Abbreviation (ISO4): Prog Chem
Editor in chief: Jincai ZHAO
Metal nanoclusters， with their atomically precise structures， unique quantum effects， and tunable optoelectronic properties， have emerged as a crucial bridge connecting discrete metal atoms and bulk metals. As a pivotal material for next-generation high-performance optoelectronic devices， in-depth understanding of their structure-property relationship is necessary for the on-demand design of functional devices. However， conventional characterization techniques predominantly focus on the macroscopic effects induced by collective behaviors of cluster ensembles， making it difficult to precisely resolve the structure-performance relationship of metal nanoclusters at the atomic level， significantly hindering the advancement of metal nanoclusters in atomically precise fabrication and functional integration. With continuous progress of single-molecule electronics， single-cluster devices have emerged as an effective platform for directly revealing the intrinsic electronic structure and quantum transport behavior of metal nanomaterials at the single-cluster scale， largely bypassing the ambiguity in structure-performance relationship caused by averaging effects and structure heterogeneity of cluster ensembles. This review focuses on the single-cluster devices research， systematically summarizing recent progress in precise synthesis of functionalized clusters， fabrication of single-cluster devices， electrical transport behavior of single-cluster devices， and their potential applications in diverse fields. We then conclude our discussion with key challenges and perspectives for the future development of single-cluster devices， aiming at offering an useful reference for design and fabrication of nanodevices at the atomic level.
1 Introduction
2 Precise synthesis of functionalized metal nanoclusters
2.1 Metal core doping
2.2 Ligand engineering
3 Fabrication of single cluster devices
3.1 Static single-cluster devices-electromigration technique
3.2 Dynamic single-cluster devices
4 Electrical transport properties of single-cluster devices
4.1 Regulation of electrical transport properties of single-cluster junctions at the cluster-electrode interface
4.2 Regulation of electrical transport properties of single-cluster junctions by the intrinsic structure of clusters
5 Applications of single-cluster devices
5.1 Single-cluster switch devices
5.2 Single-cluster transistor devices
5.3 Catalytic characterization platform based on single cluster devices
5.4 Single-cluster light-emitting diode devices
6 Conclusion and outlook
Photocatalytic water splitting for hydrogen production is recognized as one of the most promising solutions to alleviate global energy crises and mitigate environmental pollution. As a typical ternary chalcogenide semiconductor with a layered structure， Zn3In2S6 （ZIS） has garnered significant attention in the field of photocatalytic hydrogen evolution， thanks to its favorable energy band structure， excellent visible-light response capability， and abundant surface active sites. This review comprehensively summarizes the latest research progress of ZIS-based nanomaterials in photocatalytic hydrogen production. First， it systematically elaborates on the fundamental properties of ZIS， including its hexagonal layered crystal structure and its energy band characteristics， as well as the core mechanism of photocatalytic hydrogen production centered on the separation and migration of photogenerated carriers. Then， the review focuses on the application progress of ZIS-based nanomaterials in different photocatalytic hydrogen production systems： overall water splitting （achieving efficient carrier separation via S-scheme heterojunctions）， hydrogen production in sacrificial agent systems （optimizing hole consumption paths with agents like lactic acid， formic acid， and triethanolamine to enhance efficiency）， and bifunctional coupled reaction systems （including organic pollutant degradation coupled with hydrogen production， selective oxidation of alcohols such as benzyl alcohol and 5-hydroxymethylfurfural coupled with hydrogen production， and hydrogen peroxide synthesis coupled with hydrogen production）. For each system， a comparative analysis is conducted on reaction mechanisms， advantages， disadvantages， performance optimization strategies （e.g.， heterojunction construction， cocatalyst loading， defect engineering）， and technical economy. Finally， the review discusses the current challenges faced by ZIS-based photocatalytic materials， especially in bifunctional coupled reaction systems， such as limited selectivity in organic oxidation， catalyst deactivation， and complex product separation， and proposes future development directions， including the design of atomically dispersed cocatalysts， in situ mechanism studies using advanced characterization technologies， and integration with practical application scenarios like wastewater treatment. This review provides a systematic reference for the rational design and further development of high-performance ZIS-based photocatalytic materials for hydrogen production.
