Preparation of Ag3PO4/BiOCOOH Composite Photocatalysts with High Photocatalytic Performances Under Visible Light Irradiation

NANO ◽  
2016 ◽  
Vol 11 (09) ◽  
pp. 1650105 ◽  
Author(s):  
Xiaoting Meng ◽  
Xiaofang Cheng ◽  
Dongrong Zhuang ◽  
Shaogui Yang ◽  
Cheng Sun

A series of Ag3PO4/BiOCOOH composite photocatalysts have been successfully synthesized by a simple in situ ion precipitation method. The crystallinity, morphology, microstructure, composition and optical property were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive spectrum (EDS), Fourier transform infrared spectrometer (FT-IR), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectrophotometer (DRS). The as-prepared catalysts exhibited excellent photocatalytic activity for the degradation of RhB and MB under visible light irradiation, the 2:1 Ag3PO4/BiOCOOH exhibited the best photocatalytic activity. By adding different free radical scavengers, the catalytic mechanism was discussed. In the process of degradation of RhB, holes (h[Formula: see text] is the main active species, [Formula: see text]O[Formula: see text] played a certain active role, [Formula: see text]OH played a small role. In the process of degradation MB, holes (h[Formula: see text] is the main active species too, [Formula: see text]O[Formula: see text] also played a certain active role, [Formula: see text]OH almost does not work.

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1332
Author(s):  
Duc Quang Dao ◽  
Thi Kim Anh Nguyen ◽  
Thanh-Truc Pham ◽  
Eun Woo Shin

Co-doped NiTiO3/g-C3N4 composite photocatalysts were prepared by a modified Pechini method to improve their photocatalytic activity toward methylene blue photodegradation under visible light irradiation. The combination of Co-doped NiTiO3 and g-C3N4 and Co-doping into the NiTiO3 lattice synergistically enhanced the photocatalytic performance of the composite photocatalysts. X-ray photoelectron spectroscopy results for the Co-doped NiTiO3/g-C3N4 composite photocatalysts confirmed Ti-N linkages between the Co-doped NiTiO3 and g-C3N4. In addition, characteristic X-ray diffraction peaks for the NiTiO3 lattice structure clearly indicated substitution of Co into the NiTiO3 lattice structure. The composite structure and Co-doping of the C-x composite photocatalysts (x wt % Co-doped NiTiO3/g-C3N4) not only decreased the emission intensity of the photoluminescence spectra but also the semicircle radius of the Nyquist plot in electrochemical impedance spectroscopy, giving the highest kapp value (7.15 × 10−3 min−1) for the C-1 composite photocatalyst.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Zhiqing Yong ◽  
Jian Ren ◽  
Huilin Hu ◽  
Peng Li ◽  
Shuxin Ouyang ◽  
...  

Novel graphitic carbon nitride/KTaO3(g-C3N4/KTaO3) nanocomposite photocatalysts have been successfully synthesized via a facile and simple ultrasonic dispersion method. Compared to either g-C3N4or KTaO3, the composite photocatalysts show significantly increased photocatalytic activity for degradation of Rhodamine B (RhB) under visible light irradiation. The increased photocatalytic performance of the composite could be attributed to the enhanced photogenerated charge carrier separation capacity. Moreover, it is observed that∙O2-is the main active species in the photocatalytic degradation of RhB using the g-C3N4/KTaO3composite photocatalysts.


2011 ◽  
Vol 335-336 ◽  
pp. 1385-1390 ◽  
Author(s):  
Shuo Wiei Zhao ◽  
Hui Xu ◽  
Hua Ming Li ◽  
Yuan Guo Xu

In order to improve the photocatalytic activity, Co was successfully loaded into Ag3VO4 by using impregnation process. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS) and diffuse reflectance spectroscopy (DRS). The XRD and SEM–EDS analyses revealed that Co ion was dispersed on Ag3VO4. The DRS results indicated that the absorption edge of the Co–Ag3VO4 catalyst shifted to longer wavelength. The enhanced photocatalytic activity of Co–Ag3VO4 for Methylene Blue(MB) dye degradation under visible light irradiation was due to its wider absorption edge and higher separation rate of photo-generated electron and holes. In the experimental conditions, it is demonstrated that the MB was effectively degraded by more than 95% within 40 min when the Co–Ag3VO4 catalyst was calcined at 300°C with 1 wt.% Co content.


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.


2013 ◽  
Vol 726-731 ◽  
pp. 491-494
Author(s):  
En Guo Wang ◽  
Zhen Qin Zhan

InxBi1-xVO4 photocatalyst particles were prepared by low temperature solid reaction using nitrate of indium and bismuth and NH4VO4 as the starting materials, and followed by the sintering at various temperatures. The as-prepared samples were investigated by X-ray powder diffraction (XRD), and the photocatalytic activity was carried out by the concentration change of methylene blue in the solution after visible light irradiation. The experiment results show that the orthorhombic phase InVO4 is dominant in the photocatalyst samples prepared at sintering temperature higher than 600°C. In addition, the increase in indium content in the InxBi1-xVO4 particle has greatly improved the photocatalytic activity for decomposition of aqueous methylene blue under visible light irradiation.


