Hydrogen stored in a chemical form as liquid organic compounds and released in-situ on demand through efficient catalytic processes at low temperature is a highly desirable hydrogen storage and transportation strategy. A recent breakthrough was reported by the Ma group at Peking University and their collaborators. They have developed a novel Pt/α-MoC catalyst with atomically dispersed Pt over α-MoC. The exceptional hydrogen production activity comes from the outstanding ability of α-MoC for water dissociation and the unique synergy between Pt and α-MoC for methanol activation and successive reforming processes.

Judicious utilization of host-guest supramolecular interactions and flexibilities of both the host and guest enables metal-organic frameworks to show abnormal adsorption selectivities for the less polar, more saturated hydrocarbons, which is useful for efficient purification of high-value alkenes such as ethylene and butadiene.

Quantum dots (QDs) have been extensively applied in biological detection, in vivo imaging and optoelectronic devices due to their unique optical properties including broad excitation spectra, tunable and narrow emission spectra, high brightness and excellent resistance to photobleaching. Nevertheless, application of aqueous QDs, especially that of aqueous near-infrared fluorescence QDs, is limited by their relatively weak fluorescence and poor stability. Therefore, the development of new approaches for the enhancement of fluorescence of QDs is urgently needed. In recent years, it has been found that the brightness and photostability of QDs can be favorably enhanced by surface plasmon resulted from the nearby metallic nanostructures, which is termed as metal-enhanced fluorescence (MEF). Thus novel strategies for solving the above problems can be proposed based on MEF from QDs, which can be mainly attributed to the increased excitation rate and the increased radiative rate of the excited QDs. In this review, mechanism of MEF, especially that of MEF related to QDs, is introduced based on the near-field interaction between metallic nanostructures and QDs. Key factors affecting the efficiency of fluorescence emission are reviewed, including the distance between metallic nanostructures and QDs, the type of QDs, the composition, shape, and size of metallic nanostructures, and so forth. Current progresses in the application of MEF from QDs are also summarized. Finally, challenges in the development of MEF from QDs are discussed. We believe that with the rapid development of nanoscience and nanotechnology, MEF from QDs will attract more and more attention and show unique potentials in the near future.
Contents
1 Introduction
2 Mechanism
2.1 Luminescence of QDs
2.2 Metal-enhanced fluorescence from QDs
3 Key factors affecting metal-enhanced fluorescence from QDs
3.1 Distance between metallic nanostructures and QDs
3.2 Composition, shape and size of metallic nanostructures
3.3 Types of QDs
4 Applications
5 Conclusion

Study and development of anti-fouling materials, which can reduce nonspecific adsorption of proteins and attachment and growth of microorganisms, not only largely improve sensitivity of some medical diagnostic equipment, reduce side effects of medical implants, such as inflammation and thrombus, but also can save energy and power that navigation needs. Traditional anti-fouling materials are hydrophilic polymers such as poly(vinyl alcohol), poly(N-vinyl pyrrolidone), poly(2-oxazoline), poly(ethylene glycol) and zwitterionic polymers. Although these materials have good anti-fouling properties, they lack desirable biodegradability as they are based on non-degradable polymer backbones such as poly(acrylic ester) and poly(acrylic amide). Therefore, it is highly desirable to study and develop biodegradable anti-fouling materials. Biodegradable anti-fouling materials can be achieved by introducing anti-fouling functional moieties (hydrophilic polymers or antifoulants) into biodegradable matrixes, such as aliphatic polyesters, aliphatic polycarbonates, polypeptides and polysaccharides. In this review, the progress of biodegradable anti-fouling materials is summarized. Firstly, the harm of biological fouling, the classification, characteristic and existing problem of antifouling materials are introduced. Recent advancement of biodegradable anti-fouling materials is highlighted. The three main mechanism, i.e., spatial exclusion theory, structural similarity theory, and hydration theory, to resist nonspecific adsorption of proteins hydrophilic polymers with different structures (poly(ethylene glycol), zwitterionic polymers, and other hydrophilic polymers) are discussed and compared. The mechanism to resist adsorption of microorganism of anti-foulant is also summed up. Synthesis, structures, properties and their corresponding application fields of of biodegradable anti-fouling materials are critically summarized and commented in detail from hydrophilic polymers with various structures and anti-foulants. Perspective on future research directions of biodegradable anti-fouling materials is also discussed.
Contents
1 Introduction
2 Current research states of biodegradable anti-fouling materials
2.1 Biodegradable anti-fouling materials based on hydrophilic polymers
2.2 Biodegradable anti-fouling materials based on anti-foulants
3 Perspective of biodegradable anti-fouling materials

