scholarly journals Controlled Synthesis of CuS and Cu9S5 and Their Application in the Photocatalytic Mineralization of Tetracycline

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 899
Author(s):  
Murendeni P. Ravele ◽  
Opeyemi A. Oyewo ◽  
Damian C. Onwudiwe
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
X Ray ◽  
Copper Sulfides ◽  
Transmission Electron ◽  
Single Source Precursor ◽  
Pure Phase ◽  
Pure Phases

Pure-phase Cu2−xS (x = 1, 0.2) nanoparticles have been synthesized by the thermal decomposition of copper(II) dithiocarbamate as a single-source precursor in oleylamine as a capping agent. The compositions of the Cu2−xS nanocrystals varied from CuS (covellite) through the mixture of phases (CuS and Cu7.2S4) to Cu9S5 (digenite) by simply varying the temperature of synthesis. The crystallinity and morphology of the copper sulfides were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), which showed pure phases at low (120 °C) and high (220 °C) temperatures and a mixture of phases at intermediate temperatures (150 and 180 °C). Covellite was of a spherical morphology, while digenite was rod shaped. The optical properties of these nanocrystals were characterized by UV−vis–NIR and photoluminescence spectroscopies. Both samples had very similar absorption spectra but distinguishable fluorescence properties and exhibited a blue shift in their band gap energies compared to bulk Cu2−xS. The pure phases were used as catalysts for the photocatalytic degradation of tetracycline (TC) under visible-light irradiation. The results demonstrated that the photocatalytic activity of the digenite phase exhibited higher catalytic degradation of 98.5% compared to the covellite phase, which showed 88% degradation within the 120 min reaction time using 80 mg of the catalysts. The higher degradation efficiency achieved with the digenite phase was attributed to its higher absorption of the visible light compared to covellite.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

scholarly journals Photocatalytic Degradation of Tetracycline in Aqueous Solution Using Copper Sulfide Nanoparticles

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1238
Author(s):  
Murendeni P. Ravele ◽  
Opeyemi A. Oyewo ◽  
Sam Ramaila ◽  
Lydia Mavuru ◽  
Damian C. Onwudiwe
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Copper Sulfide ◽  
Degradation Rate ◽  
Light Exposure ◽  
Reaction System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pure Phase

In this paper, spherical-shaped pure phase djurleite (Cu31S16) and roxbyite (Cu7S4) nanoparticles were prepared by a solvothermal decomposition of copper(II) dithiocarbamate complex in dodecanthiol (DDT). The reaction temperature was used to control the phases of the samples, which were represented as Cu31S16 (120 °C), Cu31S16 (150 °C), Cu7S4 (220 °C), and Cu7S4 (250 °C) and were characterized by using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), and absorption spectroscopy. The samples were used as photocatalysts for the degradation of tetracycline (TC) under visible light irradiation. The results of the study showed that Cu7S4 (250 °C) exhibited the best activity in the reaction system with the TC degradation rate of up to 99% within 120 min of light exposure, while the Cu31S16 (120 °C) system was only 46.5% at the same reaction condition. In general, roxbyite Cu7S4 (250 °C) could be considered as a potential catalyst for the degradation of TC in solution.

Ag2O/ZnO Heterostructures with Enhanced Photocatalytic Activity

2021 ◽  
Vol 1035 ◽  
pp. 1043-1049
Author(s):  
Di Xiang ◽  
Chang Long Shao
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Environmental Remediation ◽  
Organic Dyes ◽  
Light Irradiation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
P Type

A simple route has been developed for the synthesis of Ag2O/ZnO heterostructures and the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and photoluminescence (PL) spectroscopy analysis. Considering the porous structure of Ag2O/ZnO, the photocatalytic degradation for the organic dyes, such as eosin red (ER), methyl orange (MO), methylene blue (MB) and rhodamine B (RhB), under visible light irradiation was investigated in detail. Noticeably, Ag2O/ZnO just took 40 min to degrade 96 % MB. The rate of degradation using the Ag2O/ZnO heterostructures was 2.3 times faster than that of the bare porous ZnO nanospheres under visible light irradiation due to that the recombination of the photogenerated charge was inhibited greatly in the p-type Ag2O and n-type ZnO semiconductor. So the Ag2O/ZnO heterostuctures showed the potential application on environmental remediation.

