scholarly journals P=O Functionalized Black Phosphorus/1T-WS2 Nanocomposite High Efficiency Hybrid Photocatalyst for Air/Water Pollutant Degradation

2022 ◽  
Vol 23 (2) ◽  
pp. 733
Author(s):  
Rak-Hyun Jeong ◽  
Ji-Won Lee ◽  
Dong-In Kim ◽  
Seong Park ◽  
Ju-Won Yang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Clean Energy ◽  
Two Dimensions ◽  
Black Phosphorus ◽  
Composite Catalyst ◽  
Bandgap Energy ◽  
Oxygen Plasma Treatment ◽  
Layer By Layer ◽  
High Concentration ◽  
Catalytic Material

Research on layered two-dimensional (2D) materials is at the forefront of material science. Because 2D materialshave variousplate shapes, there is a great deal of research on the layer-by-layer-type junction structure. In this study, we designed a composite catalyst with a dimension lower than two dimensions and with catalysts that canbe combined so that the band structures can be designed to suit various applications and cover for each other’s disadvantages. Among transition metal dichalcogenides, 1T-WS2 can be a promising catalytic material because of its unique electrical properties. Black phosphorus with properly controlled surface oxidation can act as a redox functional group. We synthesized black phosphorus that was properly surface oxidized by oxygen plasma treatment and made a catalyst for water quality improvement through composite with 1T-WS2. This photocatalytic activity was highly efficient such that the reaction rate constant k was 10.31×10−2 min−1. In addition, a high-concentration methylene blue solution (20 ppm) was rapidly decomposed after more than 10 cycles and showed photo stability. Designing and fabricating bandgap energy-matching nanocomposite photocatalysts could provide a fundamental direction in solving the future’s clean energy problem.

scholarly journals Near quantitative synthesis of urea macrocycles enabled by bulky N-substituent

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yingfeng Yang ◽  
Hanze Ying ◽  
Zhixia Li ◽  
Jiang Wang ◽  
Yingying Chen ◽  
...  
Keyword(s):  
High Efficiency ◽  
Molecular Structures ◽  
High Yield ◽  
Kinetic Control ◽  
High Concentration ◽  
Weak Association ◽  
Quantitative Synthesis ◽  
Thermodynamic Stabilization ◽  
Discrete Structures ◽  
Very High

AbstractMacrocycles are unique molecular structures extensively used in the design of catalysts, therapeutics and supramolecular assemblies. Among all reactions reported to date, systems that can produce macrocycles in high yield under high reaction concentrations are rare. Here we report the use of dynamic hindered urea bond (HUB) for the construction of urea macrocycles with very high efficiency. Mixing of equal molar diisocyanate and hindered diamine leads to formation of macrocycles with discrete structures in nearly quantitative yields under high concentration of reactants. The bulky N-tert-butyl plays key roles to facilitate the formation of macrocycles, providing not only the kinetic control due to the formation of the cyclization-promoting cis C = O/tert-butyl conformation, but also possibly the thermodynamic stabilization of macrocycles with weak association interactions. The bulky N-tert-butyl can be readily removed by acid to eliminate the dynamicity of HUB and stabilize the macrocycle structures.

scholarly journals Engineering of TiO2 or ZnO—Graphene Oxide Nanoheterojunctions for Hybrid Solar Cells Devices

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 75
Author(s):  
Duarte Carreira ◽  
Paulo A. Ribeiro ◽  
Maria Raposo ◽  
Susana Sério
Keyword(s):  
Graphene Oxide ◽  
Solar Cells ◽  
Fossil Fuels ◽  
Electrical Characterization ◽  
Modern Society ◽  
Clean Energy ◽  
Zno Films ◽  
Layer By Layer ◽  
Glass Substrates ◽  
Rc Circuit

It is currently of huge importance to find alternatives to fossil fuels to produce clean energy and to ensure the energy demands of modern society. In the present work, two types of hybrid solar cell devices were developed and characterized. The photoactive layers of the hybrid heterojunctions comprise poly (allylamine chloride) (PAH) and graphene oxide (GO) and TiO2 or ZnO films, which were deposited using the layer-by-layer technique and DC-reactive magnetron sputtering, respectively, onto fluorine-doped tin oxide (FTO)-coated glass substrates. Scanning electron microscopy evidenced a homogeneous inorganic layer, the surface morphology of which was dependent on the number of organic bilayers. The electrical characterization pointed out that FTO/(PAH/GO)50/TiO2/Al, FTO/(PAH/GO)30/ZnO/Al, and FTO/(PAH/GO)50/ZnO/Al architectures were the only ones to exhibit a diode behavior, and the last one experienced a decrease in current in a low-humidity environment. The (PAH/GO)20 impedance spectroscopy study further revealed the typical impedance of a parallel RC circuit for a dry environment, whereas in a humid environment, it approached the impedance of a series of three parallel RC circuits, indicating that water and oxygen contribute to other conduction processes. Finally, the achieved devices should be encapsulated to work successfully as solar cells.

