Electrochemical impedance spectroscopy (EIS) is one of the most powerful experimental methods to study electrochemical systems, and has been extensively used in the analysis of lithium battery systems, especially to determine kinetic and transport parameters, understand reaction mechanisms, and to study degradation effects in past two decades. In this paper, the electrode polarization process in lithium ion batteries which includes three basic physical and chemical processes, namely, electronic transport process, ionic transport process and electrochemical reaction process, is briefly described, and the EIS characteristics of each transport and reaction stage of the three basic physical and chemical processes are discussed, especially the mechanism of inductance formation and contact impedance is expounded in detail. Moreover, porous electrode theory and its application in lithium ion batteries are reviewed, and emphasis is put upon the principle and method of numerical simulation of impedance with physics-based lithium-ion batteries models. Furthermore, the typical EIS characteristics and the attribution of each time constant of the electrode materials for lithium ion batteries such as graphite, silicon, simple binary transition metal oxides, LiCoO₂, spinel LiMn₂O₄, LiFePO₄, spinel Li₄Ti₅O₁₂ and transition metal oxides are also discussed. Finally, the challenges currently faced by EIS are identified and possible directions and approaches in addressing these challenges are suggested.

Contents

Single-atom catalyst has the advantages of low coordination number, special coordination environment, high atomic utilization, and high uniformity of catalytic sites. It is the bridge between homogeneous and heterogeneous catalysts, which helps to better understand the nature of catalytic reaction. In this paper, the synthetic methods of graphene-based single-atom catalysts in recent years are reviewed, including atomic layer deposition, impregnation-calcination, defect trapping, coordination anchoring and some other novel methods, with a focus on the preparation process, principle and characterization results of these methods. Based on this, the performance of graphene-based metal single-atom catalysts in catalysis is illustrated and analyzed, and the purpose is to provide guidance and reference for the preparation of single-atom catalysts.

Microporous organic polymers(MOPs) is one of the most promising new materials for many applications, such as gas capture and storage, gas separation, organic vapor adsorption, heterogeneous catalyst carrier, water treatment, functional materials and so on, making them to be a research hotspot. This is due to the fact that MOPs have shown many advantages in, for example, excellent thermal stability, chemical stability, low density, high specific surface area, and molecular pore size architecture. Generally, molecular building blocks, particularly being symmetrical in plane or space, are the core architecture in the synthesis of MOPs. Among various building molecules, multi-substituted adamantane, has been reported as a new molecular "knot" candidate for the creation of MOPs, by connecting with a "linkage" molecule, thanks to its highly stereoscopic symmetrical structure and structural rigidity. In addition, the adamantane-based MOPs have shown many advantageous and interesting properties in terms of synthetic yield, structural stability, pore size distribution, gas/vapor adsorption and separation. This mini review focuses on recent progress in the synthesis and interesting properties of the MOPs with adamantane incorporated(MOP-Ad). The MOP-Ad polymers are classified into phenyl-linkage, Schiff base linkage, imide linkage, and nitrogen-rich(benzimidazole and triazine) categories. Special attention is paid to the similarities and differences with comparison in the synthetic route, structural characteristics, stability and adsorption properties. Besides, some emerging new types of Ad-polymers are briefly introduced and an outlook is also proposed for the MOP-Ad.

N-alkyl amines are an important class of molecules in the chemical industry and are extensively applied in the syntheses of dyes, pharmaceuticals, agrochemicals, surfactants, rubber ingredients, and functional materials. Given the importance of N-alkyl amines, the development of efficient synthetic methodologies to synthesize these amines is of broad interest. Among various methods, the catalytic alcohol amination has been viewed as effective and green method for synthesis of N-alkyl amines because alcohol is readily available, and water is generated as the sole by-product. This review describes developments and recent advances in the alcohol amination with different heterogeneous catalyst systems, including nickel, copper, palladium, platinum, cobalt, manganese, iron, gold, ruthenium, silver, and other catalyst systems. The frontiers and future of the topic are also given.

The sillenite-based photocatalytic materials have attracted the researchers’ interests because of their unique crystal and electronic structures, as well as remarkable visible light absorption abilities. However, they usually have poor photocatalytic activities and stabilities owing to their structural and functional defects, such as high recombination efficiencies of photo-generated charges, low quantum yields, limited active sites, and insufficient exposure of active crystal planes. Therefore, how to achieve optimal modulation of photocatalytic activity and stability based on the structural design and functional integration of sillenite-based photocatalysts on the micro-nano scale is still a key scientific problem. This paper mainly reviews the synthesis strategies of sillenite-based micro/nanomaterials and their latest research progress in the field of photocatalysis, especially focusing on the morphology control, noble metal loading, semiconductor/graphene coupling, ion doping and the development of new sillenite-based photocatalytic systems. Moreover, the photocatalytic applications of sillenite materials are discussed. Finally, the future research prospects of such photocatalytic materials are also pointed out.

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.

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.

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.

