scholarly journals Surfactant-Free Microwave-Assisted Synthesis of Fe-Doped ZnO Nanostars as Photocatalyst for Degradation of Tropaeolin O in Water under Visible Light

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tsz-Lung Kwong ◽  
Ka-Fu Yung
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Irradiation Time ◽  
Catalyst Loading ◽  
Orthogonal Experimental Design ◽  
Microwave Assisted Synthesis ◽  
X Ray ◽  
Microwave Assisted ◽  
Vis Spectroscopy ◽  
Doped Zno

Iron-doped zinc oxide nanostar was synthesized by the microwave-assisted surfactant-free hydrolysis method. The as-synthesized Fe-doped ZnO nanostars catalyst was fully characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (XRD), and diffuse reflectance UV-vis spectroscopy (UV-DRA). The photocatalytic activity of the photocatalyst was investigated for the photocatalytic degradation of Tropaeolin O under visible light irradiation. It is observed that the doping of Fe ions enhances the absorption of the visible light and thus the photocatalytic degradation rate of Tropaeolin O would increase. Despite the Taguchi orthogonal experimental design method, the photocatalytic conversion could be achieved at 99.8% in the Fe-doped ZnO catalyzed photodegradation reaction under the optimal reaction conditions of catalyst loading (30 mg), temperature (60°C), light distance (0 cm), initial pH (pH = 9), and irradiation time (3 h). The Fe-doped ZnO photocatalyst can also be easily recovered and directly reused for eight cycles with over 70% conversion.

scholarly journals Microwave Assisted Synthesis of ZnO Nanoparticles: Effect of Precursor Reagents, Temperature, Irradiation Time, and Additives on Nano-ZnO Morphology Development

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Gastón P. Barreto ◽  
Graciela Morales ◽  
Ma. Luisa López Quintanilla
Keyword(s):  
Irradiation Time ◽  
Radiation Power ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
Nano Zno ◽  
X Ray ◽  
Microwave Assisted ◽  
Vis Spectroscopy ◽  
Temperature Irradiation

The effect of different variables (precursor reagents, temperature, irradiation time, microwave radiation power, and additives addition) on the final morphology of nano-ZnO obtained through the microwave assisted technique has been investigated. The characterization of the samples has been carried out by field emission scanning electron microscopy (FE-SEM) in transmission mode, infrared (FTIR), UV-Vis spectroscopy, and powder X-ray diffraction (XRD). The results showed that all the above-mentioned variables influenced to some extent the shape and/or size of the synthetized nanoparticles. In particular, the addition of an anionic surfactant (sodium di-2-ethylhexyl-sulfosuccinate (AOT)) to the reaction mixture allowed the synthesis of smaller hexagonal prismatic particles (100 nm), which show a significant increase in UV absorption.

scholarly journals Microwave-Assisted Synthesis of Porous ZnO/SnS2Heterojunction and Its Enhanced Photoactivity for Water Purification

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
A. B. Makama ◽  
A. Salmiaton ◽  
E. B. Saion ◽  
T. S. Y. Choong ◽  
N. Abdullah
Keyword(s):  
Visible Light ◽  
Synergetic Effect ◽  
Visible Region ◽  
Microwave Assisted Synthesis ◽  
Fixed Amount ◽  
X Ray ◽  
Enhanced Absorption ◽  
Microwave Assisted ◽  
Degradation Rates ◽  
Photocatalytic Activities

