Controllable synthesis of horizontally aligned single walled carbon nanotubes (SWNTs) with specific chirality and high areal density remains a challenge.A recent breakthrough was achieved by the Jin Zhang's group from Peking University.They proposed a feasible route towards tuning the chirality of epitaxially-grown aligned SWNTs according to the designed catalyst lattice symmetry.With different uniform metal carbide catalysts,two different types of aligned SWNTs with specific structures, the metallic (12,6) and semiconducting (8,4) ones,can be synthesized separately with their chiral selectivity both over 80%,tandem with a high density of more than 10 tubes/μm.These exciting results clearly demonstrate that it is possible to control SWNTs'structures based on the symmetry matching in structures between SWNTs and crystal surface of catalyst particles.

Resources and energy are in desperate shortage nowadays, how to improve traditional adsorbents and develop new composite adsorbents with high efficiency, low cost and excellent ability has become a major research topic. Graphene/organic composite adsorbent combines the advantages of graphene and organic materials, and has bright prospects for applications in water treatment, but few relevant reviews have been published about its designs, composite methods, and applications. Hence, this review concludes the progress of preparations and applications of graphene/organic composite adsorbent, and analyzes its properties and problems which can provide references for future researches of graphene/organic composite adsorbents and the future development trends are also outlooked.

Contents
1 Introduction
2 Designs of graphene/organic composite adsorbent
2.1 Graphene matrix
2.2 Organic matrix
2.3 Collective building
3 Classifications of graphene/organic composite adsorbent
3.1 Graphene/small organic adsorbent
3.2 Graphene/synthetic polymer adsorbent
3.3 Graphene/natural polymer adsorbent
3.4 Graphene/multicomponent organic adsorbent
4 Excellent properties of graphene/organic composite adsorbent
4.1 Mechanics
4.2 Macroscopic property
4.3 Adsorption ability
4.4 Stability in aqueous phase
4.5 Biocompatibility
4.6 Other properties
5 Applications of graphene/organic composite adsorbent in water treatment
5.1 Heavy metals
5.2 Dyes
5.3 Antibiotics
5.4 Oils
6 Conclusion and outlook

With the ever-increasing environment problems and insufficient fossil energy, the development of high specific energy secondary battery systems is particularly important. Owing to their overwhelming advantages of high theoretical energy density and low environmental impact, lithium-sulfur batteries are considered as ones of the most promising next generation electrochemical energy storage devices. However, due to the insulating property of sulfur and the shuttle effect associated with the dissolution of the intermediate polysulfides, the practical application of lithium-sulfur battery is facing many challenges. To overcome the limited physical forces of the conventional carbonaceous hosts on sulfur electrode stabilization, the recent applications of host materials with strong chemical bondings to polysulfides have significantly enhanced the comprehensive performance of the composite sulfur electrode, and provide new ideas for the cathode designing of lithium-sulfur batteries. This review summarizes the application of various host materials with specific chemisorption properties and elaborates the function mechanisms between the high efficient host materials and polysulfide intermediates, such as metal oxide and modified carbonaceous materials based on a polar-polar interaction with polysulfides, functionalized organic polymers that rely on sulfurization to anchor sulfur/polysulfides, and metal organic framworks that exhibit Lewis acid-base interactions with polysulfides. This review prospects the development of the lithium-sulfur battery as well.

Contents
1 Introduction
2 The mechanism of chemical bonding between hosts and polysulfide
3 Chemical bonding host materials
3.1 Metal oxide hosts
3.2 Graphene oxide, functionalized graphene hosts
3.3 Element-doped carbon hosts
3.4 Functionalized organic polymer hosts
3.5 Metal organic frameworks hosts
4 Conclusion