2021 ◽  
pp. 2150334
Author(s):  
Yi-Feng Chai ◽  
Zhong-Hua Zhu ◽  
Ming-Wei Liu ◽  
Jing Zeng ◽  
Gui-Fang Huang ◽  
...  

Development photoinduced photocatalysts is a significant approach to improve photocatalytic activity and stability. Herein, we successfully prepared Zn[Formula: see text]Cd[Formula: see text]S/CeO2 composites by a facile method. It is found that the Zn[Formula: see text]Cd[Formula: see text]S/CeO2 composites show significant enhancement in photocatalytic activity for methyl orange (MO) degradation under visible and UV light irradiation. The degradation efficiency reaches up to 3.7 times higher than that of pure CeO2 under visible light irradiation. Moreover, the Zn[Formula: see text]Cd[Formula: see text]S/CeO2 samples have almost no loss of photocatalytic activity after five recycles, indicating good photocatalytic stability of the samples. The attractive photocatalytic activity of the Zn[Formula: see text]Cd[Formula: see text]S/CeO2 samples could be attributed to the robust charge carriers transfer and separation.


2009 ◽  
Vol 79-82 ◽  
pp. 2115-2118
Author(s):  
Xian Hua Zhang ◽  
Lei Ge

The novel visible-light-driven Ag/BiVO4 composite photocatalysts were successfully prepared by photo-deposition method. The as-prepared Ag/BiVO4 samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectra (DRS). The photocatalytic activities of the Ag/BiVO4 powders were determined by degradation of methyl orange molecules in water under visible light irradiation (λ>400nm). The photocatalytic experiments indicated that the composite samples enhanced photo-activity under visible light irradiation.


2011 ◽  
Vol 287-290 ◽  
pp. 1640-1645 ◽  
Author(s):  
Min Guang Fan ◽  
Zu Zeng Qin ◽  
Zi Li Liu ◽  
Tong Ming Su

A series of BixY(2-x)O3photocatalysts were successfully prepared by a solid-state reaction and were subsequently characterized by powder X-ray diffraction, UV-vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy (XPS). The UV-vis diffuse reflectance spectra revealed that the BixY(2-x)O3samples absorbed light in the visible-light range (400-800 nm). The XPS results indicated that active oxygen species were generated on the Bi1.8Y0.2O3surface, which displayed a higher photocatalytic activity. When using photocatalytic degradation molasses fermentation wastewater as a model reaction, the Bi1.8Y0.2O3showed higher photocatalytic activity in comparison to Bi0.2Y1.8O3under visible-light irradiation.


Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 399 ◽  
Author(s):  
Lijing Di ◽  
Hua Yang ◽  
Tao Xian ◽  
Xueqin Liu ◽  
Xiujuan Chen

Z-scheme Ag2S/BiFeO3 heterojunction composites were successfully prepared through a precipitation method. The morphology and microstructure characterization demonstrate that Ag2S nanoparticles (30–50 nm) are well-decorated on the surfaces of polyhedral BiFeO3 particles (500–800 nm) to form Ag2S/BiFeO3 heterojunctions. The photocatalytic and photo-Fenton catalytic activities of the as-derived Ag2S/BiFeO3 heterojunction composites were evaluated by the degradation of methyl orange (MO) under visible-light irradiation. The photocatalytic result indicates that the Ag2S/BiFeO3 composites exhibit much improved photocatalytic activities when compared with bare Ag2S and BiFeO3. The optimum composite sample was observed to be 15% Ag2S/BiFeO3 with an Ag2S mass fraction of 15%. Furthermore, the addition of H2O2 can further enhance the dye degradation efficiency, which is due to the synergistic effects of photo- and Fenton catalysis. The results of photoelectrochemical and photoluminescence measurements suggest a greater separation of the photoexcited electron/hole pairs in the Ag2S/BiFeO3 composites. According to the active species trapping experiments, the photocatalytic and photo-Fenton catalytic mechanisms of the Ag2S/BiFeO3 composites were proposed and discussed.


2017 ◽  
Vol 41 (8) ◽  
pp. 475-483 ◽  
Author(s):  
C. Chen ◽  
X. F. Lei ◽  
M. Z. Xue

Pure anatase TiO2 photocatalysts with different Ag contents were prepared via a simple sol-gel method. The as-prepared anatase Ag-doped TiO2 photocatalysts were characterised by X-ray diffraction, transmission electron microscopy, UV-Vis diffuse reflectance spectra, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, thermal gravity and differential thermal analysis, scanning electron microscopy and N2 adsorption–desorption measurements (BET). Compared with pure TiO2, Ag-doped anatase TiO2 photocatalysts exhibited not only increases in light absorption in the visible region, the separation efficiency of electron–hole pairs and surface area, but also inhibition of the titania phase transition from anatase to rutile. Photoreduction results showed that Ag-doped anatase TiO2 photocatalysts have greatly improved photocatalytic activity, compared with pure TiO2, and the reduction of Cr(VI) under visible light irradiation was much higher than that of pure TiO2. The optimum Ag content was 1.0 mol%, which led to the complete reduction of Cr(VI) under visible light irradiation (λ > 420 nm) for 4 h. The enhanced photocatalytic activity was attributed to the synergic effect of the pure anatase structure, and the increased light absorption in the visible region, separation efficiency of electron–hole pairs and atomic ratio of Ag0:Ag2O.


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