scholarly journals Photocatalytic and Photo-Fenton Catalytic Degradation Activities of Z-Scheme Ag2S/BiFeO3 Heterojunction Composites under Visible-Light Irradiation

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 399 ◽  
Author(s):  
Lijing Di ◽  
Hua Yang ◽  
Tao Xian ◽  
Xueqin Liu ◽  
Xiujuan Chen
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Dye Degradation ◽  
Synergistic Effects ◽  
Active Species ◽  
Light Irradiation ◽  
Precipitation Method ◽  
Photoexcited Electron ◽  
Catalytic Mechanisms ◽  
Ag2s Nanoparticles

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.

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
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Active Role ◽  
Active Species ◽  
Light Irradiation ◽  
Free Radical Scavengers ◽  
Precipitation Method ◽  
X Ray ◽  
Composite Photocatalysts

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.

Photocatalytic Degradation of Methylene Blue over Co-Ag3VO4 under Visible Light Irradiation

2011 ◽  
Vol 335-336 ◽  
pp. 1385-1390 ◽  
Author(s):  
Shuo Wiei Zhao ◽  
Hui Xu ◽  
Hua Ming Li ◽  
Yuan Guo Xu
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Absorption Edge ◽  
Diffuse Reflectance Spectroscopy ◽  
Dye Degradation ◽  
Light Irradiation ◽  
Experimental Conditions ◽  
X Ray

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.

scholarly journals Concurrent Photocatalytic Hydrogen Generation and Dye Degradation Using MIL-125-NH2 under Visible Light Irradiation

2018 ◽  
Vol 28 (52) ◽  
pp. 1806368 ◽  
Author(s):  
Stavroula Kampouri ◽  
Tu N. Nguyen ◽  
Mariana Spodaryk ◽  
Robert G. Palgrave ◽  
Andreas Züttel ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Hydrogen Generation ◽  
Dye Degradation ◽  
Light Irradiation ◽  
Photocatalytic Hydrogen Generation

scholarly journals Photocatalytic Hydrogen Production from Glycerol Aqueous Solution Using Cu-Doped ZnO under Visible Light Irradiation

2019 ◽  
Vol 9 (13) ◽  
pp. 2741 ◽  
Author(s):  
Vincenzo Vaiano ◽  
Giuseppina Iervolino
Keyword(s):  
Hydrogen Production ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Noble Metals ◽  
Light Irradiation ◽  
Precipitation Method ◽  
Glycerol Solution ◽  
Glycerol Concentration ◽  
Photocatalytic Hydrogen Production ◽  
Doped Zno

Cu-doped ZnO photocatalysts at different Cu loadings were prepared by a precipitation method. The presence of Cu in the ZnO crystal lattice led to significant enhancement in photocatalytic activity for H2 production from an aqueous glycerol solution under visible light irradiation. The best Cu loading was found to be 1.08 mol %, which allowed achieving hydrogen production equal to 2600 μmol/L with an aqueous glycerol solution at 5 wt % initial concentration, the photocatalyst dosage equal to 1.5 g/L, and at the spontaneous pH of the solution (pH = 6). The hydrogen production rate was increased to about 4770 μmol/L by increasing the initial glycerol concentration up to 10 wt %. The obtained results evidenced that the optimized Cu-doped ZnO could be considered a suitable visible-light-active photocatalyst to be used in photocatalytic hydrogen production without the presence of noble metals in sample formulation.

scholarly journals Facile Preparation of CNT/Ag2S Nanocomposites with Improved Visible and NIR Light Photocatalytic Degradation Activity and Their Catalytic Mechanism

Micromachines ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 503 ◽  
Author(s):  
Lijing Di ◽  
Tao Xian ◽  
Xiaofeng Sun ◽  
Hongqin Li ◽  
Yongjie Zhou ◽  
...  
Keyword(s):  
Catalytic Mechanism ◽  
Dye Degradation ◽  
Average Particle Size ◽  
Hybrid Nanocomposites ◽  
Light Irradiation ◽  
Precipitation Method ◽  
Average Particle ◽  
Nir Light ◽  
Photocatalytic Activities ◽  
Ag2s Nanoparticles

In this work, a series of carbon nanotubes (CNT)/Ag2S hybrid nanocomposites were successfully prepared by a facile precipitation method. Transmission electron microscope (TEM) observation indicates that Ag2S nanoparticles with an average particle size of ~25 nm are uniformly anchored on the surface of CNT. The photocatalytic activities of the CNT/Ag2S nanocomposites were investigated toward the degradation of rhodamine B (RhB) under visible and near-infrared (NIR) light irradiation. It is shown that the nanocomposites exhibit obviously enhanced visible and NIR light photocatalytic activities compared with bare Ag2S nanoparticles. Moreover, the recycling photocatalytic experiment demonstrates that the CNT/Ag2S nanocomposites possess excellent photocatalytic stability. The photoelectrochemical and photoluminescence measurements reveal the efficient separation of photogenerated charges in the CNT/Ag2S nanocomposites. This is the dominant reason behind the improvement of the photocatalytic activity. Based on active species trapping experiments, the possible photocatalytic mechanism of CNT/Ag2S nanocomposites for dye degradation under visible and NIR light irradiation was proposed.

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