scholarly journals Metal Chalcogenides Based Heterojunctions and Novel Nanostructures for Photocatalytic Hydrogen Evolution

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 89 ◽  
Author(s):  
Jian Li ◽  
Pablo Jiménez-Calvo ◽  
Erwan Paineau ◽  
Mohamed Nawfal Ghazzal
Keyword(s):  
High Performance ◽  
Rational Design ◽  
Individual Component ◽  
Chemical Properties ◽  
Charge Carriers ◽  
Metal Chalcogenides ◽  
Physico Chemical ◽  
Efficient Charge ◽  
Periodical Structure ◽  
Hollow Cylinders

The photo-conversion efficiency is a key issue in the development of new photocatalysts for solar light driven water splitting applications. In recent years, different engineering strategies have been proposed to improve the photogeneration and the lifetime of charge carriers in nanostructured photocatalysts. In particular, the rational design of heterojunctions composites to obtain peculiar physico-chemical properties has achieved more efficient charge carriers formation and separation in comparison to their individual component materials. In this review, the recent progress of sulfide-based heterojunctions and novel nanostructures such as core-shell structure, periodical structure, and hollow cylinders is summarized. Some new perspectives of opportunities and challenges in fabricating high-performance photocatalysts are also discussed.

Preparation and Photocatalytic Activity of Mixed Phase Anatase/rutile TiO2 Nanoparticles for Phenol Degradation

2014 ◽  
Vol 70 (2) ◽  
Author(s):  
Mohamad Azuwa Mohamed ◽  
Wan Norharyati Wan Salleh ◽  
Juhana Jaafar ◽  
Norhaniza Yusof
Keyword(s):  
Photocatalytic Activity ◽  
Tio2 Nanoparticles ◽  
High Performance ◽  
Sol Gel ◽  
Phenol Degradation ◽  
Chemical Properties ◽  
Mixed Phase ◽  
Rutile Tio2 ◽  
Physico Chemical ◽  
Degussa P25

The evolution of desirable physico-chemical properties in high performance photocatalyst materials involves steps that must be carefully designed, controlled, and optimized. This study investigated the role of key parameter in the preparation and photocatalytic activity analysis of the mixed phase of anatase/rutile TiO2 nanoparticles, prepared via sol-gel method containing titanium-n-butoxide Ti(OBu)4 as a precursor material, nitric acid as catalyst, and isopropanol as solvent. The prepared TiO2 nanoparticles were characterized by means of XRD, SEM, and BET analyses, and UV-Vis-NIR spectroscopy. The results indicated that the calcination temperature play an important role in the physico-chemical properties and photocatalytic activity of the resulting TiO2 nanoparticles. Different calcination temperatures would result in different composition of anatase and rutile. The photocatalytic activity of the prepared mixed phase of anatase/rutile TiO2 nanoparticles was measured by photodegradation of 50 ppm phenol in an aqueous solution. The commercial anatase from Sigma-Aldrich and Degussa P25 were used for comparison purpose. The mixed phase of anatase/rutile TiO2 nanoparticles (consists of 38.3% anatase and 61.7% rutile) that was prepared at 400°C exhibited the highest photocatalytic activity of 84.88% degradation of phenol. The result was comparable with photocatalytic activity demonstrated by Degussa P25 by 1.54% difference in phenol degradation. The results also suggested that the mixed phase of anatase/rutile TiO2 nanoparticles is a promising candidate for the phenol degradation process. The high performance of photocatalyst materials may be obtained by adopting a judicious combination of anatase/rutile and optimized calcination conditions.

Comparative Study of Physico-Chemical Properties of Pure Polyurethane and Polyurethane Based on Castor Oil

2014 ◽  
Vol 983 ◽  
pp. 39-43
Author(s):  
M. A. Alaa ◽  
Kamal Yusoh ◽  
S.F. Hasany
Keyword(s):  
Castor Oil ◽  
High Performance ◽  
In Situ Polymerization ◽  
Chemical Properties ◽  
Strength Properties ◽  
Hydroxyl Group ◽  
Physico Chemical ◽  
Analysis Technique ◽  
Hydrophobic Nature ◽  
Poly Propylene

