Size-Dependent Effect of Cu2O Nanocubes in Electrochemical and Photocatalytic Properties

2018 ◽  
Vol 18 (12) ◽  
pp. 8282-8288 ◽  
Author(s):  
Yuanyuan Tang ◽  
Yinlong Xu ◽  
Caiyu Qi ◽  
Xianyang Li ◽  
Enming Xing ◽  
...  

Cu2O nanocubes with different size (ranging from 20 nm to 400 nm) were prepared by a seed-mediated method to systematically explore the strong size-dependent properties in photocatalytic degradation of methyl orange (MO). Cu2O nanotubes were characterized by TEM, XRD, UV-Vis measurements. The size-dependent photocatalytic efficiency of the Cu2O nanocubes was evaluated by degradation of methyl orange (MO) in water under visible light (λ > 420 nm) irradiation. Furthermore, the photocurrent, linear sweep voltammetry (LSV) and electrochemical impedance spectra (EIS) measurements were applied to elucidate the size-dependent properties of Cu2O nanocubes, which demonstrated that smaller Cu2O nanocubes with certain length (30 nm) showed higher current density, faster electron transfer and lower rate of charge recombination in their exposed (100) facet. Therefore, 30 nm Cu2O nanocubes showed stronger visible light absorption capacity and higher photocatalytic activity in MO degradation among a series of nanocubes (20, 30, 100, 130, 200 and 400 nm) and their corresponding photocatalytic activities decreased with increasing the particles sizes.

Author(s):  
Atef Y. Shenouda ◽  
M. M. S. Sanad

Li2NixFe1−xSiO4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) samples were prepared by sol–gel process. The crystal structure of prepared samples of Li2NixFe1−xSiO4 was characterized by XRD. The different crystallographic parameters such as crystallite size and lattice cell parameters have been calculated. Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) investigations were carried out explaining the morphology and function groups of the synthesized samples. Furthermore, electrochemical impedance spectra (EIS) measurements are applied. The obtained results indicated that the highest conductivity is achieved for Li2Ni0.4Fe0.6SiO4 electrode compound. It was observed that Li/Li2Ni0.4Fe0.6SiO4 battery has initial discharge capacity of 164 mAh g−1 at 0.1 C rate. The cycle life performance of all Li2NixFe1−xSiO4 batteries was ranged between 100 and 156 mAh g−1 with coulombic efficiency range between 70.9% and 93.9%.


NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  

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.


2016 ◽  
Vol 703 ◽  
pp. 321-325
Author(s):  
Hai Feng Chen ◽  
Jia Mei Chen ◽  
Zhi Xue Pan

In this work, novel Cu/BiVO4 photocatalyst were prepared by a low-temperature solid state grinding method using Bi (NO3)3•5H2O, NH4VO3 and Cu (NO3)2•2H2O as raw materials. The structure and properties of the samples were characterized by Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) and UV-vis diffused reflectance spectroscopy (DRS); Using the degradation of methyl orange (MO) as the probe, it was simulated as the degradation of sewage under the visible light to study the influence of the illumination time and the amount of photocatalysts. Compared with the pure BiVO4, the visible-light absorption scope of BiVO4 was broadened by doping Cu, the UV-Visible absorption edges were slightly red shift and the band gap was narrower. Comparatively speaking, the results indicted that the doped Cu enhanced the photocatalytic activities of BiVO4.


2015 ◽  
Vol 39 (8) ◽  
pp. 6171-6177 ◽  
Author(s):  
Mingshan Fan ◽  
Bo Hu ◽  
Xu Yan ◽  
Chengjie Song ◽  
Tianjun Chen ◽  
...  

Heterostructure complexes of Cu2O/NaNbO3exhibited high catalytic activities on the degradation of methyl orange.


2016 ◽  
Vol 27 (26) ◽  
pp. 265703 ◽  
Author(s):  
Wei Zhang ◽  
Xiaolin Li ◽  
Zhi Yang ◽  
Xuehui Tang ◽  
Yujie Ma ◽  
...  

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