The chiral norbornene derivatives as one of the C5 main fractions are the important high value-added derivatives of bis(cyclopentadiene), which are derived from cyclopentadiene and asymmetric dienophile via the Diels-Alder reaction. In this paper, based on the mechanism of reaction, the yield and stereoselectivity of the chiral norbornene ester derivatives, aldehydes derivatives, ketone derivatives and acyl oxazolidinone derivatives are reviewed in the presence/absence of catalyst. Generally, the chiral catalysts such as chiral diols, diphenols or oxazolines coordinated with aluminum, boron, copper, titanium or lanthanide metal complexes promote the synthetic rate, stereoselectivity and enantioselectivity of the chiral norbornene derivatives. Meanwhile, the recent applications of chiral norbornene derivatives are briefly reviewed from two aspects: one is the photochromic materials and the other one is the ion exchange membranes, including anion, cation and composite ion exchange membrane. Finally, the future research and applications of the chiral norbornene derivatives are prospected.

Contents
1 Introduction
2 Synthetic mechanism
3 Preparation of chiral norbornene derivatives
3.1 Chiral norbornene ester derivatives
3.2 Chiral norbornene aldehydes derivatives
3.3 Chiral norbornene ketone derivatives
3.4 Chiral norbornene acyl oxazolidinone derivatives
4 Applications of chiral norbornene derivatives
4.1 Optical materials
4.2 Ion exchange membranes
5 Conclusion

In recent years, phase-selective organogelators (PSOGs) have attracted great attention as a new type of oil-scavenging materials for oil-water separation, because of their excellent properties, such as easy synthesis, low cost, and aqua-safety. These PSOGs could self-assemble via non-covalent forces into 3D fibrous networks, able to selectively capture and gel organic oil phase from an oil-water biphasic mixture. The formed gel floats on the water, allowing an easy separation from water through a simple filtration, thereby greatly eliminating potential environmental pollutions caused by spilled oil. As such, PSOGs might offer a promising solution to oil spill treatment. Despite of their great potential in oil spill treatment, PSOGs with desired properties are very difficult to develop. How to achieve efficient gelation of oils of widely ranging viscosities is one of the most important problems facing the development of PSOGs, which is also a prerequisite for their application in cleaning up actual oil spills. This review mainly summarizes the self-assembly strategies and applications of some selected PSOGs in an oil-water biphasic system, and presents the future developments of the field.

Contents
1 Introduction
2 Amino acid-based PSOGs
3 Sugar-based PSOGs
4 Acid and alkali PSOGs
5 Other types of PSOGs
6 Conclusion

π complexation techniques show the advantages of low energy consumption, high efficiency, and reproducibility, etc. Thus, the π complexation techniques have been widely used in the fields of fuel desulfurization, olefin/paraffin separation, and CO separation from gas mixtures. Adsorbents are the key factors to the π complexation techniques. This review focuses on the synthesis methods and application efficiency of the π complexation adsorbents, and summarizes some important advances both at home and abroad. In general, the universal methods to synthesize the π complexation adsorbents are introduction of transition metal ions (Cu(Ⅰ), Ag(Ⅰ), and Pd(Ⅱ), etc.) into the supports with high surface areas. So far, methods on preparation of π complexation adsorbents based on inorganic molecular sieves have been very detailed, including ion exchange, impregnation method, solid-state grinding, and space confining etc. In this respect, researchers have carried out a large amount of studies. Moreover, the adsorbents show high efficiency. Recently, researchers devote to preparation of π complexation adsorbents based on metal-organic frameworks (MOFs), including undecorated and decorated MOFs. This route has good prospects in research and application fields. In addition, this review summarizes the advantages and disadvantages of several π complexation adsorbents, and gives prospects for the future development trends.