Porous ZnO/SnS2nanocomposites with adjustable SnS2contents were prepared via microwave-assisted heating of different aqueous solutions of SnS2precursors in the presence of fixed amount of ZnCO3nanoparticles at pH 7. The structures, compositions, BET specific surface areas, and optical properties of the as-prepared products were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, N2adsorption, and UV-Vis absorption spectra. Photocatalytic activities of the samples were tested by the removal of aqueous ciprofloxacin,CrVI, and methylene blue under visible-light (λ>420 nm) irradiation. The experimental results reveal that the as-prepared heterogeneous nanostructures exhibit much higher visible-light-driven photocatalytic activity for the degradation of the pollutants than pure SnS2nanocrystals. The photocatalytic degradation ratesCt/C0of the pollutants for the most active heterogeneous nanostructure are about 10, 49, and 9 times higher than that of pure SnS2. The enhanced photocatalytic activities exhibited by the heterojunctions could be ascribed to the synergetic effect of enhanced absorption in the visible region and the reduced rate of charge carrier recombination because of efficient separation and electron transfer from the SnS2to ZnO nanoparticles.

scholarly journals Achieving the enhanced photocatalytic degradation of ceftriaxone sodium using CdS-g-C3N4 nanocomposite under visible light irradiation: RSM modeling and optimization

2021 ◽  
Author(s):  
Naime AttariKhasraghi ◽  
Karim Zare ◽  
Ali Mehrizad ◽  
Nasser Modirshahla ◽  
Mohammad Ali Behnajady
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Irradiation ◽  
Irradiation Time ◽  
Energy Levels ◽  
Light Irradiation ◽  
X Ray ◽  
Ceftriaxone Sodium ◽  
Operational Variables

Abstract In this research, the cadmium sulfide - graphite carbon nitride (CdS-g-C3N4) nanocomposite was synthesized and characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectrometer (EDX), and transmission electron microscopy (TEM) techniques. The photocatalytic activity of as-prepared nanocomposite was evaluated in the degradation of ceftriaxone sodium (CTX) antibiotic from aqueous solution under visible light irradiation. The influence of the operational variables such as the amount of photocatalyst (g/L), initial CTX concentration (mg/L), pH, and irradiation time (min) on the photodegradation process was investigated and optimized using response surface methodology (RSM) - central composite design (CCD) model. The maximum degradation percentage (92.55 %) was obtained in the optimal condition, including 0.06 g/L of CdS-g-C3N4 photocatalyst, 15 mg/L of CTX, pH= 10.5, and irradiation time = 81 min. The efficient photocatalytic performance of CdS-g-C3N4 nanocomposite is due to the appropriate alignment of energy levels between the CdS and g-C3N4, which synergistically impact the charge separation and the degradation efficiency of CTX. The kinetics of the photocatalytic degradation process was well described by Langmuir-Hinshelwood’s pseudo-first-order model (kapp = 0.0336 min-1).

Application of cadmium-doped ZnO for the solar photocatalytic degradation of phenol

2019 ◽  
Vol 79 (2) ◽  
pp. 375-385 ◽  
Author(s):  
Behzad Shahmoradi ◽  
Farzaneh Farahani ◽  
Shadi Kohzadi ◽  
Afshin Maleki ◽  
Mohammadamin Pordel ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Irradiation Time ◽  
Zno Nanorods ◽  
Bandgap Energy ◽  
Phenol Removal ◽  
Operational Parameters ◽  
Sem Images ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir

Abstract In this study, photocatalysis of phenol was studied using Cd-ZnO nanorods, which were synthesized by a hydrothermal method. The Cd-ZnO photocatalyst was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, and Fourier transform infrared (FT-IR) and UV-Vis spectroscopy. XRD patterns exhibit diffraction peaks indexed to the hexagonal wurtzite structures with the P63mc space group. SEM images showed that the average size of the Cd-ZnO nanorods was about 90 nm. Moreover, the nanorods were not agglomerated and were well-dispersed in the aqueous medium. FT-IR analysis confirmed that a surface modifier (n-butylamine) did not add any functional groups onto the Cd-ZnO nanorods. The dopant used in this study showed reduction of the bandgap energy between valence and conduction of the photocatalyst. In addition, effect of various operational parameters including type of photocatalyst, pH, initial concentration of phenol, amount of photocatalyst, and irradiation time on the photocatalytic degradation of phenol has been investigated. The highest phenol removal was achieved using 1% Cd-ZnO for 20 mg/l phenol at pH 7, 3 g/l photocatalyst, 120 min contact time, and 0.01 mole H2O2.

