Cyclodextrin-based supramolecular assemblies: a versatile toolbox for the preparation of functional porous materials

The discovery of ordered mesoporous materials in 1992 by Mobil Oil Corporation scientists has opened great opportunities for new applications in many emerging fields such as heterogeneous catalysis, biocatalysis, energy conversion, biosensors, photocatalytic devices and environmental technologies. Porous materials are grouped by the International Union of Pure and Applied Chemistry (IUPAC) into three classes according to their pore diameter: microporous (<?2 nm), mesoporous (2–50 nm) and macroporous (>?50 nm). One of the most versatile methods for the preparation of those materials is the soft template approach which combines the sol–gel process with molecular self-assembly. While the micelles formed by ionic or nonionic surfactants, as well as amphiphilic polymers, have been extensively used as templates, the supramolecular assemblies formed between cyclodextrins and block copolymers have been less investigated, despite their large chemical and structural diversity. This review article focuses mainly on nanostructured porous inorganic materials derived from cyclodextrins or cyclodextrin-based assemblies. More than 100 references are described and discussed, in which we look both at their synthesis and characterization, as well as their applications in the emerging fields of heterogeneous catalysis and photocatalysis. A special attention is paid to the evaluation of the critical parameters that need to be controlled for improving their (photo) catalytic performances.     

固-液异相催化剂在环境科学领域中的应用

异相催化是催化反应的重要组成部分，其应用十分广泛。固一液异相催化作为环境科学领域中的一项比较新颖的技术，在研究污染物在多介质环境中的迁移转化行为、开发受污染环境修复及污废水处理新技术等诸多方面都具有很大的发展潜力。因此，对不同类型固一液异相催化剂在环境科学领域的应用研究逐渐成为国内外环境科学领域的研究热点之一。其中，金属和金属氧化物因对某些氧化一还原反应具有较好的催化作用，在饮用水脱氮、污废水脱卤及深度氧化处理等水处理领域的应用较为广泛；固态酸催化剂能催化聚合、裂化、水解反应，因此与某些有机污染物的降解密切相关；将同相催化剂固定化为异相催化剂，同样成为新技术开发的方向之一；天然催化剂对污染物在多介质环境中行为影响的研究近年来也屡有发表。此外，载体因对催化剂的活性及应用具有重要影响，也日益受到关注。文章对环境科学领域中固一液异相催化剂的应用研究进行了综述。     

Crystalline mesoporous transition metal oxides: hard-templating synthesis and application in environmental catalysis

Mesoporous silicas such as MCM-41 and SBA-15 possess high surface areas, ordered nanopores, and excellent thermal stability, and have been often used as catalyst supports. Although mesoporous metal oxides have lower surface areas compared to mesoporous silicas, they generally have more diversified functionalities. Mesoporous metal oxides can be synthesized via a soft-templating or hard-templating approach, and these materials have recently found some applications in environmental catalysis, such as CO oxidation, N₂O decomposition, and elimination of organic pollutants. In this review, we summarize the synthesis of mesoporous transition metal oxides using mesoporous silicas as hard templates, highlight the application of these materials in environmental catalysis, and furnish some prospects for future development.     

Supported single-atom catalysts: synthesis,characterization, properties,and applications

In recent years, there has been a wide research in supported single-atom catalysts (SACs), which contain only isolated individual metal atoms dispersed on an appropriate support or coordinated with the surface atoms of the support. The SACs exhibit many fascinating characteristics including high activity, selectivity, and maximum atomic utilization. These characteristics arise from the low coordination status, quantum size effect, and the strong metal–support interaction, which have proved to be very powerful in many typical heterogeneous catalysis field including oxidation, hydrogenation, the water–gas shift reaction, methanol steam reforming, electrocatalysis, and photocatalysis. In this review, we summarized the recent progress in synthesis, characterizations, properties, and applications of SACs.     