Contents
1 Introduction
2 Preparation of π complexation adsorbents based on inorganic molecular sieves
2.1 Ion exchange method
2.2 Impregnation method
2.3 Solid-state grinding method
2.4 Space confining method
3 Preparation of π complexation adsorbents based on metal-organic frameworks (MOFs)
3.1 In situ π complexation adsorption sites
3.2 Construction of π complexation adsorption sites
4 Preparation of π complexation adsorbents based on other porous materials
5 Chemical theories of π complexation adsorption
6 Other applications of complexation effect
7 Conclusion and outlook

Graphene oxide (GO) and graphene quantum dots (GQDs) are difficult to disperse in the polymer homogeneously. Pickering emulsion polymerization can effectively improve the dispersity of GO and GQDs in the polymer matrix, so the performances of composite material are improved. This article summarizes the preparation and structure of GO and GQDs, and expounds the influence of the GO size, ionic strength, pH, GO and GQDs structure designing, monomer polarity and other factors for the adjustment of amphiphilicity of GO and GQDs as well as the Pickering emulsion polymerization. The research progress of GO and GQDs used for improving the function of composite by Pickering emulsion polymerization is summarized. The ability for GO and GQDs to act as stabilizer for Pickering emulsions is related to the interfacial tension of liquid-liquid interfaces and liquid-solid interfaces and whether GO and GQDs can be adsorbed onto the liquid-liquid interfaces thermodynamically. All of the size, ionic strength, pH and structure designing have an effect on the liquid-solid interfacial tension. Hence, monomer polarity can decide the liquid-liquid and liquid-solid interfacial tension. The GO and GQDs can be modified by modification, reduction and other chemical methods, which can endow the polymer with excellent properties such as conductivity, thermal conductivity and magnetic responsivity. At last, the propects of GO and GQDs stabilizing Pickering emulsion are proposed.

Contents
1 Introduction
2 Graphene oxide
2.1 The preparation of GO
2.2 The structure of GO
2.3 Research progress of GO as Pickering emulsion stabilizer
3 Graphene quantum dots
3.1 The preparation of GQDs
3.2 The structure of GQDs
3.3 Research progress of GQDs as Pickering emulsion stabilizer
4 Conclusion

Hydrogel is cross-linked polymeric network containing more than 90% water. They have been extensively applied in organ reconstruction, soft tissue prosthesis,cell culturing substrate, and controlled drug release. In addition to their good biocompatibility, they share remarkable resemblance to the structures of many living organisms’ tissues, such as muscles, cartilages, corneas and the skin; one key property of hydrogel is that it can be easily integrated with other functional materials to play a synergistic role, which greatly extends the application in many areas. For instance, the hydrogel containing magnetic nanoparticles can take other special effects besides the role of tissue prosthesis in postoperative organ reconstruction after excision of tumor. Thus, they are more suitable for materials of living tissues than any other artificial ones. However, compared with the biological soft tissue, conventional synthetic hydrogels show isotropic structure at the molecular and macroscopic level, lacking ordered structures, which leads to limitations in practical applications. The synthesis of anisotropic hydrogels, to some degree, solves this problem. In this paper, we mainly focus on the preparation methods of anisotropic hydrogels and the classifications of anisotropic properties. The factors influencing the anisotropy are summarized.The existing problems and further research directions are also discussed.

Contents
1 Introduction
2 The property of the anisotropic hydrogel
2.1 Magnetic property of anisotropic hydrogel
2.2 Mechanical property of anisotropic hydrogel
2.3 Optical property of anisotropic hydrogel
2.4 Swelling property of anisotropic hydrogel
3 The preparation of anisotropic hydrogel
3.1 Anisotropic hydrogel synthesized by template method
3.2 Anisotropic hydrogel synthesized by magnetic field
3.3 Anisotropic hydrogel synthesized by self-assembly
4 Conclusion

Paper spray ionization mass spectrometry (PSI-MS) is a new technology of mass spectrometry. This method uses low-cost paper as the carrier, and solid or liquid sample is added to a triangular paper substrate. Through the application of high voltage, the target molecules in the high voltage electric field are driven to reach the paper tip, then a charged spray for PSI-MS is generated. This technology combines the characteristics of ambient mass spectrometry (AMS) and electrospray ionization (ESI) technology, and can analyze sample or substance attached to the sample surface in an open atmospheric environment. It has many advantages such as low cost, high throughput, simple, real-time and fast, and it can also simplify the work processes, improving the usability of mass spectrometry equipment. Herein, a general overview of PSI-MS is given in this paper, including the principle, influencing factors (paper substrate, spray solution, elution mode, and internal standard), the improvement and development of the technology, and corresponding applications in various fields (i.e. biological samples, phytochemistry, variety identification, food safety, and environmental analysis) in recent years. Characteristics and advantages of this technology are introduced in details. A number of studies have proved that PSI-MS is a widely used analytical technique with great prospects. Finally, the shortcomings of PSI-MS in terms of accurate quantification, carrier selection and field analysis are discussed, and some ideas for its improvement are put forward.