1 Introduction
2 Structure and properties of ZIS-based nanomaterials
2.1 Crystal structure
2.2 Optical properties and energy band structure
3 Mechanism of photocatalytic hydrogen production
4 Research progress on photocatalytic hydrogen production by ZIS-based nanomaterials
4.1 Overall water splitting for hydrogen production by ZIS
4.2 Photocatalytic hydrogen production in sacrificial agents systems
4.3 Photocatalytic degradation of organic pollutants coupled with hydrogen production
4.4 Photocatalytic selective oxidation of BA/biomass alcohols coupled with hydrogen production
4.5 Photocatalytic hydrogen production coupled with hydrogen peroxide synthesis
5 Conclusions， future outlook， and challenges
5.1 Conclusions
5.2 Future outlook and challenges
This article reviews the challenges and recent advancements in the utilization of methane （CH4） resources via low-temperature electrochemical oxidation （CH4OR） for producing value-added chemicals. Conventional indirect pathways， including methane reforming， are energy-intensive and operate under harsh conditions. In contrast， thermal catalytic partial oxidation frequently results in over-oxidation， thereby limiting its practical applications. In contrast， electrochemical CH4OR represents a promising alternative， facilitating efficient methane conversion under mild conditions， compatible with renewable energy sources， and providing advantages in product separation and transport. This review explores the mechanistic aspects of C—H bond activation during CH4OR， encompassing both direct and radical-mediated indirect pathways.
1 Introduction
2 The mechanism of low-temperature electrooxidation of methane
2.1 Direct activation mechanism of methane dehydrogenation
2.2 Mechanism of methane dehydrogenation activated by reactive oxygen species
2.3 Kinetic and thermodynamic control in the CH4OR
3 Methane electrooxidation catalyst
3.1 Noble metal catalysts
3.2 Alloy catalysts
3.3 Transition metal oxide catalysts
3.4 MOFs catalysts
3.5 Single atom catalysts
4 Defect engineering： material design strategy for catalytic performance optimization
5 Conclusions and prospects
Metal-support interactions （MSIs） strategy play a critical role in designing and optimizing water-splitting catalysts. This review constructs a comprehensive framework for MSIs research， spanning from theoretical foundations to water-splitting applications. The fundamental concepts and historical evolution of MSIs are clarified， together with a taxonomic classification based on their physicochemical nature. On this basis， it delves into the formation mechanisms of various MSIs and systematically summarizes advanced characterization techniques used to analyze their electronic structures and interfacial properties. This review further explores how support properties， metal morphology， and preparation conditions collectively determine the strength and interaction mode of MSIs. A dedicated section introduces enhancement strategies， summarizing recent approaches for strengthening MSIs effects through defect engineering， interfacial design， and dynamic regulation. The applications of MSIs regulation in hydrogen evolution reaction （HER）， oxygen evolution reaction （OER）， and overall water splitting systems （OWS） are comprehensively discussed， along with the corresponding activity-enhancement mechanisms. It also outlines the challenges and future development directions in this field concerning atom-level precision control， operational condition characterization， and large-scale application.