Cyclodextrins,from molecules to applications

Cyclodextrins are among the most remarkable macrocyclic molecules with significant theoretical and practical impacts in chemistry and biology. Cyclodextrins belong to the family of cage molecules due to their structure, which is composed of a hydrophobic cavity that can encapsulate other molecules. Indeed, the most characteristic feature of these compounds is their ability to form inclusion complexes with various molecules through host–guest interactions. This is at the origin of many applications. It is well known and widely reported in the literature that cyclodextrins and their derivatives have a wide variety of practical applications including pharmacy, medicine, foods, cosmetics, toiletries, catalysis, chromatography, biotechnology, nanotechnology, and textile industry. Cyclodextrins are also the object of numerous fundamental studies. In this review, we chose to highlight selected works on cyclodextrins published over the last 5 years by different research groups. The main objective is to summarize some of the recent developments related to the applications of cyclodextrins.     

Biofuel production,hydrogen production and water remediation by photocatalysis,biocatalysis and electrocatalysis

The energy crisis and environmental pollution have recently fostered research on efficient methods such as environmental catalysis to produce biofuel and to clean water. Environmental catalysis refers to green catalysts used to breakdown pollutants or produce chemicals without generating undesirable by-products. For example, catalysts derived from waste or inexpensive materials are promising for the circular economy. Here we review environmental photocatalysis, biocatalysis, and electrocatalysis, with focus on catalyst synthesis, structure, and applications. Common catalysts include biomass-derived materials, metal–organic frameworks, non-noble metals nanoparticles, nanocomposites and enzymes. Structure characterization is done by Brunauer–Emmett–Teller isotherm, thermogravimetry, X-ray diffraction and photoelectron spectroscopy. We found that water pollutants can be degraded with an efficiency ranging from 71.7 to 100%, notably by heterogeneous Fenton catalysis. Photocatalysis produced dihydrogen (H₂) with generation rate higher than 100 μmol h⁻¹. Dihydrogen yields ranged from 27 to 88% by methane cracking. Biodiesel production reached 48.6 to 99%.

     

Bio-based materials for high-end electronics applications

During the past decade, a shift of focus onto greener alternatives to petroleum-based plastics has spurred the development of bio-based resins for plastic development. This has led to a positive marketing image for companies making the switch to resins from renewable resources. This shift of focus is further reinforced by corporations, which are committed to a reduction in their greenhouse gas emissions and product environmental footprints. Here, we present a perspective on the use of renewable materials in durable goods applications and the challenges and advantages associated with the use of renewable materials. Replacement of petroleum-based acoustic foam with that derived from sustainable resources and qualification of thermoplastic polylactic acid blends for enclosure covers has been demonstrated. The technical details of the materials development required for use in durable goods, and their characterization is also discussed.     

Green synthesis of metal nanoparticles using Garcinia extracts: a review

Environmental Chemistry Letters - The demand for nanoparticles has been increasing rapidly in recent years due to their unique properties of interest for a wide range of applications. Several...     

以工业级TiO2为载体负载不同助催化剂V2O5基脱氮催化剂的性能

在工业级TiO2载体上,通过浸渍法负载V2O5,WO3和MoO3等活性物质,制备不同V2O5基的烟气脱氮催化剂．在固定床反应器中测试DeNOx活性,研究不同的助催化剂(WO3和MoO3)对该类型催化剂DeNOx活性的影响,结果表明,在三元催化剂中,V2O5是主活性物质,MoO3和WO3是助催化剂,此外,V2O5-MoO3／TiO2的脱氮效率高于V2O5-WO3／TiO2,但N2O的生成量较大。     

Inductively coupled plasma‐atomic emission spectroscopy in air and water pollution analysis†

The inductively coupled plasma (ICP), when employed as an excitation source in optical atomic emission spec.troscopy (AES), is finding widespread utilization for single and multielement inorganic trace analysis of pollutants. The recent availability of commercial ICP‐AES instrument systems has stimulated applications for the determination of metals and metalloids in diverse materials ranging from air particulates and fly ash to industrial effluents, sewage, and hard, soft, and saline waters.

The capabilities and limitations of ICP‐AES for applications in air and water pollution analysis are reviewed, and a number of recent examples presented.     

