Microwave-assisted synthesis of Ce-doped ZnO/CNT composite with enhanced photo-catalytic activity

2017 ◽  
Vol 43 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Md. Elias ◽  
Md. Khairul Amin ◽  
Shakhawat H. Firoz ◽  
Md. Asjad Hossain ◽  
Sonia Akter ◽  
...  
2021 ◽  
Vol 317 ◽  
pp. 119-124
Author(s):  
Sabiu Said Abdullahi ◽  
Garba Shehu Musa Galadanci ◽  
Norlaily Mohd Saiden ◽  
Josephine Ying Chyi Liew

The emergence of Dilute Magnetic Semiconductors (DMS) with a potentials for spintronic application have attracted much researches attention, special consideration has been given to ZnO semiconductor material due to its wide band gap of 3.37 eV, large exciting binding energy of 60 meV, moreover, its ferromagnetic behavior at room temperature when doped with transition metals. MxZn1-xO (M = Fe or Ni) nanoparticles were synthesized by microwave assisted synthesis method calcined at 600°C. The structural, morphological and magnetic properties of these nanoparticles were studied using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Vibrating Sample Magnetometer (VSM) respectively. Single phase Wurtzite hexagonal crystal structure was observed for the undoped and Fe doped ZnO nanoparticles with no any impurity, whereas Ni doped ZnO nanoparticles shows the formation of NiO impurities. The magnetic measurement reveals a diamagnetic behavior for the undoped ZnO meanwhile a clear room temperature ferromagnetism was observed for both Fe and Ni doped ZnO. Fe doped ZnO present a high saturation magnetization compared to Ni doped ZnO. However, Ni doped ZnO present high coercivity. The research was confirmed that Fe doped ZnO material will be good material combination for spintronic applications.


2018 ◽  
Vol 2 (7) ◽  
pp. 1561-1573 ◽  
Author(s):  
Manjunath Chatti ◽  
Alexey M. Glushenkov ◽  
Thomas Gengenbach ◽  
Gregory P. Knowles ◽  
Tiago C. Mendes ◽  
...  

A rapid low-temperature microwave-assisted synthesis of nickel(iron) layered hydroxides and sulphides that exhibit robust catalytic activity for electrooxidation of alkaline water is introduced.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tsz-Lung Kwong ◽  
Ka-Fu Yung

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.


2011 ◽  
Vol 184 (2) ◽  
pp. 391-400 ◽  
Author(s):  
Mukta V. Limaye ◽  
Shashi B. Singh ◽  
Raja Das ◽  
Pankaj Poddar ◽  
Sulabha K. Kulkarni

2005 ◽  
Vol 09 (03) ◽  
pp. 163-169 ◽  
Author(s):  
Farzad Bahadoran ◽  
Solmaz Dialameh

Substituted iron and cobalt phthalocyanines are easily prepared by microwave irradiation of the starting materials under solvent free condition, which reduced reaction time considerably. The synthesized metallophthalocyanines (octachloro-, tetranitro-, tetracarboxy- or polyphthalocyanine) are used as epoxidation catalysts of cyclooctene in homogeneous and heterogeneous conditions by iodosylbenzene as an oxidant. Their catalytic activities have shown that the electron withdrawing groups on the phthalocyanine ring have a very small effect on stability of the catalyst during the reactions.


2021 ◽  
Vol 21 (4) ◽  
pp. 2483-2494
Author(s):  
Aqeel Ahmed Shah ◽  
Ali Dad Chandio ◽  
Asif Ahmed Sheikh

The design of sensitive and efficient photo catalyst for the energy and environmental applications with minimum charge recombination rate and excellent photo conversion efficiency is a challenging task. Herein we have developed a nonmetal doping methodology into ZnO crystal using simple solvothermal approach. The boron (B) is induced into ZnO. The doping of B did not make any significant change on the morphology of ZnO nano rods as confirmed by scanning electron microscopy (SEM) without considerable change on periodic arrangement of nanostructures. The existence of B, Zn, and O is shown by energy dispersive spectroscopy (EDS). The X-ray diffraction (XRD) patterns are well matched to the hexagonal phase for both pristine ZnO and B-doped ZnO. The XRD has shown slight dislocation of 2theta degree. The UV-visible spectroscopy was used to measure the optical bandgap and photo catalytic activity for the degradation of organic dyes. The nonmetal doped ZnO has shown potential and outstanding photo catalytic activity for the photo degradation of methylene blue (MB), methyl orange (MO) and rhodamine B in aqueous solution. The photo degradation efficiency of MB, MO and rhodamine B is found to be 96%, 86% and 80% respectively. The enhanced photo catalytic activity of B-doped ZnO is indexed to the inhibited charge recombination rate due to the reduction in the optical bandgap. Based on the obtained results, it can be said that nonmetal doping is excellent provision for the design of active materials for the extended range of applications.


2016 ◽  
Vol 32 (1-2) ◽  
pp. 49
Author(s):  
Jemal Mohammed Yasin ◽  
O. P. Yadav ◽  
Abi M. Taddesse

Nano-size Ag-N co-doped ZnO-CuO composites have been synthesized and tested for their photo-catalytic activity towards degradation of methyl orange in aqueous solution under visible as well as UV radiations. Crystal structure, surface functional groups, metallic composition and band structure of as-synthesized nano-material were investigated using XRD, FTIR, AAS and UV-Vis spectroscopic techniques, respectively. Ag-N co-doped ZnO-CuO photocatalyst showed higher photo-catalytic activity than Ag- or N-doped and undoped composite photocatalysts. The observed highest activity of Ag-N co-doped ZnO-CuO among the studied photo-catalysts, is attributed to the cumulative effects of lowering of band-gap energy and decrease of recombination rate of photo-generated electrons and holes owing to doped N and Ag, respectively. Effects of photo-catalyst load, solution pH and substrate initial concentration on the degradation of methyl orange have also been studied.


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