Semiconductor photocatalysis, a sustainable and renewable technology, is deemed to be a new path to resolve environmental pollution and energy shortage. The development of effective photocatalysts, ...especially the metal‐free photocatalysts, is a critical determinant of this technique. The recently emerged 2D material of black phosphorus with distinctive properties of tunable direct bandgap, ultrahigh charge mobility, fortified optical absorption, large specific surface area, and anisotropic structure has captured enormous attention since the first exfoliation of bulk black phosphorus into mono‐ or few layered phosphorene in 2014. In this article, the state‐of‐the‐art preparation methods are first summarized for bulk black phosphorus, phosphorene, and black phosphorus quantum dot and then the fundamental structure and electronic and optical properties are analyzed to evaluate its feasibility as a metal‐free photocatalyst. Various modifications on black phosphorus are also summarized to enhance its photocatalytic performance. Furthermore, the multifarious applications such as solar to energy conversion, organic removal, disinfection, nitrogen fixation, and photodynamic therapy are discussed and some of the future challenges and opportunities for black phosphorus research are proposed. This review reveals that the rising star of black phosphorus will be a multifunctional material in the postgraphene era.
The recently emerged 2D material of black phosphorus has captured enormous attention owing to its distinctive intrinsic properties. Recent research on preparation methods and properties of black phosphorus is comprehensively summarized in this review. The modifications and photocatalysis applications are highlighted. Finally, the future challenges and opportunities of black phosphorus for further exploration are proposed.
Nowadays, to alleviate the growing pressure of energy shortages and environmental pollution, electrochemical energy conversion is seen as a fossil‐free, secondary pollution‐free, and highly ...efficiency pathway. Electrocatalysts, as the “heart” of the electrochemical conversion process, play a key role in accelerating reaction rates and promoting efficiency. Transition‐metal‐based layered double hydroxides (TM LDHs), one of the famous electrocatalysts, show unique 2D supermolecular‐stratified structure, excellent electronic properties, and their raw materials are easily available. In this review, electrocatalysis‐related properties of TM LDHs and the state‐of‐the‐art synthesis methods of TM LDH‐based electrocatalysts are summarized. Modifications for promoting the development of TM LDH‐based electrocatalysts are included, such as carbon materials modification, defect engineering, and noble metal loading. Then, the application of TM LDH nanosheets in the field of electrocatalysis is reviewed in detail. Finally, recent challenges, ongoing improvements, and future expectations for TM LDH nanosheets are presented.
2D transition‐metal‐based layered double hydroxides (TM LDHs), one of the most famous electrocatalysts, show excellent electronic properties and their raw materials are easily available. This review summarizes the electrocatalysis‐related properties of TM LDHs and the state‐of‐the‐art synthesis and modification methods, and then their electrocatalytic applications. Challenges, ongoing improvements, and future expectations of TM LDH nanosheets are also presented.
Diabetes is a dominating health issue with 425 million people suffering from the disease worldwide and 4 million deaths each year. To avoid further complications, the diabetic patient blood glucose ...level should be strictly monitored despite there being no cure for diabetes. Colorimetric biosensing has attracted significant attention because of its low cost, simplicity, and practicality. Recently, some nanomaterials have been found that possess unexpected peroxidase‐like activity, and great advances have been made in fabricating colorimetric glucose biosensors based on the peroxidase‐like activity of these nanomaterials using glucose oxidase. Compared with natural horseradish peroxidase, the nanomaterials exhibit flexibility in structure design and composition, and have easy separation and storage, high stability, simple preparation, and tunable catalytic activity. To highlight the significant progress in the field of nanomaterial‐based peroxidase‐like activity, this work discusses the various smart nanomaterials that mimic horseradish peroxidase and its mechanism and development history, and the applications in colorimetric glucose biosensors. Different approaches for tunable peroxidase‐like activity of nanomaterials are summarized, such as size, morphology, and shape; surface modification and coating; and metal doping and alloy. Finally, the conclusion and challenges facing peroxidase‐like activity of nanomaterials and future directions are discussed.
Recently, some nanomaterials have been found to possess unexpected peroxidase‐like activity. To highlight the significant progress in the field of nanomaterial‐based peroxidase‐like activity, this work summarizes the various smart nanomaterials that mimic horseradish peroxidase and its mechanism and development history, and their applications in colorimetric biosensing of glucose.
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•Review on metal-organic frameworks based heterogeneous Fenton-like catalysis.•Special attention has been paid to the catalytic mechanism.•The effects of pH on MOF-based Fenton-like ...catalysis are discussed.•The stability and reusability of MOF-based Fenton-like catalysts are also discussed.
