scholarly journals Electrospun ZnO/Bi2O3Nanofibers with Enhanced Photocatalytic Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yingying Yang ◽  
Lingling Xu ◽  
Chunyan Su ◽  
Jixin Che ◽  
Wenjun Sun ◽  
...  

ZnO/Bi2O3nanofibers were synthesized by a simple electrospinning method and both the UV and visible light responsive photocatalytic properties were studied by the decolorization of RhB dye. Thermogravimetric analysis/differential thermal analysis (TGA-DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), and UV-vis diffuse reflectance spectra (DRS) were employed to study the structure, morphology, and optical properties of the ZnO/Bi2O3nanofibers, respectively. The relationship between the ZnO/Bi2O3ratio and photocatalytic activity was also studied, and the composite with a molar ratio of 23 : 1 demonstrated the best activity under both excitations. The photocatalytic mechanisms for the composite fibers can be described as the direct photocatalysis under UV excitation and photosensitation for visible light irradiation. The enhanced photocatalytic activities can be ascribed to the effective electron-hole pairs separation that leads to the promoted photocatalytic efficiency.

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.


2018 ◽  
Vol 32 (17) ◽  
pp. 1850185 ◽  
Author(s):  
Yun-Hui Si ◽  
Yu Xia ◽  
Ya-Yun Li ◽  
Shao-Ke Shang ◽  
Xin-Bo Xiong ◽  
...  

A series of BiFeO3 and BiFe[Formula: see text]Mn[Formula: see text]O3 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by a hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy (EDS) and UV–Vis diffuse reflectance spectroscopy, and their photocatalytic activity was studied by photocatalytic degradation of methylene blue in aqueous solution under visible light irradiation. The band gap of BiFeO3 was significantly decreased from 2.26 eV to 1.90 eV with the doping of Mn. Furthermore, the 6% Mn-doped BiFeO3 photocatalyst exhibited the best activity with a degradation rate of 94% after irradiation for 100 min. The enhanced photocatalytic activity with Mn doping could be attributed to the enhanced optical absorption, increment of surface reactive sites and reduction of electron–hole recombination. Our results may be conducive to design more efficient photocatalysts responsive to visible light among narrow band gap semiconductors.


NANO ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. 1850129 ◽  
Author(s):  
Chujun Chen ◽  
Xia Xin ◽  
Jinniu Zhang ◽  
Gang Li ◽  
Yafeng Zhang ◽  
...  

To improve the high charge carrier recombination rate and low visible light absorption of {001} facets exposed TiO2 [TiO2(001)] nanosheets, few-layered MoS2 nanoparticles were loaded on the surfaces of TiO2(001) nanosheets by a simple photodeposition method. The photocatalytic activities towards Rhodamine B (RhB) were investigated. The results showed that the MoS2–TiO2(001) nanocomposites exhibited much enhanced photocatalytic activities compared with the pure TiO2(001) nanosheets. At an optimal Mo/Ti molar ratio of 25%, the MoS2–TiO2(001) nanocomposites displayed the highest photocatalytic activity, which took only 30[Formula: see text]min to degrade 50[Formula: see text]mL of RhB (50[Formula: see text]mg/L). The active species in the degradation reaction were determined to be h[Formula: see text] and [Formula: see text]OH according to the free radical trapping experiments. The reduced charge carrier recombination rate, enhanced visible light utilization and increased surface areas contributed to the enhanced photocatalytic performances of the 25% MoS2–TiO2(001) nanocomposites.


2014 ◽  
Vol 787 ◽  
pp. 35-40 ◽  
Author(s):  
Xiao Yan Zhou ◽  
Peng Wei Zhou ◽  
Hao Guo ◽  
Bo Yang ◽  
Ru Fei Ren

The p-n junction photocatalysts, p-CuO (at. 0-25%)/n-ZnO nanocomposite were prepared through hydrothermal method without using any organic solvent or surfactant. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-Ray spectroscopy, and UV-vis spectroscopy. The results demonstrated that the CuO/ZnO nanocomposite presented a two-dimensional morphology composed of sheet-like ZnO nanostructures adorned with CuO nanoparticles. The photocatalytic activity of CuO/ZnO with different Cu/Zn molar rations and pure ZnO synthesized by the identical synthetic route were evaluated by degrading methylene blue (MB) dye under UV-visible light irradiation. The CuO/ZnO with Cu/Zn molar ratio of 4% exhibits the highest photocatalytic activity compared that of the other photocatalysts under the identical conditions. It is mainly attributed to the increased charge separation rate in the nanocomposite and the extended photo-responding range.


