated

3 Liquid/liquid interface polymerization

3.1 Regulation of the system

3.2 Additive-mediated

3.3 Optimizing synthetic conditions

4 Liquid/solid interface polymerization

5 Solid/gas interface polymerization

6 Applications of COF membrane

6.1 Water resource treatment

6.2 Gas separation and storage

6.3 Membrane catalysis

6.4 Electric device

7 Conclusion and outlook

Using catalytic processes to convert CO₂ into low-carbon fuels and fine chemicals is one of the most efficient paths to addressing global energy imbalance and CO₂ excess emissions. The advantages of one-dimensional nanocatalysts in long-range electron transport and controllable internal structure endow them with widely utilization in catalysis. Electrospinning, a top-down method for fabrication of fibers, offers unique advantages in regulating fiber composition and structure. This paper systematically reviews the designing strategies and application advancements of fiber catalysts based on electrospinning, including fully controllable synthesis strategies for multilevel structured fibers, methods for introducing active sites via one-step and post-load techniques, and research case of fiber catalysts in CO₂ conversion. This review provides valuable references for the development of new concepts, methods, processes, and applications of fiber catalysts for CO₂ conversion.

Contents

1 Introduction

2 Electrospinning in designing of fiber catalysts

2.1 Electrospinning

2.2 Designing of fiber structures

2.3 Introducing of active sites

3 Applications of fiber catalysts in CO₂ conversion

3.1 Photocatalytic CO₂ conversion

3.2 Electrocatalytic CO₂ conversion

3.3 Thermocatalytic CO₂ conversion

4 Conclusion and outlook

With the advancement of technology, flexible pressure sensors have been widely utilized in wearable device fields such as medical monitoring and motion monitoring, primarily due to their thinness, lightness, flexibility, good ductility, as well as their faster response speed and higher sensitivity compared to traditional rigid sensors. When subjected to external forces, the elastic elements within these sensors undergo deformation, converting mechanical signals into electrical signals. Consequently, the choice of elastic elements significantly impacts the overall performance of flexible pressure sensors. Polydimethylsiloxane (PDMS) is extensively used as a flexible substrate in sensors because of its stable chemical properties, good thermal stability, low preparation cost, and excellent biocompatibility. By collecting relevant information, this paper reviews the sensing mechanisms of PDMS-based flexible pressure sensors, introduces preparation techniques to improve the properties of PDMS materials, including the recently popular methods of introducing porous structures and constructing surface architectures, and discusses the applications of PDMS-based flexible pressure sensors in medical monitoring, electronic skin, and other fields. Finally, the challenges faced by PDMS-based flexible sensors and their future opportunities are prospected.

Contents

1 Introduction

2 Flexible pressure sensor

3 Fabrication technology of flexible sensor with improved performance

3.1 Pore structure

3.2 Surface Micro-Nano Structures

4 Application of flexible pressure sensor based on PDMS

4.1 Health monitoring

4.2 Electronic skin

5 Conclusion and outlook

ONOO⁻, produced by the diffusion-controlled reaction of nitric oxide and superoxide radicals, is a strong oxidizing and nitrating agent that causes damage to DNA, proteins, and other biomolecules in cells. Since ONOO⁻ is characterized by its short lifetime, high reactivity, and low concentration under physiological conditions, and the pathophysiological roles it plays in biological systems are not yet fully understood, it is of great significance to develop highly sensitive and selective detection technologies to achieve real-time dynamic monitoring of ONOO⁻. In this paper, we review the research progress of ONOO⁻ fluorescent probes in disease-related processes in the recent 5 years, revealing the potential role of ONOO⁻ in various diseases, such as inflammation, tumors, liver injury, and brain diseases. Finally, the bottlenecks in the development of ONOO⁻ probes and future trends are discussed, which will promote the application of ONOO⁻ probes in chemistry, biology, and pharmacology.

