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Topic Review
Moist Rice Husk Smoldering for Silica Production
In order to assess the possibility of silica production via smoldering of moist rice husk, experiments of washed (moist) rice husk (7 kg with moisture content of 51%) in a newly designed smoldering apparatus was performed. The temperature inside the fuel bed during smoldering was recorded, and characteristics of ash were analyzed. Results showed that the highest temperature in the middle of the naturally piled fuel bed was about 560.0 °C, lower than those in most of combustors. Some volatiles from the lower part of the fuel bed adhere to its upper ash during piled smoldering. Silica content and specific surface area of ash from smoldering of washed (moist) rice husk were 86.4% and 84.9 m2/g, respectively.
  • 1.2K
  • 24 Jan 2022
Topic Review
MOFs for Mercury Detection
The advantages of metal organic frameworks (MOFs) are: existence of porosity to adsorb specific analyte, improved aqueous solubility, exceptional photophysical and chemical properties. MOFs are noted as exceptional candidates towards the detection and removal of specific analytes, particular for the detection/removal of environmental contaminants, such as heavy metal ions, toxic anions, hazardous gases, explosives, etc. Among heavy metal ions, mercury has been noted as a global hazard because of its high toxicity in the elemental (Hg0), divalent cationic (Hg2+), and methyl mercury (CH3Hg+) forms. To secure the environment and living organisms, many countries have imposed stringent regulations to monitor mercury at all costs. Regarding the detection/removal requirements of mercury, researchers have proposed and reported all kinds of MOFs-based luminescent/non-luminescent probes towards mercury.This review provides valuable information about the MOFs which have been engaged in detection and removal of elemental mercury and Hg2+ ions. Moreover, the involved mechanisms or adsorption isotherms related to sensors or removal studies are clarified for the readers. Finally, advantages and limitations of MOFs in mercury detection/removal are described together with future scopes.
  • 1.4K
  • 01 Jul 2021
Topic Review
MOFs Derivative One-Dimensional Nanofibers
MOFs are synthesized by the incorporation of both inorganic and organic units through template-guided assembly (e.g., mesh synthesis). The design flexibility of MOF in terms of highly variable geometry and functionality based on the choices of incorporated constituents has attracted increasing attentions from researchers in catalysis, energy, and electronics. The main advantage of MOFs in comparison with conventional porous materials is the achievement of specific structure and tunable porosity at the molecular level by adjusting both metal species and organic ligands. For instance, the typical porosity of MOFs is higher than 50% of the total solid volume while the surface area of MOFs generally ranges from 1000 to 10,000 m2 g−1, both superior to those found in conventional porous materials such as carbons and molecular sieve. 
  • 575
  • 23 Jun 2021
Topic Review
MOFs as ODS Catalysts
Catalytic oxidative desulfurization (ODS) of fuel oils is considered one of the most promising non-hydrodesulfurization technologies due to the advantages of mild reaction conditions, low cost and easy removal of aromatic sulfur compounds. Based on this reason, the preparation of highly efficient ODS catalysts has been a hot research topic in this field. Metal-organic frameworks (MOFs) have received much attention due to advantages such as abundant metal centers, high surface areas and varied pore structures, which are composed of secondary building units (SBUs) connected by organic linkers to form crystalline porous materials. Such materials possess both the rigidity of inorganic materials and the flexibility of organic materials. Moreover, rich metal centers in the structure of MOFs could be catalytic active sites for some chemical reactions.
  • 436
  • 19 Jan 2022
Topic Review
MOFs and COFs
Metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) are two innovative classes of porous coordination polymers. MOFs are three-dimensional materials made up of secondary building blocks comprised of metal ions/clusters and organic ligands whereas COFs are 2D or 3D highly porous organic solids made up by light elements (i.e., H, B, C, N, O). Both MOFs and COFs, being highly conjugated scaffolds, are very promising as photoactive materials for applications in photocatalysis and artificial photosynthesis because of their tunable electronic properties, high surface area, remarkable light and thermal stability, easy and relative low-cost synthesis, and structural versatility. 
  • 5.5K
  • 08 Dec 2020
Topic Review
MOF-Based Materials for Cathode Preparation in AZIBs
Aqueous zinc-ion batteries (AZIBs) are promising for large-scale energy storage systems due to their high safety, large capacity, cost-effectiveness, and environmental friendliness. Their commercialization is currently hindered by several challenging issues, including cathode degradation and zinc dendrite growth.
  • 317
  • 06 Apr 2023
Topic Review
MOF-based adsorbents for atmospheric emission
This topic focuses on the use of metal–organic frameworks (MOFs) for adsorbing gas species that are known to weaken the thermal self-regulation capacities of Earth’s atmosphere. A large section is dedicated to the adsorption of carbon dioxide, while another section is dedicated to the adsorption of other different gas typologies, whose emissions, for various reasons, represent a “wound” for Earth’s atmosphere. High emphasis is given to MOFs that have moved enough ahead in their development process to be currently considered as potentially usable in “real-world” (i.e., out-of-lab) adsorption processes. As a result, there is strong evidence of a wide gap between laboratory results and the industrial implementation of MOF-based adsorbents. Indeed, when a MOF that performs well in a specific process is commercially available in large quantities, economic observations still make designers tend toward more traditional adsorbents. Moreover, there are cases in which a specific MOF remarkably outperforms the currently employed adsorbents, but it is not industrially produced, thus strongly limiting its possibilities in large-scale use. To overcome such limitations, it is hoped that the chemical industry will be able to provide more and more mass-produced MOFs at increasingly competitive costs in the future.
  • 1.2K
  • 27 Aug 2020
Topic Review
Modulation of Enzyme Reactions on DNA Scaffold
Cells have developed intelligent systems to implement the complex and efficient enzyme cascade reactions via the strategies of organelles, bacterial microcompartments and enzyme complexes. The scaffolds such as the membrane or protein in the cell are believed to assist the co-localization of enzymes and enhance the enzymatic reactions. Inspired by nature, enzymes have been located on a wide variety of carriers, among which DNA scaffolds attract great interest for their programmability and addressability. Integrating these properties with the versatile DNA–protein conjugation methods enables the spatial arrangement of enzymes on the DNA scaffold with precise control over the interenzyme distance and enzyme stoichiometry.
  • 337
  • 09 Nov 2022
Topic Review
Modified Starch-Based Adhesives
Consumer trends towards environmentally friendly products are driving plastics industries to investigate more benign alternatives to petroleum-based polymers. In the case of adhesives, one possibility to achieve sustainable production is to use non-toxic, low-cost starches as biodegradable raw materials for adhesive production. While native starch contains only hydroxyl groups and has limited scope, chemically modified starch shows superior water resistance properties for adhesive applications. Esterified starches, starches with ester substituents, can be feasibly produced and utilized to prepare bio-based adhesives with improved water resistance. Syntheses of esterified starch materials can involve esterification, transesterification, alkylation, acetylation, succinylation, or enzymatic reactions.
  • 2.6K
  • 31 May 2022
Topic Review
Modified Nb-Si-Based Multi-Element Alloys
Nb-Si-based superalloys are considered as the most promising high-temperature structural material to replace the Ni-based superalloys. Unfortunately, the poor oxidation resistance is still a major obstacle to the application of Nb-Si-based alloys. Alloying is a promising method to overcome this problem.
  • 582
  • 22 Nov 2021
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