Air pollution is a major challenge for the humankind. Under the highly complex air pollution conditions in China, strong homogenous nucleation and multiphase heterogeneous processes coexist, coupling with strong atmospheric oxidizing capacity and ozone pollution. This complex air pollution, different from the “London smog” and the “Los Angeles photochemical smog”, is a new type of “haze chemistry smog” pollution. “Haze chemistry” distinguishes from traditional homogeneous chemistry by surpassing its existing theoretical understandings. It is a type of air pollution chemistry that comprehensively studies the gas-liquid-solid multiphase processes, revealing the formation mechanism of PM_2.5 and the non-linear relationship between PM_2.5 and O₃ under typical multi-medium complex air pollution conditions. Understanding “haze chemistry” processes is crucial for precise control of complex air pollution in China and other countries. Here, we propose and summarize the concept of “haze chemistry”, and discuss its further improvement, development, and application.

CRISPR (Clustered regularly interspaced short palindromic repeats) technology is a revolutionary gene editing tool developed in recent years, which has quickly become a cutting-edge technology in the field of biology and medicine and widely used in gene function research and gene therapy. In addition to excellent gene editing capabilities, various new functions are also being continuously created with the efforts of scientists from different fields. CRISPR has excellent sequence recognition properties, nucleic acid cleavage ability, and is easy to program and design. Therefore, it exhibits unique charm in the field of bioanalytical chemistry, and has made breakthrough progress in virus detection, clinical diagnosis, and single cell imaging analysis. At present, there are many types of detection methods using CRISPR technology. Therefore, we summarize and classify the current research status of CRISPR analysis and detection methods, and look forward to its development trend.

Aggregation of β-amyloid (Aβ) has been considered as an important factor leading to Alzheimer’s disease (AD). Previous studies have focused on the full-length unmodified Aβ_1-40 and Aβ_1-42. In recent years, it was found that a variety of truncated and modified Aβ species co-exist in AD patients’ brain. These Aβ species contributed to the progression of AD and should not be overlooked. For example, the emergence of pyroglutamated Aβ and phosphorylated Aβ is considered as symptoms of AD. And the most abundant Aβ species in AD patients’ brain should be Aβ_4-40/42, which has similar aggregation properties and toxicity with Aβ_1-40/42. Due to the elevated oxidative stress in AD patients’ brain, tyrosine nitration, dimerization and methionine oxidation were also identified in Aβ sequence, resulting in different properties. We review here the production, structure and toxicity of different Aβ species and summarize their possible roles in AD pathology.

Single atom catalysts, as catalysts with atomic scale, have a wide range of applications in the fields of hydrogen production, CO oxidation, photocatalysts, etc. Extensive efforts of experimental/theoretical studies show that the strong metal support interactions and the changes in electronic structure are the main reasons for the high selectivity and catalytic activity of the single atom catalysts. This paper mainly summarizes the recent researches on the preparation methods including coprecipitation method, successive reduction method and wet-impregnation method, catalytic performance and high catalytic selectivity of single atom catalysts. And finally, the prospects for future investigations of single atom catalysts are proposed.

Ammonia is an important chemical for producing fertilizer and also an important carbon-free energy carrier. Haber-Bosch process is the main method to synthesize ammonia. However, it suffers from some severe problems, such as the high energy consumption, the massive emission of greenhouse gas CO₂ and the poor catalytic efficiency. Recently, ammonia synthesis based on electrocatalytic nitrogen reduction reaction (NRR) by using renewable energy under mild reaction conditions has attracted wide research attention. In addition, the raw materials (N₂ + H₂O) are earth abundant. Although great advances have been achieved in electrocatalytic NRR field, some challenges including the high-cost of noble metal based electrocatalysts, the low ammonia yield and unsatisfactory Faradaic efficiency, as well as the unexplored catalytic mechanism of NRR still exist. In this review, we summarize the recent advances in electrocatalytic NRR field based on heterogeneous catalysts. Firstly, we discuss the catalytic thermodynamics and reaction mechanisms towards NRR. Secondly, a range of recently reported non-noble metal included catalysts are surveyed, including transition metal oxides/nitrides/sulfides, metal-free materials and single-metal-atom catalysts. Then, some promising strategies to enhance the catalytic activity, selectivity and efficiency are proposed, and the main methods for the determination of ammonia are also mentioned. Finally, the challenges remaining to be solved are summarized, and future perspectives are also presented.