Cerium dioxide and composites for the removal of toxic metal ions

The presence of contaminants in potable water is a cause of worldwide concern. In particular, the presence of metals such as arsenic, lead, cadmium, mercury, chromium can affect human health. There is thus a need for advanced techniques of water decontamination. Adsorbents based on cerium dioxide (CeO₂), also named ‘ceria,’ have been used to remove contaminants such as arsenic, fluoride, lead and cadmium. Ceria and composites display high surface area, controlled porosity and morphology, and abundance of functional groups. They have already found usage in many applications including optical, semiconductor and catalysis. Exploiting their attractive features for water treatment would unravel their potential. We review the potential of ceria and its composites for the removal of toxic metal ions from aqueous medium. The article discusses toxic contaminants in water and their impact on human health; the synthesis and adsorptive behavior of ceria-based materials including the role of morphology and surface area on the adsorption capacity, best fit adsorption isotherms, kinetic models, possible mechanisms, regeneration of adsorbents; and future perspectives of using metal oxides such as ceria. The focus of the report is the generation of cost-effective oxides of rare-earth metal, cerium, in their standalone and composite forms for contaminant removal.     

Activated carbons and amine-modified materials for carbon dioxide capture — a review

Rapidly increasing concentration of CO₂ in the atmosphere has drawn more and more attention in recent years, and adsorption has been considered as an effective technology for CO₂ capture from the anthropogenic sources. In this paper, the attractive adsorbents including activated carbons and amine-modified materials were mainly reviewed and discussed with particular attention on progress in the adsorbent preparation and CO₂ adsorption capacity. Carbon materials can be prepared from different precursors including fossil fuels, biomass and resins using the carbonization-activation or only activation process, and activated carbons prepared by KOH activation with high CO₂ adsorbed amount were reviewed in the preparation, adsorption capacity as well as the relationship between the pore characteristics and CO₂ adsorption. For the amine-modified materials, the physical impregnation and chemical graft of polyethylenimine (PEI) on the different porous materials were introduced in terms of preparation method and adsorption performance as well as their advantages and disadvantages for CO₂ adsorption. In the last section, the issues and prospect of solid adsorbents for CO₂ adsorption were summarized, and it is expected that this review will be helpful for the fundamental studies and industrial applications of activated carbons and amine-modified adsorbents for CO₂ capture.     

绿色化学研究与生态环境保护

绿色化学是指利用一系列原理来降低或消除在化工产品的设计、生产及应用中有害物质的使用和产生的科学。它致力于从源头上制止污染物的生成。文章从非传统的绿色原材料、溶剂、试剂、催化剂、安全化学品及合成方法方面综述了绿色化学的研究进展。绿色化学从材料和能源的内在性质上面对生态环境问题的挑战，在分子水平上设计结构及其相关的性质，通过减少内在的危害而使生态系统的发展具有可持续性。发展绿色化学是实现生态环境保护的途径。     

Nanoconfinement engineering for enchanced adsorption of carbon materials,metal–organic frameworks,mesoporous silica,MXenes and porous organic polymers: a review

In material synthesis, nanoconfinement acts both as a physical reactor to tune the shape and size of nanomaterials, and as a chemical microenvironment for the nucleation and growth of nanoconfined substances, resulting in unique material properties. This nanoconfinement effect has been extensively applied to synthesize materials for hydrogen storage, catalysis and separation for environmental protection. Here, we review methods to construct nanoconfined space in carbon materials, metal–organic frameworks, mesoporous silica, porous organic polymers and MXenes, a class of two-dimensional inorganic compounds. We discuss nanoconfinement for enhanced adsorption with focus on covering size and dispersion, crystallization and stability, confined water and coordination.

     

Microbial metabolism of chlorobiphenyls

Photochemical reactions induced by sunlight contribute to the overall chemistry of natural water systems in many ways. The degradation of pollutants, dissolution of iron and manganese sediments, cycling of trace metal nutrients, and reactions of aquatic nitrogen and oxygen species are some of the many processes having solar photolysis pathways. This paper reviews recent research concerned with photo‐decomposition of pollutants, photolysis of nitrite and nitrate, photosensitization by humic materials and the generation of reactive intermediates. In addition, background material is presented concerning the basic principles of photochemistry and the limited wavelength range of effective solar radiation.     

