Classifications, properties, recent synthesis and applications of azo dyes.

Eutrophication of water bodies is a serious and widespread environmental problem. Achieving low levels of phosphate concentration to prevent eutrophication is one of the important goals of the wastewater engineering and surface water management. Meeting the increasingly stringent standards is feasible in using a phosphate-selective sorption system. This critical review discusses the most fundamental aspects of selective phosphate removal processes and highlights gains from the latest developments of phosphate-selective sorbents. Selective sorption of phosphate over other competing anions can be achieved based on their differences in acid-base properties, geometric shapes, and metal complexing abilities. Correspondingly, interaction mechanisms between the phosphate and sorbent are categorized as hydrogen bonding, shape complementarity, and inner-sphere complexation, and their representative sorbents are organic-functionalized materials, molecularly imprinted polymers, and metal-based materials, respectively. Dominating factors affecting the phosphate sorption performance of these sorbents are critically examined, along with a discussion of some overlooked facts regarding the development of high-performance sorbents for selective phosphate removal from water and wastewater.

Selective Phosphate Removal from Water and Wastewater using Sorption: Process Fundamentals and Removal Mechanisms.

Among the recent developments in metal-organic frameworks (MOFs), porous layered coordination polymers (CPs) have garnered attention due to their modular nature and tunable structures. These factors enable a number of properties and applications, including gas and guest sorption, storage and separation of gases and small molecules, catalysis, luminescence, sensing, magnetism, and energy storage and conversion. Among MOFs, two-dimensional (2D) compounds are also known as 2D CPs or 2D MOFs. Since the discovery of graphene in 2004, 2D materials have also been widely studied. Several 2D MOFs are suitable for exfoliation as ultrathin nanosheets similar to graphene and other 2D materials, making these layered structures useful and unique for various technological applications. Furthermore, these layered structures have fascinating topological networks and entanglements. This review provides an overview of different aspects of 2D MOF layered architectures such as topology, interpenetration, structural transformations, properties, and applications.

Two-Dimensional Metal-Organic Framework Materials: Synthesis, Structures, Properties and Applications.

CO2 electroreduction reaction (CO2RR) to fuels and feedstocks is an attractive route to close the anthropogenic carbon cycle and store renewable energy. The generation of more reduced chemicals, especially multicarbon oxygenate and hydrocarbon products (C2+) with higher energy density is highly desirable for industrial applications. However, selective conversion of CO2 to C2+ suffers from high overpotential, low reaction rate and low selectivity, and the process is extremely sensitive to the catalyst structure and electrolyte. Here we discuss strategies to achieve high C2+ selectivity through rational design of the catalyst and electrolyte. Current state-of-the-art catalysts, including Cu and Cu-bimetallic catalysts as well as alternative materials are considered. The importance of taking into consideration the dynamic evolution of the catalyst structure and composition are highlighted, focusing on findings extracted from in situ and operando characterizations. Additional theoretical insight into the reaction mechanisms underlying the improved C2+ selectivity of specific catalyst geometries/compositions in synergy with a well-chosen electrolyte are also provided.

Rational Catalyst and Electrolyte Design for Co2 Electroreduction Towards Multicarbon Products

Gallium oxide (Ga2O3) is an emerging wide bandgap semiconductor that has attracted a large amount of interest due to its ultra-large bandgap of 4.8 eV, a high breakdown field of 8 MV/cm, and high thermal stability. These properties enable Ga2O3 a promising material for a large range of applications, such as high power electronic devices and solar-blind ultraviolet (UV) photodetectors. In the past few years, a significant process has been made for the growth of high-quality bulk crystals and thin films and device optimizations for power electronics and solar blind UV detection. However, many challenges remain, including the difficulty in p-type doping, a large density of unintentional electron carriers and defects/impurities, and issues with the device process (contact, dielectrics, and surface passivation), and so on. The purpose of this article is to provide a timely review on the fundamental understanding of the semiconductor physics and chemistry of Ga2O3 in terms of electronic band structures, optical properties, and chemistry of defects and impurity doping. Recent progress and perspectives on epitaxial thin film growth, chemical and physical properties of defects and impurities, p-type doping, and ternary alloys with In2O3 and Al2O3 will be discussed.

Recent progress on the electronic structure, defect, and doping properties of Ga2O3

High quality CVD single crystal diamonds grown on nanorods patterned diamond seed

Synthesis, aggregation-induced emission and application as chemosensor for explosives of a 1,10-phenanthroline derivative and its rhenium(I) carbonyl complex having triphenylamino and thienyl donors

The spontaneous emission (SE) of InGaN/GaN quantum well (QW) structure with silver(Ag) coated on the n-GaN layer has been investigated by using six-by-six K-P method taking into account the electron-hole band structures, the photon density of states of surface plasmon polariton (SPP), and the evanescent fields of SPP. The SE into SPP mode can be remarkably enhanced due to the increase of electron-hole pairs near the Ag by modulating the InGaN/GaN QW structure or increasing the carrier injection. However, the ratio between the total SE rates into SPP mode and free space will approach to saturation or slightly decrease for the optimized structures with various distances between Ag film and QW layer at a high injection carrier density. Furthermore, the Ga-face QW structure has a higher SE rate than the N-face QW structure due to the overlap region of electron-hole pairs nearer to the Ag film.

Effect of the band structure of InGaN/GaN quantum well on the surface plasmon enhanced light-emitting diodes

InxGa1−xN alloys with low indium composition x in the range 0.13 ≤ x ≤ 0.23 are systematically studied mainly based on a Raman scattering technique. Scanning electron microscopy and x-ray diffraction results show that our samples can be divided into two groups: pseudomorphic (0.13 ≤ x ≤ 0.16) and relaxed (0.18 ≤ x ≤ 0.23). The prominent enhancement of A1 longitudinal-optical (LO) mode is found with 325 nm laser excitation. For pseudomorphic samples, the frequencies of A1 (LO) phonons agree well with the theoretical predictions, which verifies that the samples are fully strained. For relaxed InxGa1−xN samples, a linear dependence of the A1 (LO) mode frequency is obtained: Ω0(x) = (740.8 ± 3.3) − (143.1 ± 16.0)x, which is the evidence of one-mode behavior in InxGa1−xN ternary alloys. Residual strains in these partially relaxed samples are also evaluated.

http://iopscience.iop.org/article/10.1088/0256-307X/29/2/027803/pdf

Tao Tao

Papers

High quality CVD single crystal diamonds grown on nanorods patterned diamond seed

Synthesis, aggregation-induced emission and application as chemosensor for explosives of a 1,10-phenanthroline derivative and its rhenium(I) carbonyl complex having triphenylamino and thienyl donors

Effect of the band structure of InGaN/GaN quantum well on the surface plasmon enhanced light-emitting diodes

Raman Scattering Study of In x Ga 1 −x N Alloys with Low Indium Compositions

Nanomaterials for fluorescent detection of curcumin.