1 Introduction
2 The formation and classification of MSIs
2.1 The formation of MSIs
2.2 The classification of MSIs
3 Characterization of MSIs
3.1 XANES
3.2 AC-TEM
3.3 Density functional theory of MSIs
3.4 Others
4 The formation and influencing factors of MSIs
4.1 Support
4.2 Metal
4.3 Interface temperature effect
5 Application of MSIs in HER and OER
5.1 HER
5.2 OER
6 Summary and outlook
6.1 Summary
6.2 Outlook
Lithium-air batteries are considered a strong candidate for next-generation electrochemical energy storage due to their exceptionally high theoretical energy density. However， the inherent issues of liquid electrolytes， such as flammability and uncontrolled lithium dendrite growth， severely restrict the safety and practical application of lithium-air batteries. Therefore， developing polymer electrolytes that combine high safety， good mechanical properties， and favorable interfacial compatibility is a critical path toward realizing practical solid-state lithium-air batteries. This review summarizes the fundamental characteristics， preparation methods， and performance in LABs of three categories of polymer electrolytes： solid polymer electrolytes， gel polymer electrolytes， and composite polymer electrolytes. A particular emphasis is placed on reviewing the roles and mechanisms of active and inert fillers in improving the polymer-filler interface， enhancing ion transport and mechanical strength， and reinforcing interfacial stability. The review concludes by summarizing the major current challenges and proposing future research directions， aiming to promote the system integration and engineering application of solid-state lithium-air batteries toward achieving high energy density and long cycle life.
1 Introduction
2 Solid polymer electrolytes for Li-air batteries
2.1 Polyethylene oxide
2.2 Polyvinylidene fluoride-co-hexafluoropropylene
2.3 Other polymers
3 Gel polymer electrolytes for Li-air batteries
4 Composite polymer electrolytes for Li-air batteries
4.1 Active filler
4.2 Inert filler
5 Conclusion and outlook
Flexible mechanical sensors （FMSs） show significant promise for applications including health monitoring， human motion tracking， electronic skin， and human-machine interaction， and have thus emerged as a key research area within flexible electronics and wearable technology. Hydrogels， with their outstanding stretchability， flexibility， and biocompatibility， offer conformal contact with tissues or skin for stable signal acquisition， making them a prime candidate for constructing FMSs. In recent years， the incorporation of different conductive materials has led to the development of various conductive hydrogels， thereby advancing multifunctional FMSs. This review summarizes recent progress in conductive hydrogel-based FMSs （CHFMSs）， with a focus on constituent materials （e.g.， conductive nanofillers， ionic additives， or conductive polymers）， performance characteristics， and conductive mechanisms. A classification of FMSs based on the conduction mechanisms （resistive， capacitive， piezoelectric， and triboelectric） is also provided. Furthermore， the potential applications of FMSs in various practical scenarios are discussed. Finally， the key challenges and prospects in the developing field are outlined.
1 Introduction
2 Types of CHs
2.1 Nanocomposite-based CHs
2.2 Ionic-based CHs
2.3 Conductive polymer-based CHs
2.4 Hybrid CHs
2.5 Analysis of different types of CHs
3 Classification and performance of CHFMSs
3.1 Classification of CHFMSs
3.2 Multimodal sensing based on CHFMSs
3.3 Performance of CHFMSs
3.4 Interfacial engineering for CHFMSs
4 Application of conductive CHFMSs
4.1 Healthcare monitoring
4.2 Human motion monitoring
4.3 Human-machine interaction
5 Challenges and prospects
Accurate and real-time sensing is fundamental to advancements in health diagnostics， environmental monitoring， and industrial safety. However， conventional sensing materials such as metal oxides， conducting polymers， and carbon-based composites are constrained by intrinsic trade-offs between sensitivity， selectivity， and operational stability. To address these limitations， metal-organic frameworks （MOFs） have emerged as a transformative class of materials， offering unparalleled structural tunability， ultrahigh surface areas， and programmable pore chemistry. This comprehensive review provides an in-depth analysis of MOF-based chemiresistive sensors， moving beyond a simple catalog of examples to establish a mechanistic understanding of how molecular-level design dictates sensing performance. We systematically deconstruct the evolution from often-insulating pristine MOFs to advanced composites where MOFs synergize with conductive fillers like graphene， carbon nanotubes， and polymers and to MOF-derived porous carbons and metal oxides. Each category is critically examined to highlight strategies for overcoming inherent challenges in electrical conductivity， response kinetics， and long-term stability. The review is structured to guide the researcher in the field from fundamental design principles and charge transport mechanisms to performance benchmarking against key metrics such as sensitivity， limit of detection， selectivity， and response/recovery times. A significant focus is placed on the integration of MOFs into next-generation applications， including flexible and wearable electronics， multi-parameter sensor arrays， and intelligent systems that leverage artificial intelligence for pattern recognition and drift compensation. Furthermore， we critically address the pivotal challenges hindering practical deployment， such as hydrothermal/chemical stability， mechanical robustness for wearable formats， and the urgent need for standardized testing protocols. By synthesizing insights from fundamental research and cutting-edge applications， this review serves as a rational design guide and a forward-looking perspective， outlining a concrete roadmap for harnessing the full potential of MOFs in the development of intelligent， reliable， and commercially viable next-generation chemiresistive sensing technologies.
