Experimental and field applications of nanotechnology for enhanced oil recovery purposes: A review

Pyrochlores belong to a numerous family of crystalline materials with a rich variety of technologically important functional properties and developed structural diversity of possible transformation...

Structural Diversity of Ordered Pyrochlores

A new member of fluorooxoborates, Li2Na0.9K0.1B5O8F2, was obtained in the sealed system, and single-crystal X-ray diffraction was used to determine its structure. It contains a three-dimensional framework stacking of [B5O8F2]3– layers extending into the ac plane. Detailed structural comparisons among all of the fluorine-containing alkali-metal borates suggest that the [B5O8F2]3– layer composed of the new fundamental building blocks B5O10F2 represents a new structure type of fluorooxoborate. The IR spectrum verifies its structural validity. The deep-ultraviolet spectral measurement shows that it has no obvious absorption in the range of 180–300 nm, and its cutoff edge is under 180 nm. In addition, theoretical calculations were done to help us understand its electronic structure and optical properties.

A Member of Fluorooxoborates: Li2Na0.9K0.1B5O8F2 with the Fundamental Building Block B5O10F2 and a Short Cutoff Edge.

Structure analysis and electronic properties of ATe4+0.5Te6+1.5-xM6+xO6 (A=Rb, Cs, M6+=Mo, W) solid solutions with β-pyrochlore structure

Membranes are a promising technology for bulk CO2 separation from natural gas mixtures due to their numerous advantages. Despite the numerous fundamental studies on creating better quality membrane efficiency, scaling up the research work for field testing requires huge efforts. The challenge is to ensure the stability of the membrane throughout the operation while maintaining its high performance. This review addresses the key challenges in the application of polymeric technology for CO2 separation, focusing on plasticization and aging. A brief introduction to the properties and limitations of the current commercial polymeric membrane is first deliberated. The effect of each plasticizer component in natural gas towards membrane performance and the relationship between operating conditions and the membrane efficiency are discussed in this review. The recent technological advancements and techniques to overcome the plasticization and aging issues covering polymer modification, high free-volume polymers, polymer blending and facilitated transport membranes (FTMs) have been highlighted. We also give our perspectives on a few main features of research related to polymeric membranes and the way forwards. Upcoming research must emphasize mixed gas with CO2 including minor condensable contaminants as per real natural gas, to determine the competitive sorption effect on CO2 permeability and membrane selectivity. The effects of pore blocking, plasticization and aging should be given particular attention to cater for large-scale applications.

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Recent Advances of Polymeric Membranes in Tackling Plasticization and Aging for Practical Industrial CO2/CH4 Applications—A Review

Photocatalytic properties of β-pyrochlore RbTe1.5W0.5O6 under visible-light irradiation

Single crystal structure and SHG of defect pyrochlores CsBVMoO6 (BV=Nb,Ta)

Crystal structure features of the mixed-valence tellurium β-pyrochlores: CsTe1.625W0.375O6 and RbTe1.5W0.5O6

Heterogeneous photocatalysis has been considered one of the most attractive alternative routes to transforming naturally abundant, clean, and sustainable solar energy into chemical energy. Nowadays, the most popular heterogeneous photocatalyst, titanium dioxide, has already found applications for water splitting to produce hydrogen and oxygen, for the degradation of organic pollutants, for air purification, and for the creation of self-cleaning coatings. However, TiO2 has a significant limitation: a large band gap (3.0–3.4 eV) that makes it impossible to use anything other than ultraviolet illumination to initiate photocatalytic processes. With a focus on efficient solar-energy utilization, the development of new photocatalysts that are sensitive to visible light is an important direction in the theory and practice of heterogeneous photocatalysis. In this regard, the use of metal–organic frameworks (MOFs) is an attractive route; they have emerged as an interesting class of materials for applications in photoreactions due to their flexible tunability in composition, structure, and functional properties, along with their facilitated adsorption towards chemicals and their efficient light absorption. Moreover, they can be composed with other semiconductors to produce heterojunctions (e.g., type-II, Z-scheme, and S-scheme), whose effectiveness in photogenerated charge separation has already been proven by many examples. The present critical review reports progress over the last 5 years in the preparation and activity of metal–organic framework-based heterojunction photocatalysts for the degradation of organic pollutants. © 2022 Society of Chemical Industry (SCI). 

D.G. Fukina

Papers

Structure analysis and electronic properties of ATe4+0.5Te6+1.5-xM6+xO6 (A=Rb, Cs, M6+=Mo, W) solid solutions with β-pyrochlore structure

Photocatalytic properties of β-pyrochlore RbTe1.5W0.5O6 under visible-light irradiation

Single crystal structure and SHG of defect pyrochlores CsBVMoO6 (BV=Nb,Ta)

Crystal structure features of the mixed-valence tellurium β-pyrochlores: CsTe1.625W0.375O6 and RbTe1.5W0.5O6

Metal–organic framework‐based heterojunction photocatalysts for organic pollutant degradation: design, construction, and performances