Graphene is a one-atom-thick planar sheet of sp²-bonded carbon atoms that are densely packed in a two-dimensional crystal. As the building block for various macroscopic membranes, graphene has been known as a rising star in the area of membrane separation. The preparation and application of graphene based separation membrane are discussed in this review. Particular emphasis is directed to the wide application of graphene based membrane in the field of water treatment, gas separation, desalination and so on. Compared to traditional polymer membrane, graphene based separation membrane has the advantage of anti-fouling, high flux and good selectivity. Moreover, the application of other emerging 2D materials such as BN, MoS₂ and WS₂ in separation technology is also discussed. Finally, the future opportunities and challenges for the wide application of graphene based membrane are also discussed along with perspectives for future research in these fields.
Contents
1 Introduction
2 The preparation of graphene based membranes
2.1 Vacuum filtration method
2.2 Spin coating/spraying method
2.3 Layer-by-layer self-assembly method
2.4 Blending method
3 The application of graphene based membranes
3.1 Gas separation
3.2 CO₂ capture
3.3 Water purification
3.4 Desalination
3.5 Isotope removal
4 Membrane modification and performance improvement
4.1 Antifouling properties
4.2 Flux increase
4.3 Balance between the selectivity and flux
5 Separation membranes based on other emerging two-dimensional materials
6 Conclusion

Photocatalytic technology based on semiconductor materials is expected to use clean solar energy to control the environmental pollution and ease the energy shortages.In recent years, some silver-containing semiconductor materials with narrow band gap exhibit excellent oxidation and reduction ability under visible light irradiation, hence, silver-containing photocatalysts have become one of the focuses in the field of photocatalytic materials. Single silver-containing photocatalytic materials have high cost and poor stability, which limit their practical applications. As a result, the composite photocatalytic materials have been widely studied. Recently, simulating the photosynthesis process of green plants, all-solid-state Z-scheme photocatalytic systems are established, which can enhance the stability and reduce the cost of silver-containing photocatalytic materials as well as improve their photocatalytic performances. In this paper, we firstly describes the derivation and reaction mechanism about the all-solid-state Z-scheme photocatalytic systems, and then reviews the construction, application and reaction mechanism of silver-containing semiconductor materials-based all-solid-state Z-scheme photocatalytic systems so far.At last, we point out some existing problems about these silver-containing semiconductor materials-based Z-scheme photocatalytic systems, and their research prospects are also proposed.
Contents
1 Introduction
2 The derivation and reaction mechanism of all-solid-state Z-scheme photocatalytic systems
3 The research findings of silver-containing semiconductor materials-based Z-scheme
photocatalytic systems
3.1 AgX-based Z-scheme photocatalytic systems
3.2 Ag₃PO₄-based Z-scheme photocatalytic systems
3.3 Ag₂CO₃-based Z-scheme photocatalytic systems
3.4 Ag₂MO₄-based Z-scheme photocatalytic system
4 Conclusion

Two-dimensional (2D) perovskites have become a research hotspot as one kind of high-performance optoelectronic devices, attracting a great deal of attention in recent years due to their unique structures and interesting optoelectronic properties. Besides the solution-processable, fiexible and wearable characteristics similar to the conventional 2D materials, these new 2D materials can be assembled into uniform and fiexible ultrathin films with highly oriented microstructures. Also, they have a long charge carrier diffusion lengths, low binding energy, high quantum yield, high crystallinity, broad absorption spectra, high light absorption coefficients, low rates of non-radiative charge recombination inherited from three dimensional perovskites. In this review, we focus on the composition characteristics, structural formation rules, photoelectric properties and nonlinear optical properties of two-dimensional perovskites. Specifically, we classify the preparation methods of two-dimensional perovskites into two main types of the solution method and vapor method. Furthermore, we comprehensively summarize the recent advancements of two-dimensional perovskites in the applications of solar cells, photodetectors, light-emitting diodes, field effect transistors and lasers.We also discuss the current challenges and future research directions to achieve optimal performance for practical applications in detail to provide applicable suggestions in designing high-performance two dimensional perovskites for advanced optoelectronic devices in the future.Contents
1 Introduction
2 Structure and properties of two-dimensional perovskites
2.1 Structure of two-dimensional perovskites
2.2 Formation rule of two-dimensional perovskites
2.3 Optoelectronic properties of two-dimensional perovskites
2.4 Band gap and nonlinear optical properties of two-dimensional perovskites
3 Synthesis of two-dimensional perovskites
3.1 Solution methods
3.2 Vapor methods
4 The applications on optoelectronic devices of two-dimensional perovskites
4.1 Solar cells
4.2 Photodetectors
4.3 Light-emitting diodes
4.4 Field effect transistors
5 Conclusion

As a new type of thin film solar cells, organic and inorganic hybrid perovskite solar cells (PSCs) have rapidly developed since the first PSCs were fabricated by Mayasaka, and the power conversion efficiency is improved from 3% to 22.1%. As light-harvesting materials, the perovskites show excellent photovoltaic performances, such as high absorption coefficient, high carrier mobility, long carrier diffusion lifetime and direct band gap. Nevertheless, the perovskite materials have shown limited effective lifetimes because the perovskite materials are sensitive to water and oxygen. As demonstrated in previous reports, functional additives can adjust structure of perovskite crystal, progress of crystallization or defect of crystal, which can improve the photovoltaic performances or long-term stability of PSCs. The application of functional additives in PSCs is reviewed in detail and predicted.
Contents
1 Introduction
2 Application of functional additives in perovskite solar cells
2.1 Inorganic additives
2.2 Organic additives
3 Conclusion