Contents

1 Introduction

2 Design strategy of ONOO⁻ fluorescent probe

3 Detection and imaging of ONOO⁻ by fluorescent probes in disease-related processes

3.1 Detection and imaging of ONOO⁻ in inflammation

3.2 Detection and imaging of ONOO⁻ in tumors

3.3 Detection and imaging of ONOO⁻ in Liver Injuries

3.4 Detection and Imaging of ONOO⁻ in Brain diseases

3.5 Detection and imaging of ONOO⁻ in other disease models

4 Conclusion and outlook

Two-dimensional nanochannel membrane is a new membrane composed of two-dimensional nanosheets with atomic layer thickness and stacked by self-assembly. Compared with traditional separation membranes, its ion separation behavior has many unique characteristics, and has important application potential in seawater desalination, energy storage and conversion, rare element extraction and separation, and other fields. These materials have attracted great interest and wide attention of researchers. It has become an important development direction and research hotspot in the field of membrane separation science and technology in recent years. In this paper, the construction strategy, performance evaluation method and mass transfer mechanism of two-dimensional nanochannel membranes were systematically summarized from the perspective of two-dimensional nanochannel membranes used for accurate ion sieving. The latest research progress in the preparation and application of two-dimensional nanochannel membranes in recent years was reviewed, and the development trend was prospected. We hope this review can provide enlightenments for structure design and optimization, performance enhancement, large-scale preparation and engineering applications of two-dimensional nanochannel membrane in the future.

Contents

1. Introduction

2. Two-dimensional nanochannel ion sieving membrane and its construction methods

2.1 Two-dimensional nanochannel ion screening membrane

2.2 Construction method of 2D nanochannel ion sieving membrane

2.3 Characterization of structure and evaluation of properties of two-dimensional nanochannel ion sieving membranes

3. Mass transfer mechanism in two-dimensional nanochannels

3.1 Mass transfer mechanism of solvent in two-dimensional channels

3.2 Mass transfer mechanism of ions in two-dimensional channels

4. Application of two-dimensional nanochannel ion sieving membrane

4.1 Desalination of seawater

4.2 Energy conversion and storage

4.3 Extraction and separation of elements

5. Conclusion and outlook

The sustained development of industry has brought enormous economic benefits, but it has also caused great harm to the environment. The excessive CO₂ emissions from fossil fuel combustion are released into the natural environment, posing a threat to the environment and human health. So people are working hard to develop materials that can effectively capture CO₂. At present, CO₂ capture mainly occurs after the combustion of fossil fuels. According to the design standards for CO₂ adsorbents, a variety of CO₂ capture materials have been designed and developed, including solid adsorbents, liquid adsorbents, and multiphase adsorbents. The adsorption mechanisms of various adsorbents are also different, including adsorption, absorption, or a combination of both mechanisms.This review focuses on the capture performance, absorption mechanism, advantages and disadvantages of various common types of current adsorbents, and introduces amine solution absorbents, zeolite-based adsorbents, ionic liquids-based adsorbents, carbon-based adsorbents, metal-organic framework materials, covalent organic framework materials, metal-oxide materials, and biopolymer nanocomposites, respectively, with an outlook of the future development of CO₂ adsorbent materials.

Contents

1 Introduction

1.1 Current status and hazards of CO₂ emissions

1.2 CO₂ capture technology

1.3 Criteria for designing CO₂ capture materials

2 CO₂ capture materials

2.1 Amine solution absorbents

2.2 Zeolites based adsorbents

2.3 Ionic liquids absorbents(ILs)

2.4 Carbon-based adsorbents

2.5 Metal organic framworks(MOF)

2.6 Covalent organic frameworks(COF)

2.7 Metal oxide sorbents

2.8 Biopolymeric nanocomposites

3 Comparison and Prospect of Capture Materials

4 Conclusion

Polyphenolic compounds are a class of naturally occurring bioactive substances widely found in environment. Their characteristics, such as low toxicity, low cost, and broad availability, make them become to be widely used chelating agents, reducing agents and capping agents for treating typical pollutants in water. Currently, polyphenols are extensively used in advanced oxidation processes (AOPs) through the coupling of common transition metal ions and peroxides. However, the chemical mechanisms of polyphenolic substances in water pollution remediation still lack systematic conclusions. This study reviews and summarizes the compositions of homogeneous and heterogeneous systems containing polyphenolic compounds, as well as the pro-oxidant, antioxidant, and chelating-reduction effects exhibited by polyphenols within these systems. It explains the main active species generated by polyphenolic substances under different systems from both radical and non-radical perspectives, along with the corresponding mechanisms for the removal of water pollutants. The dual role of polyphenols as natural redox mediators (RMs) in constructing complex catalytic systems is emphasized, and the effects of external energies such as light, heat, electricity, ultrasound, and plasma on the reaction mechanisms and pollutant degradation effectiveness in these systems are described. Finally, the article looks ahead to the future development directions of polyphenolic compounds in the field of water treatment.