1 Introduction
2 Design principles of MOFs
3 MOFs in chemiresistive sensing
3.1 Basic principles
3.2 Pristine MOF-based sensors
3.3 MOF composites and hybrids
3.4 MOF-derived materials
3.5 Challenges in stability and practical deployment
4 Future outlook & emerging applications
4.1 Integration with novel transduction mechanisms and flexible electronics
4.2 The path to intelligent and cognitive sensing systems
4.3 Multi-modal and extreme-performance sensing
4.4 The path to commercialization
5 Conclusion and future perspectives
Photoelectrochemical （PEC） biosensors， as an emerging analytical platform， offer significant advantages， including low background signals， high sensitivity， and operational simplicity， due to the inherent separation of the excitation source and the detection signal. The core of achieving high performance in PEC biosensors lies in the development of efficient signal amplification strategies. This review systematically summarizes recent research progress on signal amplification mechanisms in PEC biosensors. Photoelectric †conversion constitutes the basis of PEC sensing， primarily involving three essential processes： light harvesting， charge carrier separation， and interfacial reaction. Based on this， the prevailing signal amplification mechanisms are reviewed from the core processes of photoelectric conversion to the design of signal output. Simultaneously， the design principles and characteristics of these mechanisms are delved. Finally， this review examines the challenges of PEC sensing technologies and explores future trends. This review aims to provide theoretical guidance for the rational design of high-performance PEC biosensors and to promote their further development in applications of analysis.
1 Introduction
2 Signal amplification mechanisms in PEC sensors
2.1 Modulating light absorption and photogenerated charge carriers separation
2.2 Modulating interfacial redox reactions
2.3 Modulating the output signal
3 Challenges and perspectives
Agricultural activities constitute a significant source of greenhouse gases including methane （CH4）， nitrous oxide （N2O）， and carbon dioxide （CO2）. Achieving continuous， real-time， and large-scale online monitoring of these gases represents a crucial means of advancing sustainable agriculture and addressing climate change. Although monitoring technologies such as infrared spectroscopy and electrochemical sensing have demonstrated mature performance in terms of accuracy and selectivity， their high cost， energy consumption， and complex deployment methods have limited widespread adoption in agricultural settings. This review highlights that semiconductor gas sensors， with their advantages of low cost， ease of integration， suitability for large-scale deployment， and deep integration with the Internet of things， are emerging as the ideal core technology for constructing future agricultural monitoring networks. The paper systematically reviews recent research advances inenhancing semiconductor sensor sensitivity， selectivity， and stability through strategies including nanomaterial regulation， heterostructure construction， catalytic and surface engineering， and signal processing algorithm integration. It also delves into practical challenges encountered in real agricultural environments—such as environmental interference， humidity effects， cross-sensitivity， and long-term stability—within livestock management and soil monitoring applications. Finally， this paper outlines future development trends for semiconductor gas sensors in agriculture： intelligent design of sensing materials， high integration of sensing nodes with IoT， multi-gas collaborative monitoring， and AI-based gas identification and emission modelling. Collectively， these advancements will drive the formation of future smart agricultural systems integrating precise monitoring， intelligent decision-making， and ecological management.