Photocatalytic hydrogen generation, with great potential in clean energy, is an effective way to convert solar energy into hydrogen energy. The process of photocatalytic hydrogen generation mainly includes the generation and migration of electron-hole pairs as well as the REDOX reaction at the surface-active sites. In this process, due to the combination of electron-hole pairs and the limitation of surface-active sites, the electrons and holes cannot completely migrate on the catalyst surface and participate in the REDOX reaction, so hydrogen evolution efficiency is reduced. Thus for the purpose of restraining recombination of photogenerated electronic-hole and increasing surface active sites, from the two aspects of regulating the internal characteristics and external catalyst properties, the current common manipulation measures on catalyst particle size, morphology, crystal and surface active sites are analyzed, and the ways of constructing heterogeneous structure are discussed. The research results by the means of loading cocatalyst in recent years are summarized. By means of exploring how these factors influence the efficiency of catalyst activity of hydrogen evolution, ways of improving the efficiency of the hydrogen evolution method are summarized. Finally, the future research direction of photocatalytic hydrogen production is prospected, hoping to provide reference for improving the efficiency of photocatalytic hydrogen production.

Traditional polypeptides usually have the disadvantages of easy hydrolyzation, poor cell membrane permeability, and unstable conformation, which limits their application as a drug in the field of disease treatment. The conformational restriction caused by incorporation of dehydroamino acids into polypeptide can effectively improve the metabolic stability and bioavailability of peptides. In this paper, the synthesis methods and the recent applications in drug design of four kinds of dehydroamino acids including α,β-dehydro-α-amino acids, β,γ-dehydro-α-amino acids, α-dehydro-β-amino acids and α,β-dehydro-β-amino acids are reviewed, which could provide reference for the related research.

Amine compounds have been widely applied in the field of pharmaceuticals, dyes and fine chemicals due to its characteristics of chemical structure and property. Many methods for the synthesis of amine compounds are available, in which the reductive amination of nitroarenes and alcohols has attracted extensive attention because nitroarenes and alcohols with the advantages of good accessibility and stable chemical properties can directly be converted to amines by one-pot method without additional hydrogen sources. The recent progress is summarized from two aspects: catalyst and catalytic mechanism based on reaction pathways of the reductive amination of nitroarenes in this article. We introduce all kinds of catalytic systems in detail such as noble metal, photocatalyst, and so on, the catalytic performance, applicability and catalytic mechanism of which are highlighted. It needs to be pointed out that these catalytic systems show varying degrees of success as well as limitations like high cost of catalyst, narrow applicable range of substrates, excessive exogenous base, additional hydrogen source and/or toxic organic solvents. Based on the above problems, it would be desirable to develop a green, efficient, inexpensive and universal catalytic system, the catalytic mechanism of various catalysts should be systematically studied to provide guidance for the development of catalytic system on the other hand.

Functionalization of polyolefin is an efficient route to new polymer materials with high performance/price ratio. Silicon-containing functional polyolefin (SFPO) is a kind of functional polyolefin that incorporate functional silicone groups or polysiloxane segments in the structure of polyolefin. Due to special physiochemical properties of silicone groups or polysiloxane, SFPO often possesses reactivity or advanced properties and forms a new group of functional polyolefin. SFPO can function as reactive intermediates in synthesizing functional polyolefins with complex topologies (star polymer, brush polymer and graft copolymer) or preparing polyolefin covalently grafted nanomaterials. SFPO can also serve as functional additives (compatibilizer, polymer process aid and surface modifier) in developing new polyolefin materials. In recent years, researchers have obtained a series of fruitful results on the syntheses and applications of SFPO. This review aims to cover the recent progress on SFPO, which we hope may arouse the attention of related researchers and promote further achievements in related research areas.