In recent years, zero-valent aluminum (ZVAl) has been used to remove contaminants in water environment due to its strong reducibility, which is developing into a new water treatment technology. However, ZVAl can be readily oxidized to form a dense oxide layer when exposed to oxygen or water medium, which will decrease the reductive capacity of ZVAl, and become the biggest limiting factor for the further application of this technology. Therefore, it is crucial to understand the surface reaction mechanism of ZVAl in aqueous media comprehensively. Actually, ZVAl has been widely used in the field of hydrogen generation because the reaction between ZVAl and H₂O can generate hydrogen efficiently. In essence, the contaminants removal by ZVAl is the same as the hydrogen generation by Al/H₂O reaction. In both cases, ZVAl reduction reaction occurs, and releases electrons. The primary difference between the case of contaminant removal and the case of hydrogen generation is that their electron transfer targets are pollutants in water and the water itself, respectively. In order to overcome the limitation of surface oxide film, researchers from the two fields take measures to improve the reductive capacity of ZVAl, including film dissolution by acid or alkali, film destruction by mechanical ball milling or alloying, useful film generation by building electron channel, film phase transformation by high-heat treatment, and so on. In addition, the environment conditions of water medium, such as temperature, pressure, trace ions and organic acid in water, and (hydr)oxide added, have a significant effect on the surface change of ZVAl. Therefore, in this review, based on the oxide film's formation, dissolution, destruction, transformation and the impact of its external environment, etc., the latest research progress and the surface reaction mechanism of ZVAl in the fields of contaminant removal and hydrogen generation, are summarized and prospected. It is believed that ZVAl would be applied widely in two fields supposing that the limitations of oxide film are overcomed.
Contents
1 Introduction
2 Formation of surface oxide film
2.1 Formation of surface oxide film in air
2.2 Formation of surface oxide film in water
3 Change the surface oxide film to improve reducibility of ZVAl
3.1 Dissolution of film
3.2 Destruction of film
3.3 Phase transformation of film
3.4 Building electronic channels
4 Influence of water environment conditions on the mechanism of ZVAl surface
4.1 Temperature
4.2 Initial pressure
4.3 Trace ions and organic acid in water
4.4 (Hydr)oxide
5 Conclusion and outlook

With the development of modern electronic products into the direction of miniaturization, integration and flexibility, and the increasing demand for functional, intelligent and wearable textiles, electronic textiles (E-textiles) become a research hotspot. Due to excellent performances such as high specific surface area, thermal conductivity, electrical conductivity, transmittance, ductility, mechanical strength and flexibility, silver nanowires (AgNWs) combined with textiles are one of the ideal methods for preparation of E-textiles, which own the advantages of simple preparation, easy integration, having no adverse effects on wearing comfort, durability, low cost, obtaining antibacterial and anti-UV performance. This paper firstly introduces blending methods and finishing methods in preparing AgNWs conductive textiles. The research progress of AgNWs in thermal textiles, heater textiles, flexible electronic sensors, super-elastic conductive composite fibers and self-powered textiles in recent years is discussed. The existing problems and the future directions are also pointed out in order to provide reference for the future research of AgNWs in E-textiles finally.
Contents
1 Introduction
2 Methods for preparing AgNWs conductive textiles
2.1 Blending methods
2.2 Finishing methods
3 Application
3.1 Thermal textile and heater textiles
3.2 Flexible electronic sensors
3.3 Super-elastic conductive composite fibers
3.4 Self-powered textiles
4 Conclusion

Calibration transfer is a key technique to ensure the consistency of instruments or analytical methods. Near infrared spectra is strongly influenced by the status of instrument or the environment of measurement. Therefore, calibration transfer is essential for practical applications of near infrared spectroscopy. This paper provides an overview of the state-of-the-art pertaining to calibration transfer methods, including those with and without standard samples, and the focus is on the methods based on multivariate calibration, factor analysis, neural network and multi-task learning for algorithms with standard samples and on the methods based on spectral correction, model coefficient correction and robust multivariate calibration for algorithms without standard samples. The formulation and efficiency of different calibration transfer methods are analyzed from the viewpoint of the algorithms. Among the summarized methods, piecewise direct standardization (PDS) and its variants are still the gold standard for calibration transfer, but algorithms based on factor analysis is becoming popular and those based on neural network and multi-task learning has gradually attracted more attention in recent years. In practical applications, however, it is difficult or even impossible to obtain the standard samples for measuring their spectra on both master and slave instruments, calibration transfer without standard samples is more practical. Furthermore, with the development of the instrumentation in miniaturization, imaging and hyper-spectral imaging, calibration transfer will be more and more essential in the future.Contents
1 Introduction
2 Algorithms with standard samples
2.1 Multivariate calibration transfer
2.2 Factor analysis methods
2.3 Neural network
2.4 Multi-task learning
2.5 Others
3 Algorithms without standard samples
3.1 Spectral correction methods
3.2 Model coefficient correction methods
3.3 Robust multivariate calibration
4 Conclusion