Microwave-assisted synthesis of monoclinic–tetragonal BiVO4 heterojunctions with enhanced visible-light-driven photocatalytic degradation of tetracycline

RSC Advances ◽  
2015 ◽  
Vol 5 (110) ◽  
pp. 90255-90264 ◽  
Author(s):  
Ming Yan ◽  
Yan Yan ◽  
Yilin Wu ◽  
Weidong Shi ◽  
Yinqun Hua
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Microwave Assisted Synthesis ◽  
Crystalline Phases ◽  
Microwave Assisted ◽  
M Phase ◽  
Visible Light Driven ◽  
T Phase ◽  
Microwave Assisted Method

In this study, BiVO4 photocatalysts of different crystalline phases (monoclinic scheelite (M-phase), tetragonal zircon (T-phase) and monoclinic–tetragonal heterojunction (M–T)) have been successfully synthesized via a facile microwave-assisted method.

scholarly journals Mesoporous cerium oxide nanospheres for the visible-light driven photocatalytic degradation of dyes

2014 ◽  
Vol 5 ◽  
pp. 517-523 ◽  
Author(s):  
Subas K Muduli ◽  
Songling Wang ◽  
Shi Chen ◽  
Chin Fan Ng ◽  
Cheng Hon Alfred Huan ◽  
...  
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Cerium Oxide ◽  
Organic Dyes ◽  
Mixed Valence ◽  
Active Species ◽  
Oxide Material ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Earth Abundant

A facile, solvothermal synthesis of mesoporous cerium oxide nanospheres is reported for the purpose of the photocatalytic degradation of organic dyes and future applications in sustainable energy research. The earth-abundant, relatively affordable, mixed valence cerium oxide sample, which consists of predominantly Ce7O12, has been characterized by powder X-ray diffraction, X-ray photoelectron and UV–vis spectroscopy, and transmission electron microscopy. Together with N2 sorption experiments, the data confirms that the new cerium oxide material is mesoporous and absorbs visible light. The photocatalytic degradation of rhodamin B is investigated with a series of radical scavengers, suggesting that the mechanism of photocatalytic activity under visible-light irradiation involves predominantly hydroxyl radicals as the active species.

scholarly journals Solution combustion method to synthesize magnetic Fe3O4 as photocatalytic of Congo red dye and antibacterial activity

2021 ◽  
Vol 926 (1) ◽  
pp. 012050
Author(s):  
Salni ◽  
M Said ◽  
P L Hariani ◽  
I Apriani
Keyword(s):  
Photocatalytic Degradation ◽  
Congo Red ◽  
Irradiation Time ◽  
Combustion Method ◽  
Solution Combustion ◽  
X Ray ◽  
Gram Positive Bacteria ◽  
Congo Red Dye ◽  
Vis Spectroscopy ◽  
Red Dye

Abstract Fe3O4 has been synthesized using the combustion solution method using glycine as fuel. The Fe3O4 was used as a catalyst in the photocatalytic degradation of Congo red dye. The Fe3O4 were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS), UV-Vis spectroscopy, and vibrating sample magnetometry (VSM). The characterization showed that Fe3O4 has an inverse spinel structure with a crystalline size of 35.6 nm. Fe3O4 has an optical band gap of 2.16 eV, and a saturation magnetization of 83.76 emu/g. The study showed that the highest photocatalytic degradation was at 90 min of irradiation time using visible light irradiation, the concentration of Congo red dye of 10 mg/L, and pH solution of 5, with a photocatalytic degradation efficiency of 97.70%. The experiment indicated that the photocatalytic degradation of the Congo red dye by Fe3O4 followed a pseudo-first-order. Fe3O4 is effective as an antibacterial against gram-positive bacteria (Streptococcus aureus) and gram-negative bacteria (Escherichia coli).

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