Hematological malignancies(HM) is a kind of malignant disease of hematology system which seriously threatens human health, mainly involving bone marrow, blood and lymphatic tissue. The quantification of biomarkers in hematological malignancies is the key for fine stratification analysis, personalized targeted therapy and prognostic improvement. In this paper, the specific types and the commonly used detection methods at home and abroad of the hematological malignancies related biomarkers are summarized and compared. Specifically, the latest application of new electrochemical biosensor for the hematological malignancies related biomarkers is mainly described. Furthermore, the summary of its future directions and the potential applications is given, which provides reference for the further research and application of the biomarkers in hematological malignancies.

Contents
1 Introduction
2 Biosensor technology
3 Application of electrochemical biosensor technology
3.1 Electrochemical DNA biosensor
3.2 Electrochemical immunosensor
3.3 Circulating tumor cells (CTCs) electrochemical biosensor
3.4 Glucose electrochemical biosensor
3.5 Hydrogen peroxide electrochemical biosensor
3.6 Electrochemical biosensor for small molecules of metabolite detection
4 Conclusion

Contents
1 Introduction
2 Common ECL system and ECL mechanism
2.1 Annihilation type ECL mechanism
2.2 Co-reactant type ECL mechanism
3 Research advances of MIPs-based ECL analysis
3.1 MIPs-ECL sensor based on solid-state light-emitting electrode
3.2 MIPs-ECL sensor based on non-solid-state Light-emitting electrode
3.3 MIPs based-solid phase extraction coupled with ECL
4 Conclusion

Contents
1 Introduction
2 SECM operation modes
2.1 Feedback mode
2.2 Generation-collection mode
3 SECM used as tool for photoelectrochemical energy research
4 SECM used as screening technique for developing metal ion doped WO₃ photocatalysts
5 Conclusion and outlook

Contents
1 Introduction
2 Preparation of ERGO modified electrodes
2.1 Indirect electrochemically reduced method
2.2 Direct electrochemically reduced method
3 Classification of ERGO modified electrodes
3.1 Intrinsical ERGO modified electrodes
3.2 The composite modified electrodes based on inorganic nanoparticles and ERGO
3.3 The composite modified electrodes based on organic compounds and ERGO
3.4 The composite modified electrodes based on inorganic-organic and ERGO
4 Electrocatalytic and electrochemical applications of ERGO modified electrodes
4.1 Electrochemical analysis of small molecules
4.2 Electrochemical analysis of molecules containing aromatic structure
4.3 Electrochemical analysis of biological molecules (protein and DNA)
5 Conclusion and outlook

Contents
1 Introduction
2 Mechanism of electrochemical analyses of anion recognition
3 Anion receptors with redox unit
3.1 Anion receptors based on ferrocene
3.2 Others
4 Prospects

DNA methylation, which refers to methyltransferases (MTases)-catalyzed covalent addition of a methyl group to adenine or cytosine residues in the specific DNA sequence, is one of the hottest research areas on epigenetic modification of genomic DNA. According to numerous studies, DNA methylation may cause the change of DNA structure, stability and interaction mode between DNA and protein, thus affecting gene expression, which may lead to many neurodegenerative diseases, immune system diseases and even cancer. Therefore, development of sensitive, selective, simple, and economical methods for DNA methylation determination is highly required. With increasing progress in the methylation studies, a series of detecting techniques has been developed to match various requirements of methylation studies. All of these study methods can be divided into four groups: genome-wide methylation extent analysis, gene-specific methylation analysis, methylation transferase activity analysis and new methylated sites screening. Among these methods, electrochemical techniques have been widely used for DNA methylation determination and MTases activity. Here we briefly review the detection of DNA methylation. Then more detail in the work on the electrochemical method are described, including direct electrochemical analysis methods, indirect electrochemical analysis methods, electrogenerated chemiluminescence methods and photoelectrochemical methods. In the end, the prospects of DNA methylation analysis are introduced.

Contents
1 Introduction
2 Analysis methods for DNA methylation
3 Electrochemical analysis methods for DNA methylation
3.1 Direct electrochemical analysis methods for DNA methylation
3.2 Indirect electrochemical analysis methods for DNA methylation
3.3 Electrogenerated chemiluminescence methods for analysis of DNA methylation
3.4 Photoelectrochemical methods for analysis of DNA methylation
4 Conclusion

With the development of monoclonal antibody and immunological detection technology, the detection of tumor marker proteins becomes the most important method for early screening and diagnosis of cancer. On the other hand, with the development of molecular recognition and surface assembly techniques, electrochemical analysis displays some unique advantages in biological analysis, such as simple operation, easy-to-miniaturize nature, low cost, sensitivity, and so on. Especially in recent years, various antibodies, aptamers and peptides that can specifically bind with tumor marker proteins have been screened out. Various nanomaterials and nanotechnologies have been explored in the application to electrochemical analysis. Many novel techniques for molecule labeling, surface self-assembly, and signal amplification have been proposed. So, electrochemical analysis obtains unprecedented opportunities in the quantitative detection of tumor marker proteins, and more and more achievements are reported. In this review, by commenting on some typical work conducted in the lab of the authors, we summarize the recent research progress on the electrochemical analysis of tumor marker proteins and make an outlook on the trends of the related research fields in the future.