Solar Thermophotovoltaic Converters Based on Tungsten Emitters

2006 ◽  
Vol 129 (3) ◽  
pp. 298-303 ◽  
Author(s):  
V. M. Andreev ◽  
A. S. Vlasov ◽  
V. P. Khvostikov ◽  
O. A. Khvostikova ◽  
P. Y. Gazaryan ◽  
...  
Keyword(s):  
Band Gap ◽  
High Efficiency ◽  
Radiation Spectrum ◽  
Cost Effective ◽  
Fresnel Lens ◽  
Photocurrent Density ◽  
Back Side ◽  
High Concentration ◽  
Emitter System ◽  
Solar Powered

Results of a solar thermophotovoltaic (STPV) system study are reported. Modeling of the STPV module performance and the analysis of various parameters influencing the system are presented. The ways for the STPV system efficiency to increase and their magnitude are considered such as: improvement of the emitter radiation selectivity and application of selective filters for better matching the emitter radiation spectrum and cell photoresponse; application of the cells with a back side reflector for recycling the sub-band gap photons; and development of low-band gap tandem TPV cells for better utilization of the radiation spectrum. Sunlight concentrator and STPV modules were designed, fabricated, and tested under indoor and outdoor conditions. A cost-effective sunlight concentrator with Fresnel lens was developed as a primary concentrator and a secondary quartz meniscus lens ensured the high concentration ratio of ∼4000×, which is necessary for achieving the high efficiency of the concentrator–emitter system owing to trap escaping radiation. Several types of STPV modules have been developed and tested under concentrated sunlight. Photocurrent density of 4.5A∕cm2 was registered in a photoreceiver based on 1×1cm2GaSb cells under a solar powered tungsten emitter.

Amphiphilic SiO2 hybrid aerogel: an effective absorbent for emulsified wastewater

2017 ◽  
Vol 5 (25) ◽  
pp. 12856-12862 ◽  
Author(s):  
Xiang-Dong Gao ◽  
Yu-Di Huang ◽  
Tong-Tong Zhang ◽  
Yong-Qing Wu ◽  
Xiao-Min Li
Keyword(s):  
High Efficiency ◽  
High Concentration ◽  
Hybrid Aerogel

Amphiphilic SiO2–chitosan hybrid aerogel demonstrates rapid and high-efficiency absorption of a high-concentration polyacrylic emulsion or machining emulsified wastewater.

scholarly journals Safe water for all: A nature-based approach for cyanotoxin elimination from potable water

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Sylvia Soldatou ◽  
Anjali Jaykumar ◽  
Abeysiri H.A.S.N ◽  
Pathmalal M. Manage ◽  
Ondřej Mašek ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Kidney Disease ◽  
Crop Residues ◽  
Clean Energy ◽  
Cyanobacterial Blooms ◽  
Sri Lankan ◽  
High Concentration ◽  
Safe Water ◽  
Key Factor ◽  
Coconut Shells

Cyanobacterial blooms are a serious threat to public health and water quality due to the production of cyanotoxins as a result of nutrient pollution from industry, agriculture, domestic waste as well as global warming. The microcystins (MCs) are the most abundant cyanotoxins consisting of >200 analogues causing both acute and chronic toxicity, sometimes resulting in death. In Asian countries, such as Sri Lanka, reports of kidney disease are constantly increasing. Although no direct link between metal and pesticide contamination in water and kidney disease has been found, high concentration of cyanobacteria cells in drinking water wells implies that the nephrotoxic effects of cyanotoxins might play a key factor in the reports of Chronic Kidney Disease of unknown aetiology (CKDu) in Sri Lanka. Therefore, we propose a nature-based approach for water treatment which will study the hypotheses that cyanotoxins can cause CKDu. Sri Lankan bacterial isolates (Alcaligens sp., Roseateles sp., Bacillus sp., and Micrococcus sp.) known to degrade microcystins, were used to form biofilm on biochar from Sri Lankan crop residues, such as coconut shells. The immobilisation of the microbes was assessed via a high-throughput colourimetric assay, followed by monitoring the biodegradation rate of microcystins when added to the immobilised cultures. Biodegradation products were analysed and identified through molecular networking and quantified via LC-MS/MS. Ultimately, this project will provide safe water in line with UN Sustainable Development Goal 6.1 as well contributing in sustainable goals 7 (Affordable and Clean Energy), 11 (Sustainable Cities and Communities) and 12 (Responsible Production and Consumption).