scholarly journals Shape Tuning of Magnetite Nanoparticles Obtained by Hydrothermal Synthesis: Effect of Temperature

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Nayely Torres-Gómez ◽  
Osvaldo Nava ◽  
Liliana Argueta-Figueroa ◽  
René García-Contreras ◽  
Armando Baeza-Barrera ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Nanoparticle Synthesis ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pure Phase ◽  
High Level ◽  
Shape Tuning ◽  
Magnetite Phase

In this work, we present a simple and efficient method for pure phase magnetite (Fe3O4) nanoparticle synthesis. The phase structure, particle shape, and size of the samples were characterized by Raman spectroscopy (Rm), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDS), and transmission electron microscopy (TEM). The morphology tuning was controlled by the temperature of the reaction; the nanoparticles were synthesized via the hydrothermal method at 120°C, 140°C, and 160°C, respectively. The Rm and XRD spectra showed that all the nanoparticles were Fe3O4 in a pure magnetite phase. The obtained nanoparticles exhibited a high level of crystallinity with uniform morphology at each temperature, as can be observed through TEM and SEM. These magnetic nanoparticles exhibited good saturation magnetization and the resulting shapes were quasi-spheres, octahedrons, and cubes. The samples showed striking magnetic properties, which were examined by a vibrating sample magnetometer (VSM). It has been possible to obtain a good morphological control of nanostructured magnetite in a simple, economical, and scalable method by adjusting the temperature, without the modification of any other synthesis parameter.

Hydrothermal Synthesis and Photocatalytic Properties of TiO2/SnS2 Nanocomposite

2014 ◽  
Vol 898 ◽  
pp. 23-26
Author(s):  
Jing Li ◽  
Wei Sun ◽  
Wei Min Dai ◽  
Yong Cai Zhang
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance ◽  
Photocatalytic Property ◽  
Deionized Water ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Chloride Pentahydrate

TiO2/SnS2 nanocomposite was synthesized via hydrothermal treatment of tin (IV) chloride pentahydrate, thioacetamide and TiO2 nanotubes in deionized water at 150 °C for 3 h. The structure, composition and optical property of the as-synthesized nanocomposite were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and UV-vis diffuse reflectance spectra, and its photocatalytic property was tested in the reduction of aqueous Cr6+ under visible-light (λ > 420 nm) irradiation. It was observed that TiO2 nanotubes exhibited no photocatalytic activity, whereas TiO2/SnS2 nanocomposite exhibited photocatalytic activity in the reduction of aqueous Cr6+ under visible-light (λ > 420 nm) irradiation.

Low-Temperature Molten Salt Synthesis of NiWO4 Nanoparticles

2011 ◽  
Vol 311-313 ◽  
pp. 545-548 ◽  
Author(s):  
Yu Jiang Wang ◽  
Yong Gang Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Molten Salt ◽  
Molten Salt Synthesis ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pure Phase

NiWO4 nanoparticles were successfully synthesized by a molten salt method at 270°C. The as-prepared powders were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and exhibited a pure phase NiWO4 with about 50 nm in particle size and uniform nearly-spherical particle shape.

scholarly journals Synthesis of porous LaFeO3 prepared by nanocasting method for photo-Fenton degradation of oily-containing wastewater

2021 ◽  
Vol 11 (1) ◽  
pp. xx-xx
Author(s):  
Nga Phan To ◽  
Lien Nguyen Hong ◽  
Tuyen Le Van ◽  
Nhan Phan Chi ◽  
Huyen Phan Thanh
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Transmission Electron ◽  
Visible Light Driven ◽  
Adsorption Desorption

Porous LaFeO3 were synthesised by nanocasting method using mesoporous silica (SBA-15) as a hard template and used as a visible-light-driven photocatalyst. The as-synthesised LaFeO3 photocatalyst were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray Diffraction (XRD), N2 adsorption-desorption, and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-vis DRS). The photo-Fenton catalytic activities of porous LaFeO3 were investigated for the degradation of oily-containing wastewater. The results showed that porous LaFeO3 had better photo-Fenton catalytic activity under visilbe light irradiation than pure LaFeO3. The remarkable improvement photo-Fenton catalytic activity of porous LaFeO3 material could be attributed to the synergistic effect of adsorption and visible light photo-Fenton processes thanks to its porous structure.