1 Introduction
2 Greenhouse gas detection technologies
2.1 Benchmark monitoring technologies
2.2 Semiconductor gas sensors
2.3 Comparison of technical pathways and evolutionary trends
3 Agricultural application scenarios
3.1 Livestock management
3.2 Soil and crop management
3.3 Greenhouse gas monitoring and control
4 Technical challenges and resolution pathways
4.1 Environmental interference
4.2 Long-term stability and power consumption
5 Outlook for sustainable integrated agriculture
5.1 Intelligent sensing and network architecture
5.2 Implementation of management closed-loop systems and comprehensive benefit assessment
Carbon dots （CDs）， as an emerging class of zero-dimensional carbon nanomaterials， have demonstrated significant potential in the field of biomedical imaging due to their unique photoluminescence properties， excellent biocompatibility， and low toxicity. This review systematically summarizes the recent progress in the application of CDs as dual-modal or multimodal probes in computed tomography （CT）， magnetic resonance imaging （MRI）， and fluorescence imaging （FL）. It particularly focuses on the synergistic effects of metal ion and heteroatom doping on the physicochemical properties of CDs， with an emphasis on their optical， magnetic， and X-ray attenuation characteristics. The findings reveal that element doping and surface functionalization can significantly enhance the performance of multimodal imaging. For instance， doping with metal ions or heteroatoms can effectively improve the relaxivity in MRI/FL dual-modal imaging and optimize the X-ray attenuation properties in CT/FL dual-modal imaging. Furthermore， some CD-based nanomaterials have successfully achieved MRI/CT/FL trimodal imaging， providing innovative solutions for precision medicine. Despite the progress made， CDs-based multimodal probes still face several challenges， including the imbalance in multimodal performance and the lack of comprehensive long-term biosafety assessments. For future clinical translation， further optimization of material design and the implementation of standardized toxicological evaluations will be essential. These efforts will significantly advance the diagnosis and treatment of diseases.
1 Introduction
2 Classification and synthesis of doped CDs
2.1 Solvothermal method
2.2 Microwave method
2.3 Pyrolysis method
2.4 Other methods
3 Properties of doped CDs
3.1 Optical properties
3.2 Biocompatibility
3.3 Magnetic properties
3.4 X-ray attenuation properties
4 Advances in multimodal imaging applications
4.1 Doped CDs for CT/FL imaging
4.2 Doped CDs for MRI/FL imaging
4.3 Doped CDs for MRI/CT/FL imaging
4.4 The potential of multimodal imaging for clinical applications
5 Conclusion
Self-enhanced electrochemiluminescence （SEECL）， as an emerging analytical technique， significantly enhances electrochemiluminescence （ECL） efficiency by integrating luminophores and co-reactants into unified nanostructures or molecular frameworks， demonstrating substantial value in the fields of bioanalysis and environmental sensing. Based on the integration mode of luminophores and co-reactants， SEECL structures can be categorized into two types： covalently bonded SEECL and non-covalently bonded SEECL. Covalently bonded SEECL can be further divided into inorganic， organic， and nanoscale covalent bonding SEECL systems， while non-covalently bonded SEECL includes structures such as nanocarrier encapsulation， self-assembly， and metal-organic framework （MOF）-based SEECL. On the basis of summarizing the construction principle of SEECL， this paper summarizes its applications in areas including bioanalysis （protein biomarker detection， nucleic acid analysis， and enzyme activity monitoring）， environmental sensing （trace detection of heavy metal ions and organic pollutants）， food safety testing， wearable devices， and point-of-care testing （POCT）. Additionally， the article addresses unresolved issues such as the stability， biocompatibility of SEECL materials and interference from complex matrices， and prospects its future development directions， providing a reference for subsequent research on SEECL.
1 Introduction
2 Construction of SEECL systems
2.1 Mechanistic insights into SEECL
2.2 Covalent-bonded SEECL systems
2.3 Non-covalent-bonded SEECL Systems
3 Applications of SEECL
3.1 Bioanalysis
3.2 Environmental sensing
3.3 Other categories
4 Conclusions and prospects
ISSN 1005-281X (Print)
Started from 1989
Published by: Chinese Academy of Sciences (CAS) and the National Natural Science Foundation of China (NSFC)