The heterogeneous Fenton-like reaction is an advanced oxidation process which has gained wide spread acceptance for high removal efficiency of recalcitrant organic contaminants. Recently, the use of metal-organic frameworks (MOFs) or MOF composites as catalysts for Fenton-like catalysis has received increasing attention due to their permanent porosity and tunable open metal centers. In this article, we present an overview of the development and progress in the synthesis of different types of MOF-based catalysts and their applications for Fenton-like oxidation of organic pollutants. Special attention has been paid to the catalytic mechanism, namely the production of reactive species on the surface of the catalysts. Representative studies in this area were comprehensively reviewed. Overall, it is concluded that several classes of MOF materials with fixed metal centers are able to catalytically degrade organic pollutants over a wide pH range. Meanwhile, research in this field is still at an early stage, many improvements are required before the technology can be efficiently scaled-up and put into practice.
Graphdiyne (GDY), a rising star of 2D carbon allotropes with one‐atom‐thick planar layers, has achieved the coexistence of sp‐ and sp2‐hybridized carbon atoms in a 2D planar structure. In contrast to ...the prevailing carbon allotropes, GDY possesses Dirac cone structures, which endow it with unique chemical and physical properties, including an adjustable inherent bandgap, high‐speed charge carrier transfer efficiency, and excellent conductivity. Additionally, GDY also displays great potential in photocatalysis, rechargeable batteries, solar cells, detectors, and especially electrocatalysis. In this work, various GDY‐supported electrocatalysts are described and the reasons why GDY can act as a novel support are analyzed from the perspective of molecular structure, electronic properties, mechanical properties, and stability. The various electrochemical applications of GDY‐supported electrocatalysts in energy conversion such as hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, overall water splitting, and nitrogen reduction reaction are reviewed. The challenges facing GDY and GDY‐based materials in future research are also outlined. This review aims at providing an in‐depth understanding of GDY and promoting the development and application of this novel carbon material.
The unique properties of graphdiyne (GDY) such as adjustable inherent bandgap, ultrahigh charge carrier transfer mobility, and excellent conductivity have made it an outstanding support for various electrocatalysts. Herein, various GDY‐supported electrocatalysts are summarized, and their applications for energy conversion are reviewed. Finally, opportunities and challenges for GDY and GDY‐based materials are also proposed.
Single atom catalysts (SACs) have shown their noticeable potential and gradually become a new favorite in catalytic field due to the particular selectivity, high catalytic performance, and strong ...durability. The most important factor in the synthesis of SACs is the selection of appropriate support and formation of metal–support interaction. Among a large number of nanomaterials, MXenes can be utilized as benign supports for fixing SACs because of their expansive specific surface area, regulable bandgap, superior electronic conductivity, and strong mechanical stability. The structure and property of MXenes can be manipulated by changing transition metal elements and surface termination. Here, the uniqueness and superiority of MXenes as superexcellent supports for confining SACs are analyzed from structure and property. The synthetic strategy of MXene‐supported SACs is also summarized, especially emphasizing the immobilization of isolated atom against aggregation by utilizing the formidable metal–support covalent coordination interaction. In addition, the applications of MXene‐supported SACs in electrocatalytic field are highlighted, including hydrogen evolution reaction, oxygen evolution reaction, overall water splitting, oxygen reduction reaction, and nitrogen reduction reaction. Finally, the challenges and prospects are pointed out for the further understanding and practical application of MXene‐supported SACs in electrocatalysis.
The unique properties of MXene such as abundant surface groups and metal vacancy defects have made it a superexcellent support for single atom catalysts (SACs). Herein, the uniqueness and superiority of MXenes for confining SACs are analyzed from structure and properties. The synthetic strategies of MXene‐supported SACs and their applications in electrocatalysis are elaborated. Finally, the limitations and opportunities are also presented.
Recently, graphitic carbon nitride (g‐C3N4) has attracted increasing interest due to its visible light absorption, suitable energy band structure, and excellent stability. However, low specific ...surface area, finite visible light response range (<460 nm), and rapid photogenerated electron–hole (e−–h+) pairs recombination of the pristine g‐C3N4 limit its practical applications. The small size of quantum dots (QDs) endows the properties of abundant active sites, wide absorption spectrum, and adjustable bandgap, but inevitable aggregation. Studies have confirmed that the integration of g‐C3N4 and QDs not only overcomes these limitations of individual component, but also successfully inherits each advantage. Encouraged by these advantages, the synthetic strategies and the fundamental of QDs/g‐C3N4 composites are briefly elaborated in this review. Particularly, the synergistic effects of QDs/g‐C3N4 composites are analyzed comprehensively, including the enhancement of the photocatalytic performance and the avoidance of aggregation. Then, the photocatalytic applications of QDs/g‐C3N4 composites in the fields of environment and energy are described and further combined with DFT calculation to further reveal the reaction mechanisms. Moreover, the stability and reusability of QDs/g‐C3N4 composites are analyzed. Finally, the future development of these composites and the solution of existing problems are prospected.