Contents

1 Introduction

2 H₂O₂/PS/PAA activation

2.1 ROS of H₂O₂/PS/PAA

2.2 Polyphenols/Fe(Cu) ions/peroxide systems

2.3 Chelation and reduction of polyphenol-metal ions

2.4 Non-radical reactions

3 High-valent metal species

3.1 Fe ions

3.2 Cu ions

3.3 Mn ions

4 Solid catalyst

4.1 Zero-valent metal monomers

4.2 Monometallic compounds

4.3 Polymetallic compounds

4.4 Metal-organic complexes

4.5 Carbon-based materials

4.6 Inorganic salt supported metal catalysts

5 Polyphenol-SQ•^--Quinone

5.1 Periodate and permanganate

5.2 Peroxide

5.3 O₂, H₂O and others

5.4 Redox mediators

6 External energy

7 Conclusion and outlook

Due to HKUST-1 has ultra-high specific surface area and porosity, excellent thermal stability, and adjustable structure and function, HKUST-1 is one of the most widely studied MOFs. The HKUST-1-based composites have achieved excellent multi-component properties and demonstrated new physical and chemical properties, which have a significant impact on their applications. The structural characteristics and physicochemical properties of HKUST-1 and HKUST-1-based composites make them have broad application prospects in gas storage, gas adsorption, catalysis, drug delivery and release sensing and photodegradation. This article focuses on the application progress of HKUST-1 and HKUST-1-based composites in various fields in recent years, and finally looks forward to the research on HKUST-1-based composites.

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

Two-dimensional (2D) perovskite materials have been receiving considerable attention owing to their high stability. Despite this, there is still significant potential for improving their power conversion efficiency. Designing effective spacer cations is one of the crucial method to improve the photoelectric performance of 2D perovskite solar cells. Among the various strategies, halogen substitution has emerged as a particularly effective approach, which can fine-tune the stability and optical properties of the perovskite crystal structure, leading to notable improvements in photoelectric conversion efficiency as well as long-term stability. In recent years, there has been significant and notable progress of two-dimensional (2D) perovskites based on various halogen-substituted spacer cations in the preparation of high-performance perovskite solar cells. This paper initially provides a comprehensive overview of the development status of 2D perovskite materials and devices that employ different spacer cations. Following this, the focus shifts to an in-depth review of the advancements made in the fabrication of 2D perovskite solar cells (PSCs) and the surface modification of three-dimensional (3D) perovskites, specifically emphasizing the role of spacer cations that have been singly or multiply substituted with halogens such as fluorine, chlorine, and bromine. Finally, we present a concise discussion on the current challenges faced in this field and offer insights into the potential future directions for further research and development.

Eu-Tb lanthanide bimetallic organic frameworks (Ln-BMOFs) are inorganic organic hybrid materials with periodic network structure and functional diversification, which are composed of lanthanide Eu-Tb as the center and organic ligands. It has unique luminescence characteristics, especially sharp absorption, and large Stokes displacement, which makes it exhibit excellent performance in the field of fluorescence sensing. By adjusting the ratio of Eu and Tb in MOFs, we can obtain a series of Eu_xTb_1-x doped MOFs with different luminous colors, and containing different proportions of Eu and Tb, which have similar or different luminous sensing mechanisms. Since the Eu-Tb lanthanide bimetallic organic frameworks has important research value in the field of fluorescence sensing, this paper will comprehensively and systematically review the research progress of lanthanide bimetallic organic frameworks from the aspects of background, sensing mechanism and application of fluorescence sensing.

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.

Zinc-iodine batteries have attracted widespread attention as a novel green, low-cost, and highly safe electrochemical energy storage technology. Its basic principle is to use the electrochemical reaction between zinc and iodine to store and release energy. However, the low electronic conductivity, shuttle effect, and high solubility of iodine limit the practical application of zinc-iodine batteries. This work provides a systematic review of the research progress on carbon materials used in the cathode of zinc-iodine batteries, with a focus on several commonly used carbon materials, such as carbon nanotubes, graphene, activated carbon, biomass-derived carbon, and other porous carbon materials. Owing to their excellent conductivity, high specific surface area, and good chemical stability, these carbon materials can not only effectively adsorb and immobilize iodine molecules, preventing iodine loss and the shuttle effect, but also promote iodine redox reactions by regulating the pore structure and surface chemical properties, thereby improving the specific capacity and cycling stability of the battery. Additionally, we put forward the challenges and issues faced by carbon materials in the practical application of zinc-iodine batteries, including how to further enhance iodine adsorption capability and improve the structural stability of the electrode. Accordingly, several potential future research directions are proposed with a view to further improving the electrochemical performance and reducing the manufacturing cost, thus laying the foundation for advancing the development and application of this emerging battery technology.
Contents
1 Introduction
1.1 Research background and significance of zinc-iodine batteries
1.2 The importance of carbon materials in zinc-iodine batteries
2 Overview of zinc-iodine batteries
2.1 Reaction mechanism of zinc-iodine batteries
2.2 Advantages and problems of zinc-iodine batteries
3 The application of carbon materials in the cathode of zinc-iodine batteries
3.1 Carbon nanotube-based cathodes
3.2 Graphene-based cathodes
3.3 Activated carbon-based cathodes
3.4 Biomass-derived carbon-based cathodes
3.5 Other porous carbon material-based cathodes
4 Conclusions and outlook