2019 ◽  
Vol 43 (11) ◽  
pp. 4455-4462 ◽  
Author(s):  
Mohammed Ismael ◽  
Ying Wu ◽  
Michael Wark

The synthesized ZrO2/g-C3N4 composites exhibit superior performance in water splitting for hydrogen production due to the effective electron–hole separation at the composite interface.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Mathana Wongaree ◽  
Siriluk Chiarakorn ◽  
Surawut Chuangchote

Photocatalytic activity ofTiO2nanoparticles was successfully enhanced by addition of multiwall carbon nanotubes (MWCNT) to make CNT/TiO2nanocomposites by sol-gel method at ambient temperature. CNT treated by HNO3 : H2SO4treatment (1 : 3 v/v) was mixed withTiO2nanoparticles at various molar ratios and calcination temperatures. The optimal molar ratio of CNT : TiO2was found at 0.05 : 1 by weight. The optimal calcination condition was 400°C for 3 h. From the results, the photocatalytic activities of CNT/TiO2nanocomposites were determined by the decolorization of 1 × 10−5 M methylene blue (MB) under visible light. CNT/TiO2nanocomposites could enhance the photocatalytic activity and showed faster for the degradation of MB with only 90 min. The degradation efficiency of the MB solution with CNT/TiO2nanocomposite achieved 70% which was higher than that with pristineTiO2(22%). This could be explained that CNT preventsTiO2from its agglomeration which could further enhance electron transfer in the composites. In addition, CNT/TiO2nanocomposites had high specific surface area (202 m2/g) which is very promising for utilization as a photocatalyst for environmental applications.


NANO ◽  
2017 ◽  
Vol 12 (06) ◽  
pp. 1750072 ◽  
Author(s):  
Tao Wang ◽  
Changchang Ma ◽  
Dan Wu ◽  
Xinlin Liu ◽  
Yang Liu ◽  
...  

In this paper, a novel heterostructure of 0D/3D-CdSe/Bi[Formula: see text]TiO[Formula: see text] pyramidal photocatalyst was synthesized and characterized. It exhibited significantly photocatalytic efficiency in photocatalytic degradation of the tetracycline than pure Bi[Formula: see text]TiO2 and CdSe and showed high stability. The enhanced photocatalytic activity might be attributed to the formation of heterostructure between CdSe QDs and 3D Bi[Formula: see text]TiO[Formula: see text], in which CdSe QDs served as electron trapper to improve the separation of photodegradation electron–hole pairs, and provided a number of active adsorption sites for the photogenerated of pollutants. The photocatalytic mechanism of 0D/3D-CdSe/Bi[Formula: see text]TiO[Formula: see text] pyramidal heterostructure was also proposed.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Honghui Teng ◽  
Shukun Xu ◽  
Dandan Sun ◽  
Ying Zhang

Fe-doped TiO2nanotubes (Fe-TNTs) have been prepared by ultrasonic-assisted hydrothermal method. The structure and composition of the as-prepared TiO2nanotubes were characterized by transmission electron microscopy, X-ray diffraction, and UV-Visible absorption spectroscopy. Their photocatalytic activities were evaluated by the degradation of MO under visible light. The UV-visible absorption spectra of the Fe-TNT showed a red shift and an enhancement of the absorption in the visible region compared to the pure TNT. The Fe-TNTs were provided with good photocatalytic activities and photostability and under visible light irradiation, and the optimum molar ratio of Ti : Fe was found to be 100 : 1 in our experiments.


2016 ◽  
Vol 852 ◽  
pp. 1473-1476
Author(s):  
Yan Ding ◽  
Liang Fang Fu ◽  
Yu Huan Wang ◽  
Liang Chao Li ◽  
Juan Bi Li

A series of photocatalyst Bi1-xLaxVO4 (0.1, 0.3, 0.5, 0.7) powders were prepared by hydrothermal method. The composition, structure, morphology and photocatalytic activity of the samples were researched by means of modern testing techniques. Bi1-xLaxVO4 showed excellent visible-light sensitivity and photocatalytic activities. The degradation rate of sample with x = 0.5 on rhodamine B reached 90 %, which was much higher than that of pure BiVO4.


2014 ◽  
Vol 955-959 ◽  
pp. 2267-2275 ◽  
Author(s):  
Rong Liu ◽  
Shi Duo Zhao ◽  
Xue Lin

Ba0.6Mg0.4TiO3 (BMT) particles with different morphologies were synthesized through hydrothermal method and their optical and photocatalytic properties were investigated. Their crystal structure and microstructures were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). XRD patterns demonstrate that the as-prepared samples are tetragonal structure. FESEM shows that BMT crystals can be fabricated in different morphologies by simply manipulating the reaction parameters of hydrothermal process. The UV-visible diffuse reflectance spectra (UV-vis DRS) reveal that the band gaps of BMT photocatalysts are about 2.37 - 2.51 eV. The as-prepared BMT photocatalysts exhibite higher photocatalytic activities in the degradation of methyl orange (MO) under visible light irradiation (λ > 420 nm) compared with traditional N-doped TiO2 (N-TiO2) and pure BaTiO3 (BTO). The high photocatalytic performance of BMT photocatalysts could be attributed to the recombination restraint of the e-/h+ pairs resulting from doping of Mg2+ ions. The influence of morphologies upon the photocatalytic properties of BMT was studied. Furthermore, BMT nanowires reveal the highest photocatalytic activity. Up to 94.0% MO is decolorized after visible light irradiation for 360 min.


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