Graphene and its derivatives: synthesis,modifications, and applications in wastewater treatment

Graphene was discovered in 2004 and has attracted intensive interests because of its unique mechanical, electric, thermal, optical, and structural properties, which makes graphene a potential candidate for various applications. Graphene is being used as a composite or filler material with metals, metal oxides, and polymers for potential advanced applications in solar cells, lithium-ion batteries, photocatalysis and sensing. These applications depend upon the distinctive properties of graphene, which in turn depend on the adopted synthetic approach. This article reviews the recent developments in synthesis of graphene and related composite materials. The synthesis of graphene through exfoliation, epitaxial growth and direct growth via carbon source, and modification approaches by covalent and noncovalent methodologies are discussed. Graphene-based metal and metal oxide composites for the purification of wastewater using photolytic process are also presented.     

纳米银对鱼类的毒性效应研究进展

纳米银作为一种新兴的纳米材料,由于其独特的抗菌性能而被广泛应用于各种商业化产品中。广泛的应用增加了它进入环境尤其是水环境的机率,从而对鱼类等水生生物产生潜在毒性效应。因此,近年来陆续开展了关于纳米银对鱼类的毒理学研究。本文根据国内外文献查阅及分析,综述了纳米银的制备、特性、应用、释放情况以及近几年来纳米银对鱼类的毒理学研究进展,对今后进一步开展相关研究工作提供参考。     

Research progress on antimicrobial activities of sophorolipids and their synergistic effects with other antimicrobial substances北大核心CSCD

Sophorolipids (SLs), secondary metabolites of non-pathogenic yeasts, are glycolipid biosurfactants with wide applications. Research on the pharmaceutical activities of sophorolipids is important. In recent years, an increasing number of researchers have been interested in the antimicrobial activity of sophorolipids. In this study, the effects of sophorolipids on bacteria, fungi, and their biofilms were reviewed. Sophorolipids cause greater damage and better inhibition of gram-positive bacteria, and lactonic sophorolipids show stronger effects than acid sophorolipids. In addition, sophorolipids can disperse and destroy resistant biofilms, which are difficult to handle. Second, the synergistic effects of sophorolipids in combination with commonly used antibiotics and antimicrobial materials were reviewed. When sophorolipids and antibiotics are used together, the effective dosage of the antibiotics is significantly reduced. Sophorolipids can enhance the antimicrobial effects when used to synthesize or coat antimicrobial materials. Finally, we investigated the problems and development of the antimicrobial activities of sophorolipids, further expansion of the antimicrobial spectrum of sophorolipids, in-depth analysis of mechanisms of antimicrobial and synergistic effects, development and modification of new sophorolipids, and exploration of the water-solubility of sophorolipids. © 2022 Authors. All rights reserved.     

Environmental friendly food nano-packaging

Nanotechnology has found many applications in various fields. Nanotechnology promises many interesting changes for a better life, such as to improve health, wealth, products and quality of life, as well as reducing impact on the environment. Food nano-packaging is, however, still poorly developed despite several potentials to improve packaging materials and functions. This article reviews recent advances in food nano-packaging, including bio-based packaging, improved packaging, active packaging and smart packaging. Bio-based packaging, including biodegradable packaging and biocompatible packaging, is an alternative to actual packaging that uses non-degradable plastic polymers. Improved packaging focusses on nanomaterials that improve barrier properties, strength, flexibility and stability. Active packaging is based upon active nanomaterials such as antimicrobials and oxygen scavenging materials. Smart packaging refers to smart functions provided by nanomaterials, such as nanosensors and nanodevices that detect freshness or monitor changes in packaging integrity.     

微生物燃料电池处理含硫废水的研究进展

随着工业的快速发展及化石能源的大量消耗,迫切地需要寻找一种可持续发展的绿色节能技术来替代不可再生能源.微生物燃料电池(microbial fuel cell,MFC)以其处理难降解废水的同时产生电能的优势引起了人们的广泛关注,成为近几年的研究热点,而含硫废水一直以来是废水处理的难点.本文回顾了MFC生物除硫的发展历程,...