Bottlebrush polymers are a class of comb polymers that have the unique side chain structures and properties. Functional bottlebrush polymers have found broad applications in photonic crystals, surfactants, pharmaceutical carriers, antifouling coatings and smart materials. The synthetic strategies to bottlebrush polymers by ring-opening metathesis polymerization (ROMP) exhibit various advantages, such as simple synthesis steps, high polymer graft density and uniform side chain composition. Well control of polymer composition, molecular weight and molecular weight dispersity could be achieved by ROMP. This review summarizes the synthesis of homo, block, Janus, core-shell bottlebrush copolymers via ROMP. Moreover, the advances in finely controlling the bottlebrush polymer architecture are discussed.

Organic electrode materials are expected to be the effective electrode materials for next generation of sustainable and versatile energy storage devices because of their high theoretical specific capacity, low cost, environmental friendliness and molecular designability. However, according to the principle of similar compatibility, the organic electrode materials dissolve easily in organic electrolytes, leading to rapid decay of reversible capacity, poor cycle stability and rate performance. Many researches have been devoted to restraining the dissolution of organic electrode materials by immobilization. This review focuses on the strategies of immobilization for organic electrode materials. The immobilization mechanism and the role of various strategies for different kinds of organic electrode materials are introduced, the challenges faced by organic electrode materials are then outlined, and finally the future research trend and improvement directions have been envisaged.

In recent years, the emerging organic and inorganic hybrid perovskite solar cells have made rapid progress. In just ten years, its photoelectric conversion efficiency has rapidly developed from 3.8% to the current certified efficiency of 25.2%, which is regarded as one of the most potential solar cells. Although perovskite solar cells have high photoelectric conversion efficiency comparable to polysilicon thin film cells, the long-term stability of the cells remains a major challenge hindering their commercialization. There are many defects on the surface and grain boundary of perovskite. Interface passivation is an important and effective strategy to improve the stability of perovskite solar cells. Two-dimensional perovskite materials are organic amine and inorganic layer alternate layered perovskite, with bulky organic ammonium cations. Compared with the traditional three-dimensional perovskite materials, the stability for the environment is good, with the flexible and adjustable structure. The 3D perovskite’s surface is modified by a two-dimensional perovskite to passivate defects, ensuring the stability and at the same time improving the efficiency of perovskite solar cells. In addition, suitable passivation agent molecules can also passivate defects effectively. This paper reviews the unstable factors of perovskite solar cells, summarizes the research progress in interface passivation of perovskite solar cell, points out the great potential of two-dimensional perovskite materials’ development and the principle of finding suitable passivation agent molecules, which is expected to provide useful guidance for obtaining high-performance perovskite solar cells and realizing commercialization.

Hydrocarbons play an important role in industrial productionses. The separation and purification of hydrocarbons is one of the most important industrial processes. The separation of low carbon hydrocarbon gases is extremely difficult since their physicochemical properties are similar. The minor differences are their molecular size and valence state. The traditional separation methods suffer from the high energy consumption and low efficiency. Metal-organic frameworks show superiority in separations due to their unique properties including high specific surface area, high porosity and controllable structure size. Computational simulation has been widely used in the investigations of adsorption and separation of MOFs since it can describe the adsorption and separation process at the microscopic level. This paper reviews the recent advances in computational simulations for the adsorption and separation of low-carbon hydrocarbons by metal-organic frameworks. The difficulties and future developments in the study of adsorption and separation of low carbon hydrocarbons by metal-organic frameworks have also been discussed.