This review summarizes the mainly synthetic strategies, the fundamentals, stability and reusability of quantum dots (QDs)/graphitic carbon nitride (g‐C3N4) composites, as well as their applications in the fields of energy and environment. Particularly, the synergistic effects of QDs/g‐C3N4 are highlighted and analyzed comprehensively. Finally, the future development of these new materials and existing problems to be solved are prospected.
This paper investigated the key factors and mechanisms of sulfamethazine (SMT) sorption on a novel carbonaceous nanocomposite, and the effects of harsh aging on SMT sorption in the presence and ...absence of soil and before as well as after aging. The carbonaceous nanocomposites were synthesized by dip-coating straw biomass in carboxyl functionalized multi-walled carbon nanotubes solution and then pyrolyzed at 300 °C and 600 °C in the absence of air. The sorption performance of high temperature carbonaceous nanocomposite on SMT was excellent, as measured sorption distribution coefficient in the order of 103–105.5 L kg−1. Carbonaceous nanocomposites were aged either alone or mixed with soil via exposure to nutrients and soil extract (biological aging) or 80 °C for 100 d (chemical aging). No obvious effects of harsh aging on SMT sorption were observed in the presence of soil and/or biological and chemical aging. The primary mechanisms for SMT sorption included partition caused by Van der Waals forces and adsorption caused by hydrogen bonding and π-π electron-donor-acceptor interaction. Comprehensively considering the cost, renewability, and the application to real water samples, the carbonaceous nanocomposites have potential in removal of SMT and possibly other persistent organic pollutants from wastewater.
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•Carbonaceous nanocomposites were synthesized by dip-coating and slow pyrolysis.•Sorption distribution coefficient of sulfamethazine was 103–105.5 L kg−1.•No obvious effects of harsh aging on sulfamethazine sorption were observed.•The application to real sulfamethazine wastewater is highly feasible.
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•Review on M/MC nanoparticle@MOF based heterogeneous photocatalysis.•Special attention has been paid to the catalytic mechanism.•The synergistic effects between M/MC NP cores and MOF ...shells are discussed.•The future development prospects of this technology are proposed.
Photocatalysis is a promising technology that can convert solar energy into chemical energy. However, developing photocatalyst that could be put into the practical application remains a big challenge worldwide. In the recent years, an emerging type of core–shell/core–shell like composites, in which the metal or metal-containing nanoparticles (M/MC NPs) cores are encapsulated by the metal–organic frameworks (MOFs) shells, have attracted increasing attention in photocatalysis. These M/MC NP@MOF nanocomposites are believed to be one of the most effective and convenient ways to achieve property synergies of MOFs and M/MC NPs. Even though this field is currently in its infancy, the promising results obtained have validated the potential use of M/MC NP@MOF nanocomposites in practical applications. In this review, the fundamental mechanisms of photocatalysis were briefly introduced. The synthesis of M/MC NP@MOF nanocomposites and related photocatalytic applications (such as photocatalytic hydrogen generation and Cr(VI) reduction) are summarized and exemplified. Special emphasis is given to the synergistic effects between the MOFs shell and NPs core that result in an enhanced performance in heterogeneous photocatalysis. Finally, the unsolved problems of M/MC NP@MOF nanocatalysts are discussed and the future development prospects are proposed.
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•Metal sulfide/MOF-based visible-light-driven hydrogen evolution was reviewed.•Special attention has been paid to the catalytic mechanism.•The synergistic effects between metal ...sulfide and MOF shells are discussed.•The future development prospects of this technology are proposed.
Solar energy driven photocatalytic hydrogen (H2) production from photocatalytic water splitting is considered as one of the most promising technologies to solve the energy and environmental crises. In the recent years, metal sulfide/MOF-based composites have attracted increasing attention in visible-light-driven photocatalytic H2 production owing to their multiple advantages, such as high photochemical stability, broad light absorption and effective charge separation efficiency. Even though this field is currently in its infancy, the promising results obtained suggest that these composite photocatalysts have high potential for practical applications. In this review, we provide an overview of the progress in the design and synthesis of various metal sulfide/MOF-based nanocomposites for applications in photocatalytic H2 production. Special consideration has been given to the synergistic effects between metal sulfide and MOF (or MOF derivative) that result in an enhanced photocatalysis. We also present some important examples showing that non-noble metal cocatalysts could serve as efficient cocatalysts for promoting photocatalytic H2 production. Finally, the remaining issues in this field are discussed and future directions and challenges are outlined.