In Situ Thermal Response Test Methods And Practices

2011 ◽  
Vol 347-353 ◽  
pp. 3087-3092
Author(s):  
Qiang Li ◽  
You Hong Sun ◽  
Xin Fang
Keyword(s):  
High Efficiency ◽  
Thermal Response ◽  
Clean Energy ◽  
Heat Pumps ◽  
Testing Equipment ◽  
Physical Parameters ◽  
Geothermal Wells ◽  
Response Testing ◽  
Thermal Physical Parameters

Abstract. As a high efficiency, low consumption and clean energy, ground source heat pump technology has been pay more and more attention, the number of installation of system is growing rapidly. However, the use of geothermal resources is still extensive at this stage. Effective methods are pure in obtaining thermal physical parameters of geothermal wells around. In-situ thermal response testing is close to the real use of heat pumps, when injecting in or extracting heat from geothermal wells, the testing equipment will collect data, and then thermal physical parameters will be accurately calculate. This paper introduce a thermal response testing equipment, the equipment will add a constant cold or heat to geothermal well, circulating heat flow and pressure data is collected as well as temperature. And then thermal physical parameters of formation and heat exchanging performance are calculated.

Black phosphorus quantum dots as dual-functional electron-selective materials for efficient plastic perovskite solar cells

2018 ◽  
Vol 6 (19) ◽  
pp. 8886-8894 ◽  
Author(s):  
Nianqing Fu ◽  
Chun Huang ◽  
Peng Lin ◽  
Mingshan Zhu ◽  
Tao Li ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
High Efficiency ◽  
Perovskite Solar Cells ◽  
Black Phosphorus ◽  
Selective Layer ◽  
Dual Functional ◽  
Black Phosphorus Quantum Dots ◽  
Electron Extraction

Dual-functional black phosphorus quantum dot electron selective layer was designed for plastic perovskite solar cells. The efficient electron extraction and improved perovskite film quality contributed to the reasonably high efficiency.

Electron Acceleration in Collapsing Magnetic Traps during the Solar Flare on July 19, 2012: Observations and Models

2017 ◽  
Vol 13 (S335) ◽  
pp. 90-93
Author(s):  
P. A. Gritsyk ◽  
B. V. Somov
Keyword(s):  
Point Source ◽  
Solar Flares ◽  
High Efficiency ◽  
Reverse Current ◽  
Electron Acceleration ◽  
Thick Target ◽  
Two Dimensions ◽  
Magnetic Traps ◽  
Thin Target ◽  
X Ray

AbstractUsing the appropriate kinetic equation, we considered the problem of propagation of accelerated electrons into the solar corona and chromosphere. Its analytical solution was used for modelling the M7.7 class limb flare occurred on July 19, 2012. Coronal above-the-loop-top hard X-Ray source was interpreted in the thin-target approximation, the foot-point source - in the thick-target approximation with account of the reverse-current electric field. For the foot-point source we found a good accordance with the RHESSI observations. For the coronal source we also got very accurate estimate of the power-law spectral index, but significant differences between the modelled and observed hard X-ray intensities were noticed. The last discrepancy was solved by adding the coronal magnetic trap model to the thin target model. The former one implies that the trap collapses in two dimensions, locks and accelerates particles inside itself. In our report, we confirm an existence and high efficiency of the electron acceleration in collapsing magnetic traps during solar flares. Our new results represent (e.g. for RHESSI observations) the theoretical prediction of the double step particle acceleration in solar flares, when the first step is the acceleration in reconnection area and the second one – the acceleration in coronal trap.

Layer-by-layer Assembly Polyethylenimine/phytic Acid Coating With Gradient Structure for High-Efficiency and Durable Flame Retardant Cotton Fabric With Good Physical and Mechanical Properties

2021 ◽  
Author(s):  
Xinhua Liu ◽  
Hailong Liu ◽  
Yinchun Fang
Keyword(s):  
Physical Properties ◽  
Flame Retardant ◽  
Cotton Fabric ◽  
High Efficiency ◽  
Cotton Fabrics ◽  
Gradient Structure ◽  
Layer By Layer ◽  
Assembly Method ◽  
Lbl Assembly ◽  
Coated Cotton

Abstract In this study, intumescent flame retardant coating of polyethylenimine/phytic acid (PEI/PA) with gradient structure was constructed on cotton fabric through facile layer-by-layer (LBL) assembly method. The LOI value of coated cotton fabric reached over 40% indicating excellent flame retardancy. Reasonable controlling the LBL assembly process of PEI/PA coating brought less influence to the physical properties of cotton fabrics. And the coated cotton fabric revealed good flame retardant washing durability. Thermogravimetric analysis results of coated cotton fabrics showed that PEI/PA flame retardant coating changed the thermal decomposition process and promoted char formation revealing the obviously condensed phase flame retardant action. SEM images of char residues revealed that PEI/PA flame retardant coating promoted to form the intumescent flame retardant (IFR) char layer showing obvious IFR action. This research provides novel strategy for the development of high-efficiency flame retardant cotton fabric with good durability and physical properties using simple LBL assembly method.

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