Compared to lithium-ion batteries, sodium-ion batteries have greater advantages in terms of resources, cost, safety, power performance, low-temperature performance and so on. However, the energy density of sodium-ion batteries is relatively low. To explore broader application prospects, the development of high specific energy sodium batteries has become a research hotspot in both academia and industry. The anode is considered the key bottleneck constraining the development of the sodium battery industry due to limitations such as the inability of graphite to serve as sodium anodes and the high cost, low Coulombic efficiency, and poor kinetics of mainstream hard carbon materials. In recent years, anode-free sodium batteries (AFSBs) have garnered widespread attention due to their advantages in energy density, process safety, and overall battery cost. However, AFSBs generally show rapid capacity loss owing to the rupture of the solid-electrolyte interphase (SEI) layer, increased chemical side reactions, serious dendrite growth and the formation of dead sodium. As the AFSBs operate, active sodium is continuously consumed without additional metallic sodium to replenish it, leading to poor cycling performance and failure of AFSBs. These issues can be attributed to the following characteristics: the high reactivity of sodium, non-uniform nucleation and huge volume expansion. To elucidates the strategies of promoting dendrite-free growth on the anode side of AFSBs, this review focuses on the current collector-sodium interface and sodium-electrolyte interface, including the design of sodiophilic coatings, porous skeleton structure to regulate the sodium nucleation process, and the construction of robust SEI interface, which further guides the homogeneous sodium deposition and stripping process. This comprehensive review is expected to draw more attention to anode-free configurations and bring new inspiration to the design of high specific energy batteries.

Contents

1 Introduction

2 Factors affecting sodium deposition on the anode side

2.1 High reactivity of sodium

2.2 Inhomogeneous sodium deposition

2.3 Volumetric deformations

3 Critical differences between sodium and lithium

4 Interface design principles and strategies

4.1 Design principles

4.2 Homogeneous nucleation regulation at the current collector-sodium interface

4.3 Formation of robust SEI at the sodium-electrolyte interface

5 Conclusions and prospects

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.

The control of NO_x is very important for the air quality improvement. Selective catalytic reduction of NO_x by hydrogen (H₂-SCR) has attracted much attention as an efficient and environmentally benign deNO_x technology. In this review we have summarized the research development in the H₂-SCR of NO_x over noble metal catalysts. The typical H₂-SCR reaction mechanisms are introduced first. Then the factors affecting the H₂-SCR performance of noble metal catalysts, such as the active metal, support type, the added promoter and the nature of active metal, and the structure-activity relationship have been discussed. Finally, the challenges and the prospects for future development of H₂-SCR catalyst are proposed.

Metal-organic frameworks (MOFs) are a kind of porous coordination polymers formed by the assembly of metal ions and organic ligands, exhibit excellent advantages as a nanocarrier, such as easy modification, high drug loading as well as controllable drug release. The diversities of metal ions and organic ligands lead to the diversities of MOFs, which make them wide application in many fields such as storage and separation, catalysis, sensing, biomedical application and others. With high porosity, versatile MOFs allow for the facile encapsulation of various therapeutic agents with exceptionally high payloads. Especially when the particle size of MOFs is controlled down to the nanometer level, named nanoscale metal-organic frameworks (NMOFs), they exhibit a series of structural advantages. Based on the above advantages, NMOFs exhibit excellent application prospects for drug delivery and cancer therapy. NMOFs can be used as therapeutic agents, as well as nanocarriers of drug, photothermal agents, photosensitizers and Fenton reaction catalysis to using passive targeting, active targeting, physicochemical targeting, or combination of the three. The review focuses on the application of chemotherapy (CT), photothermal therapy (PTT), photodynamic therapy (PDT), chemodynamic therapy (CDT) and various combination therapies. Finally, we will elaborate the current challenges and future development prospects of NMOFs in cancer application.

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.