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Core–shell structures, where the "guest" material is encapsulated within a protective shell, integrate the advantages of different materials to enhance the overall properties of the composite. Covalent–organic frameworks (COFs) are favorable candidates for composing core–shell structures due to their inherent porosity, good activity, excellent stability, and other advantages. In particular, COFs as shells to encapsulate other functional materials are becoming increasingly popular in the fields of environmental remediation and energy conversion. However, there is a lack of reviews on COF‐based core–shell materials. In this context, this review provides a systematic summary of the current research on COF‐based core–shell composites. First, a simple classification is made for COF‐based core–shell composites. The second part of the review describes the main synthesis methods. The changes brought about by the COF shell and core–shell structures on the properties of the composites and their applications in photocatalysis, electrocatalysis, adsorption, sensing, and supercapacitors are then emphasized. Finally, new perspectives on the future development and challenges of composites are presented. The purpose of this study is to provide future insights into the design and application of COF‐based core–shell composites. [ABSTRACT FROM AUTHOR]

The photo-Fenton-like catalytic process has shown great application potential in environmental remediation. Herein, a novel photo-Fenton-like catalyst of Bi 2 WO 6 nanosheets decorated hortensia-like CoAl-layered double hydroxides (Bi 2 WO 6 /CoAl-LDHs) was synthesized via hydrothermal process. The optimized Bi 2 WO 6 /CoAl-LDHs composite performed the high-efficiency photo-Fenton-like catalytic performance for oxytetracycline (OTC) removal (98.47%) in the mediation of visible-light and H 2 O 2. The comparative experiment, technical characterization and density functional theory calculation results indicated that the efficient photo-Fenton-like catalytic performance of Bi 2 WO 6 /CoAl-LDHs was attributed to the synergistic action of the Fenton-like process of cobalt ions in CoAl-LDHs, an internal electric field and the S-scheme heterojunction form between Bi 2 WO 6 and CoAl-LDHs, which could significantly promote the active substance formation and the photocatalytic process in the catalytic system. This study will stimulate the new inspiration of designing the efficient catalytic system for environmental remediation and other fields. [Display omitted] • Hortensia-like Bi 2 WO 6 /CoAl-LDHs composite was synthesized via hydrothermal process. • Optical-electrical properties and H 2 O 2 adsorption behavior of samples were calculated by DFT. • Bi 2 WO 6 /CoAl-LDHs composite exhibited high photo-Fenton-like catalytic activity of antibiotic. • An internal electric field and S-scheme heterojunction form between Bi 2 WO 6 and CoAl-LDHs. [ABSTRACT FROM AUTHOR]