Contents
1 Introduction
2 Principle of PSI-MS
3 Influencing Factors
3.1 Paper substrate
3.2 Spray solution
3.3 Elution mode
3.4 Other factors
4 Modification of PSI-MS
4.1 Paper modification
4.2 Improvement of solvent supply
4.3 Improvement of sampling
4.4 PSI-MS combined with other technologies
4.5 Derivation of PSI-MS
5 Application of PSI-MS
5.1 Analysis of biological samples
5.2 Analysis of phytochemistry
5.3 Variety identification
5.4 Food safety
5.5 Environmental analysis
6 Conclusion and outlook

Owing to the unique luminescence phenomenon and the super long afterglow life, the persistent luminescence nanomaterials (PLNPs) can achieve in vitro excitation and the spectral emission regions can be regulated into the “biological transparent window”, which were widely used in optics sensor detection and bioimaging field of disease targeted diagnosis and treatment. In recent years, the syntheses and applications of PLNPs nanoprobe have attracted great attention in the areas of spectroscopy, photonics, photochemistry and materials science. This paper reviews the synthesis methods and surface modification of PLNPs molecular nanoprobe as well as their application in detection and bioimaging in vivo and in vitro. This paper focused on Mn²⁺ and Cr³⁺ doped nanostructures, particularly gallogermanates which are able to give intense red-near infrared persistent emission with a longer afterglow lifetime for more than two weeks and therefore are suitable for bioimaging application. The functionalized red-near infrared persistent luminescence nanomaterials provide a promising technology platform for long-term real-time detection of physiological processes and disease diagnosis in vivo. Finally, the challenges of PLNPs are described.

Contents
1 Introduction
2 Synthesis methods of PLNPs
2.1 Solid-State reaction
2.2 Sol-Gel method
2.3 Hydrothermal method
2.4 Co-Precipitation
2.5 Template method
2.6 Combustion method
2.7 Other methods
3 Application of PLNPs Nanoprobes in biomedicine
3.1 PLNPs based Biosensing and detection
3.2 PLNPs based Bioimaging
3.3 Multimodal Imaging of PLNPs
4 Conclusion and outlook

Recently, the attention to sodium-ion batteries (SIBs) has been aroused on the next generation energy storage systems applications, due to their specific advantages. However, the development of SIBs remains significant challenges. Owing to their open frameworks and porous channels for Na⁺ fast migration, the Prussian blue analogues (PBs) materials can effectively improve the electrochemical performance of SIBs. Herein, we summarize the recent advances and applications of PBs materials for SIBs in terms of preparation process, electronic mechanism and modification technology. The effects of migration ions, transition metals, bound water and vacancy on the electrochemical performance of SIBs are particularly introduced. Moreover, we summarize the research progress on the PBs-based aqueous SIBs, hybrid batteries and appropriate electrolyte. Further, the current difficulties and future research directions of the PBs-based SIBs are also discussed to give an outlook of the prospect trends and application potentials in energy storage systems.

Contents
1 Introduction
2 Preparation of Prussian blue analogues
2.1 Co-precipitation method
2.2 Hydrothermal method
3 Mechanism study of Prussian blue analogues
3.1 Migration ions
3.2 Transition metals
3.3 Bound water and vacancy
4 Modification of Prussian blue analogues
4.1 Doping
4.2 Coating
5 Aqueous rechargeable sodium-ion battery
6 Other researches
6.1 Metal-sodium hybrid battery
6.2 Electrolyte and separator
6.3 Security studies
7 Conclusion