scholarly journals Preparation of g-C3N4/MoS2 Composite Material and Its Visible Light Catalytic Performance

2021 ◽  
Author(s):  
Yu Fan ◽  
Yan-ning Yang ◽  
Chen Ding
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Photogenerated Electron ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Calcination Method

Abstract The g-C3N4 nanosheet was prepared by calcination method, the MoS2 nanosheet was prepared by hydrothermal method. The g-C3N4/MoS2 composites were prepared by ultrasonic composite in anhydrous ethanol. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-Vis), and photoluminescence (PL) techniques were used to characterize the materials. The photocatalytic degradation of Rhodamine B (Rh B) by g-C3N4/MoS2 composites with different mass ratios was investigated under visible light. The results show that a small amount of MoS2 combined with g-C3N4 can significantly improve photocatalytic activity. The g-C3N4/MoS2 composite with a mass ratio of 1:8 has the highest photocatalytic activity, and the degradation rate of Rh B increases from 50% to 99.6%. The main reason is that MoS2 and g-C3N4 have a matching band structure. The separation rate of photogenerated electron-hole pairs is enhanced. So the g-C3N4/MoS2 composite can improve the photocatalytic activity. The photocatalytic mechanism was proposed through the active matter capture experiment.

scholarly journals Facile Solvothermal Synthesis of CuCo2S4 Yolk-Shells and Their Visible-Light-Driven Photocatalytic Properties

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2303 ◽  
Author(s):  
Yinxia Chen ◽  
Xianbing Ji ◽  
Vadivel Sethumathavan ◽  
Bappi Paul
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photocatalytic Property ◽  
Shell Shape ◽  
X Ray Diffraction ◽  
Exchange Method ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Light Driven ◽  
Photocatalytic Applications

In this present work, we synthesized a yolk-shell shaped CuCo2S4 by a simple anion exchange method. The morphological and structural properties of the as-synthesized sample were characterized using X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (UV-vis DRS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The SEM and TEM results confirmed that the uniform yolk-shell structure was formed during the solvothermal process. The band gap was about 1.41 eV, which have been confirmed by UV–vis DRS analysis. The photocatalytic property was evaluated by the photocatalytic degradation of methylene blue (MB) dye as a target pollutant under the visible-light irradiation. The experimental results confirmed the potential application of yolk-shell shape CuCo2S4 in visible-light photocatalytic applications.

Preparation and visible-light photocatalyst activity of nanometric-sized TiO2-xNy powders from a two-microemulsion process

2009 ◽  
Vol 24 (8) ◽  
pp. 2574-2583 ◽  
Author(s):  
Wein-Duo Yang ◽  
Wen-Chung Lin ◽  
Chunhui Yang ◽  
Zen-Ja Chung ◽  
I-Lun Huang
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Ph Value ◽  
Methylene Blue Solution ◽  
Visible Light Photocatalyst ◽  
X Ray ◽  
Nitrogen Doped ◽  
Transmission Electron ◽  
Pure Phase ◽  
Blue Solution

Nanometric-sized nitrogen-doped titanium oxide (TiO2-xNy) powders were synthesized by the two-microemulsion technology. The dried precursor precipitate was characterized by differential thermal analysis/thermogravimetric analysis, Raman spectroscopy, transmission electron microscopy, Brunauer-Emmet-Teller, and x-ray photoelectron spectrometer (XPS), and the mechanisms for the evolution of TiO2-xNy powders in this process were proposed and discussed in the context of the microstructure. It shows that a higher pH value solution results in obtaining a small size and much more homogeneous TiO2-xNy powder after calcinations. The powder prepared from a solution of pH 10–11 and calcined at 500 °C has a particle size of ∼4–6 nm with a specific surface area of 160 m2/g and exhibits a pure phase of anatase containing ∼5 mol% of N evidenced by XPS. However, the nanometric-sized TiO2-xNy powder shows the photocatalytic degradation of methylene blue solution effectively by exposing the powders in aqueous solution under visible light.

Sign in / Sign up

Export Citation Format

Share Document