Recently, persulfate-based advanced oxidation processes (persulfate-AOPs) are booming rapidly due to their promising potential in treating refractory contaminants. As a type of popular two-dimensional material, layered double hydroxides (LDHs) are widely used in energy conversion, medicine, environment remediation and other fields for the advantages of high specific surface area (SSA), good tunability, biocompatibility and facile fabrication. These excellent physicochemical characteristics may enable LDH-based materials to be promising catalysts in persulfate-AOPs. In this work, we make a summary of LDHs and their composites in persulfate-AOPs from different aspects. Firstly, we introduce different structure and important properties of LDH-based materials briefly. Secondly, various LDH-based materials are classified according to the type of foreign materials (metal or carbonaceous materials, mainly). Latterly, we discuss the mechanisms of persulfate activation (including radical pathway and nonradical pathway) by these catalysts in detail, which involve (i) bimetallic synergism for radical generation, (ii) the role of carbonaceous materials in radical generation, (iii) singlet oxygen (1O 2) production and several special nonradical mechanisms. In addition, the catalytic performance of LDH-based catalysts for contaminants are also summarized. Finally, challenges and future prospects of LDH-based composites in environmental remediation are proposed. We expect this review could bring new insights for the development of LDH-based catalyst and exploration of reaction mechanism. [Display omitted] • Systematic introduction of different persulfate activation mechanisms by LDH-based catalysts. • Unique "intercalation effect" of LDH-based catalysts have been discussed. • Discussion on the effect of tailoring the morphology of LDHs for improving catalytic performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • The magnetic covalent organic frameworks (MCOFs) are divided into three categories. • The main characteristics of MCOFs and different synthesis methods are introduced. • The application scope of MCOFs is comprehensively investigated. • The application mechanism of MCOFs in various aspects is explained reasonably. • The future development and challenges of MCOFs have been prospected. Magnetic nanoparticles (MNPs) possess outstanding rapid magnetic separation ability due to their excellent superparamagnetism and stability. Covalent organic frameworks (COFs) have the advantages of porous structure, large specific surface area, remarkable acid–base and thermal stability that can form novel magnetic nanocomposites with MNPs. The formed magnetic covalent organic frameworks (MCOFs) composite material owns high saturation magnetization and prominent chemical stability, which is the great potential material in the fields of environmental remediation and biological applications. Based on the current research results, firstly, this review further simplifies the classification according to the composition and functionalization of the composite: primitive MCOFs, functionalized MCOFs, composite of Fe/Co/Ni and its alloys with COFs. Secondly, several major characteristics and diverse synthesis methods of MCOFs composites are described. Thirdly, the applications of MCOFs in adsorption and enrichment detection, catalysis, sensing and biomedical aspect are reviewed in detail, and the mechanisms of these processes have been fully and reasonably explained. Finally, the future development and challenges of MCOFs composite materials have been prospected. This work aims to provide a theoretical basis for the synthesis and design of MCOFs composite materials in the future. [ABSTRACT FROM AUTHOR]

• Recent advances in photocatalysts modified with fullerene and its derivatives are overviewed. • Exclusive properties and photocatalytic mechanisms of fullerene and its derivatives. • Main synthesis strategies and affecting factors are discussed. • Excellent photocatalytic applications of photocatalysts modified with fullerene and its derivatives. • Challenges and directions on future design, synthesis and applications. Fullerenes possess high chemical stability, large specific surface area, good electrical conductivity and unique three-dimensional structure. In this paper, we provide a general overview of the latest research results of fullerene-based photocatalysts. Firstly, the current status of semiconductor materials and fullerenes in photocatalytic applications are briefly introduced. Secondly, introduced action mechanisms of photocatalysts modified by fullerene C 60 and its derivatives, including basic structure, exclusive properties and its effect in photocatalysis and material preparation process. Thirdly, factors affecting material effectiveness and the synthesis strategy of composite photocatalyst modified by fullerene are introduced. Meanwhile, the application advances of the photocatalysts are introduced, including in the degradation of pollutants, organic synthesis, hydrogen production, antibacterial and disinfection in water. Finally, the development trends of fullerenes and their derivatives in photocatalysis are also summarized, including theoretical calculations, the morphological structure control, stable derivatives and increase the selectivity, and new other types of fullerene materials. [ABSTRACT FROM AUTHOR]

• Synthesis methods, structures and properties of QD-MOF composites. • Progress of QD-MOF composites in environmental remediation and energy production. • Detailed photocatalytic mechanism of QD-MOF composites. • The presents challenges of QD-MOF composites and the prospects for their future development. Photocatalysis is an efficient technology for energy production and environmental remediation. The composites of metal organic frameworks (MOFs) combined with quantum dots (QDs) allow high photocatalytic ability. Recently, these composites have been applied increasingly in the fields of energy production and environmental remediation. Even so, QD-MOF composites still have some shortcomings in the field of photocatalysis. In this review, the synthesis methods and structures as well as the applications of QD-MOF composites in water splitting for hydrogen production, carbon dioxide (CO 2) reduction to produce methane (CH 4), organic dye degradation, Cr(VI) reduction, and nitric oxide (NO) oxidation are discussed. The mechanisms of these processes are also described in detail. Finally, new insights into the future development and challenges of the composite are proposed to advance further development of the research area. [ABSTRACT FROM AUTHOR]