Contents
1 Introduction
2 Electrochemical immunoassay based on antibody
3 Electrochemical analysis based on aptamer
4 Electrochemical analysis based on polypeptide
5 Electrochemical analysis based on other recognition elements
6 Conclusion and outlook

Extracellular electron transfer (EET) between electrochemically active microorganisms and electrodes plays a key role in microbial electrochemical systems (MESs) functioning of energy generation, bioremediation, etc. At present, researchers have a very limited understanding of the mechanism of EET, which is one of the major bottlenecks in application of MESs. Compared with direct electron transfer which requires a direct contact between microbial functional proteins and electrode, mediated electron transfer use electron transfer mediators (ETMs) which have reversible redox activities accompanies by high-efficiency EET for transporting electrons. ETMs serve as the middle electron acceptor, once reduced, can transfer electrons to terminal electron acceptor where upon it becomes re-oxidized. In principle, ETMs molecules could cycle thousands of times,thus, have a significant effect on the turnover of the terminal oxidant (e.g.iron) in certain circumstances.This review summarizes the recent advances of EET mechanisms with focus on mediated EET in MESs. Furthermore, we have highlighted the research trends of ETMs in MES,which will promote the practical applications of MESs in bioremediation, energy generation and so on.

Contents
1 Introduction
2 Roles of electron transfer mediators in extracellular electron transfer
3 Properties of electron transfer mediators
4 Classification of electron transfer mediators
5 Electron transfer mediators and their electron transfer mechanism
5.1 Exogenous electron transfer mediators
5.2 Endogenous electron transfer mediators
6 Outlook

In this paper, we review the preparation methods of carbon nanotube (CNT)/graphene composite materials for the electrode of supercapacitors, and introduce the developments of CNT/graphene/pseudo-capacitive material ternary composite materials with highly electrochemical performance. The rational designed CNT/graphene composite nanostructures could largely utilize the characteristics of carbon nanomaterials for electrochemical double-large supercapacitors, such as large specific area, high conductivity and befitting porous structure, and also achieve large mass loading of pseudo-capacitive materials with high dispersion for pseudo-capacitors. As a result, these composite materials are promising candidates for the electrode materials of high-performance supercapacitors with high capacitance, excellent rate performance and long lifetime.

Contents
1 Introduction
2 The preparation strategies of carbon nanotube/graphene composites
2.1 The assembling based on π-π interaction
2.2 The assembling based on electrostatic attraction
2.3 In-situ growth
2.4 Other methods
3 Ternary composite electrodes based on graphene, carbon nanotube and pseudo-capacitive materials
3.1 Carbon nanotube/graphene/conductive polymer
3.2 Carbon nanotube/graphene/metallic oxides (hydroxides)
4 Conclusion

Photoelectrochemical sensor is a dynamically developed and promising analytical method, based on the photoelectrochemical process and chemical or biological probing recognition. Benefitting from the separation of the excitation source (light) and electrochemical detection signal (photocurrent), the photoelectrochemical sensor possesses many intrinsic advantages, such as higher sensitivity with low background signals, simpler and low-cost instruments, and inherent miniaturization. It has received an increasing attention and shows an extensive application potential in rapid and high-throughput biological and chemical assays. Under light irradiation, the photocurrent is recorded on the basis of the electron transfer among the photoelectrochemical materials in excited state, electrode surface, and electrolyte. Depending on the photocurrent change resulting from the interactions between various sensing elements and their target analytes, the quantitative photocurrent-analyte relationship is obtained. There are two key portions in the development of photoelectrochemical sensor: the fabrication of the photosensitive layer and the assembly of the molecular recognition layer at the transducer surface. The design and fabrication of photosensitizer, deriving from photoelectrochemically active species and the exploitation of exquisite sensing mechanisms are of extreme importance in the achievements of acceptable sensitivity. In this paper, the sensing principle of photoelectrochemical sensor, lasted applications, design and fabrication of photosensitizer and developments of sensing strategies are reviewed.

Contents
1 Photoelectrochemistry and photoelectrochemical process
2 Introduction to photoelectrochemical sensor
3 Photoelectrochemically active species for the design and fabrication of photoelectrochemical sensor
3.1 Organic photovoltaic molecule
3.2 Conducting polymer
3.3 Inorganic semiconductor and its composites
3.4 Other photovoltaic materials
4 Signal generating mechanism and sensing strategies
4.1 Direct charge transmission and redox reaction
4.2 Signal-off strategy derived from steric hindrance based on molecular recognition
4.3 Enzymatic inhibition and enzymatic catalysis
4.4 Local surface plasma resonance (LSPR) of noble metal nanoparticles and energy transfer in exciton-plasmon interaction (EPI)
4.5 Other probing strategies
5 Prospective of photoelectrochemical sensor