Petroleum based polyurethanes are contributing major portions in the world requirement. To overcome the environmental issues and price adaptability, there is always a massive demand of utilization of renewable resources for polyurethane synthesis with comparable physico-chemical properties. Castor oil is the only major natural vegetable oil that contains a hydroxyl group (-OH) and unsaturated double bonds (C=C) in its organic chain and therefore can be employed with or without modification due to the excellent properties derived from the hydrophobic nature of triglycerides. In this study, physico-chemical properties of high performance polyurethane synthesized from Poly propylene glycol (PPG) in comparison with a combination of PPG and Castor oil (a renewable source), by in situ polymerization technique has been studied. The variations in properties of both types of polyurethanes are evaluated by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Thermogravimetric analysis technique (TGA). Tensile strength properties were investigated by Film Tensile testing equipment. Results indicated the presence of large-CH stretching in castor oil mixed polyurethane with a larger oxidative thermal stability, over a pure PPG polyurethanes. Tensile properties were found almost comparable in pure and mixed polymers, which signify the usage of mixed polymer in coming future, to overcome the environmental and economical crisis in polyurethanes synthesis.

scholarly journals Wet-chemical method for the metallization of a para-aramid filament yarn wound on a cylindrical dyeing package

2016 ◽  
Vol 87 (10) ◽  
pp. 1192-1202 ◽  
Author(s):  
Toty Onggar ◽  
Gosbert Amrhein ◽  
Anwar Abdkader ◽  
Rolf-Dieter Hund ◽  
Chokri Cherif
Keyword(s):  
Composite Materials ◽  
High Performance ◽  
Glass Fibers ◽  
Chemical Properties ◽  
Filament Yarn ◽  
Silver Layer ◽  
Physico Chemical ◽  
Before And After ◽  
Physical Examinations ◽  
Wet Chemical

High-performance yarns such as aramid fibers are nowadays used to reinforce composite materials due to their advantageous physico-chemical properties and their low weight. They are also resistant to heat and fire. Para-aramid filament yarns (p-AFs) wound on a cylindrical dyeing package have been silvered successfully by means of a newly developed wet-chemical filament yarn metallization process on a laboratory scale. The surface morphology of untreated and silvered p-AF was determined by means of scanning electron microscopy. The chemical structure of the surfaces (contents of carbon, oxygen, nitrogen and silver) was determined by means of energy-dispersive X-ray spectroscopy (EDX). The eliminated and newly formed groups of p-AF before and after silvering were detected by infrared spectroscopy (Fourier transform—attenuated total reflectance). After metallization, the silver layer thickness, the mass-related silver content and washing and rubbing fastness were assessed. Furthermore, textile-physical examinations concerning Young's modulus, elongation at break and electrical conductivity were performed. Subsequently, the electrically conductive p-AFs were integrated in thermoset composite materials reinforced by glass fibers and para-aramid.

Bioinspired tailoring of nanoarchitectured nickel sulfide@nickel permeated carbon composite as highly durable and redox chemistry enabled battery-type electrode for hybrid supercapacitors

2021 ◽  
Author(s):  
Mohan Reddy Pallavolu ◽  
Ramesh Reddy N ◽  
Hemachandra Rao Goli ◽  
Arghya Narayan Banerjee ◽  
G. Rajasekhara Reddy ◽  
...  
Keyword(s):  
High Performance ◽  
Rational Design ◽  
Electrode Materials ◽  
Cost Effective ◽  
Carbon Composite ◽  
Metal Chalcogenides ◽  
Energy Storage Devices ◽  
Active Electrode ◽  
Storage Devices ◽  
Hybrid Supercapacitors

Rational design of highly conductive and redox-active electrode materials composed of metal chalcogenides and carbon composites has attracted promising attention for the development of high-performance energy storage devices. Herein, cost-effective...

ChemInform Abstract: Physico-Chemical Properties of Micro-Spherical Silica Gel for High- Performance Liquid Chromatography.

ChemInform ◽  
2010 ◽  
Vol 24 (25) ◽  
pp. no-no
Author(s):  
N. V. ZHURAVLEVA ◽  
K. I. SAKODYNSKII ◽  
M. A. KUKLINA ◽  
V. M. KUKLIN ◽  
N. N. SUKHANOV
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Silica Gel ◽  
High Performance ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Spherical Silica

scholarly journals Positional Effect of π-extension in Triple Helicenes

2021 ◽  
Author(s):  
Alex van der Ham ◽  
Thomas Hansen ◽  
Hermen S. Overkleeft ◽  
Trevor A. Hamlin ◽  
Dmitri V. Filippov ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rational Design ◽  
Marked Effect ◽  
Chemical Properties ◽  
Spectroscopic Properties ◽  
Positional Effect ◽  
Physico Chemical ◽  
Optical Applications ◽  
High Level ◽  
Vt Nmr

The targeted application of multiple helicenes in photo-optical applications requires their rational design. Toward this goal, we report on the synthesis of pyrene-based triple helicene 1 and investigate the positional effect of extension of the π-conjugated system on the photo-chemical and chiro-optical properties of triple helicenes. The conformational and aggregatory behavior of 1 were studied both experimentally using VT NMR spectroscopy and computationally using high-level DFT computations. Although π-extension was observed to have a marked effect on the spectroscopic properties of triple helicenes, comparison with other known π-extended helicenes reveals that the position at which π-extension is introduced is only of nominal importance. Our results thus suggest that the presence of a particular helicene motif is dominant in dictating the physico-chemical properties of triple helicenes.

Effect of γ-Radiation on Physico-Chemical Properties of Lanthanum Cobaltate (LaCoO3)

1989 ◽  
Vol 157 ◽  
Author(s):  
B. Srinivas ◽  
V.R.S. Rao ◽  
J.C. Kuriacose
Keyword(s):  
Electrical Conductivity ◽  
Metal Content ◽  
Chemical Properties ◽  
Catalytic Decomposition ◽  
Charge Carriers ◽  
Surface Cracks ◽  
Γ Radiation ◽  
Surface Corrosion ◽  
Chemisorbed Oxygen ◽  
Physico Chemical

ABSTRACTThe influence of γ-radiation on LaCoO3, for the catalytic decomposition of H2O2 has been studied. ESR and XPS studies of γ-irradiated LaCoO3, snowed, the formation of chemisorbed oxygen (O2) and reduction of Co2+ to Co . γ-irradia]:ion of LaCoO3. causes a decrease in electrical conductivity due to the trapping of charge carriers by the chemisorbed oxygen. SEM photographs of the Y-irradiated sample pellets reveal surface cracks and surface corrosion due to the diffusion of transition metal to surface. The enhancement in the catalytic activity for the decomposition of H2O2 is found to be directly proportional to the reduced metal content.

scholarly journals Physico-Chemical Properties of Sacha Inchi (Plukenetia volubilis L.) Seed Oil from Vietnam

2019 ◽  
Vol 32 (2) ◽  
pp. 335-338 ◽  
Author(s):  
Huynh Cang Mai ◽  
Duy Chinh Nguyen ◽  
Nguyen Phu Thuong Nhan ◽  
Long Giang Bach
Keyword(s):  
High Performance ◽  
Seed Oil ◽  
Essential Fatty Acids ◽  
Chemical Properties ◽  
Acid Value ◽  
Chemical Characteristics ◽  
Flame Ionization ◽  
Physico Chemical ◽  
Plukenetia Volubilis ◽  
Sacha Inchi

Sacha inchi (Plukenetia volubilis L.) seed oil was studied for physico-chemical characteristics and chemical composition. Through gas chromatography-flame ionization (GC-FID) process, the fatty acid composition in the oil was analyzed, revealing that the oil is rich in linoleic acid (42.62 %), linolenic acid (36.32 %) and oleic acid (11.64 %). The tocopherol level in the oil was also high (7.7 ± 0.005 mg/Kg), revealed by high-performance liquid chromatography/ultraviolet-visible detector (HPLC/UV-VIS). The physico-chemical properties of the oil were also examined, including viscosity (88-92 cP), acid value (2.05 ± 0.005 mg KOH/g), saponification content (183.5 ± 1.45 mg KOH/g) and iodine value (192.4 ± 1.55 g I2/100 g). The results also indicated that sacha inchi is a health beneficial oil due to the high contents of essential fatty acids (ω-3, ω-6 and ω-9).

scholarly journals Positional Effect of π-extension in Triple Helicenes

2021 ◽  
Author(s):  
Alex van der Ham ◽  
Hermen S. Overkleeft ◽  
Dmitri V. Filippov ◽  
Grégory F. Schneider
Keyword(s):  
Optical Properties ◽  
Nmr Spectroscopy ◽  
Rational Design ◽  
Marked Effect ◽  
Chemical Properties ◽  
Positional Effect ◽  
Physico Chemical ◽  
Optical Applications ◽  
High Level ◽  
Vt Nmr

Application of multiple helicenes in photo‐optical applications requires their rational design. We therefore here report on the synthesis of pyrene‐based triple helicene 1, to study the positional effect of extension of the π‐conjugated system on the photo‐chemical and chiro‐optical properties of triple helicenes. The conformational and aggregatory behavior of 1 were studied both experimentally using VT NMR spectroscopy and computationally using high‐level DFT computations. Although π‐extension was observed to have a marked effect on the spectroscopy properties of triple helicenes, comparison with other known π‐extended helicenes reveals that the position at which π‐extension is introduced is only of nominal importance. Our results thus suggest that the presence of a particular helicene motive is dominant in dictating the physico‐chemical properties of triple helicenes.

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