Efficient Degradation of Atrazine by Magnetic CoFe2O4/g-C3N4 Catalyzed Peroxymonosulfate and Its Enhancement of Photocatalytic Ability Under Visible-Light

2019 ◽  
Vol 11 (12) ◽  
pp. 1764-1772 ◽  
Author(s):  
Ji-Bin An ◽  
Dai-Peng Hu ◽  
Yan-Lin Li ◽  
Na-Li Chen
Keyword(s):  
Visible Light ◽  
Environmental Remediation ◽  
Catalytic Performance ◽  
Catalyst Loading ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Photocatalytic Ability ◽  
Water Matrix ◽  
Visible Light Driven ◽  
Calcination Method

The Magnetic photocatalytic cobalt ferrite/graphitic-carbon nitride (CoFe2O4/g-C3N4) composites with enhanced photocatalytic activity were successfully fabricated through a simple calcination method. Scanning electron microscopy, powder X-ray diffraction, and infrared spectroscopy were applied to characterize the samples. The photocatalytic behavior of CoFe2O4/g-C3N4 was assessed by degradation of atrazine in photo Fenton-like system under visible light irradiation. The results showed that CoFe2O4/g-C3N4 with 2.0 gL–1 catalyst loading in the presence of 1 mM peroxymonosulfate (PMS) exhibited the best catalytic performance, and more than 97% of atrazine was destructed in 12 min. This enhancement could be attributed to the synergistic effect between CoFe2O4 and g-C3N4 promoting longer lifetime of separated electron–hole pairs derived from the formation of the heterojunction between CoFe2O4 and g-C3N4. This could enhance the composite-mediated activation of PMS for the visible-light driven degradation of atrazine. Moreover, the quenching tests showed that sulfate radicals were responsible for the atrazine degradation. CoFe2O4/g-C3N4 composites have strong magnetic ability, thus their recovery from water could be readily achieved by applying external magnetic field. This study demonstrates reasonable performance of the PMS/CoFe2O4/g-C3N4 system in water matrix as potentially important candidate for environmental remediation.

One-Step Hydrothermal Synthesis of Bi2S3-TiO2-RGO Composites with Enhanced Visible Light Photocatalytic Activities

NANO ◽  
2018 ◽  
Vol 13 (05) ◽  
pp. 1850051 ◽  
Author(s):  
Yanan Li ◽  
Zhongmin Liu ◽  
Yaru Li ◽  
Yongchuan Wu ◽  
Jitao Chen ◽  
...  
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Photogenerated Electron ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Photocatalytic Ability ◽  
Transmission Electron ◽  
Light Region ◽  
Infrared Spectrometer ◽  
One Step

The Bi2S3-TiO2-RGO composites were synthesized by a facile one-step hydrothermal method and applied for the photocatalytic degradation of Rhodamine B (Rh B) under the visible light. The Bi2S3-TiO2-RGO composites were characterized by transmission electron microscopy, X-ray diffraction, Raman and Fourier transform infrared spectrometer. The results indicated that the Bi2S3-TiO2-RGO composites were successfully prepared, and Ti-O-C and S-C bonds were existing among Bi2S3, TiO2 as well as RGO. Furthermore, the photocatalytic ability of Bi2S3-TiO2-RGO composites was excellent under visible light due to its responding to the whole visible light region, low recombination rate of photogenerated electron–hole pairs and relatively negative conduction band. Rh B photocatalytic degradation rate was 99.5% after 50[Formula: see text]min and still could reach 98.4% after five cycles. Finally, a formation mechanism as well as a photocatalytic mechanism of Bi2S3-TiO2-RGO composites were proposed based on the experimental results.

scholarly journals Preparation of g-C3N4/MoS2 Composite Material and Its Visible Light Catalytic Performance

2021 ◽  
Author(s):  
Yu Fan ◽  
Yan-ning Yang ◽  
Chen Ding
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Photogenerated Electron ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Calcination Method

Abstract The g-C3N4 nanosheet was prepared by calcination method, the MoS2 nanosheet was prepared by hydrothermal method. The g-C3N4/MoS2 composites were prepared by ultrasonic composite in anhydrous ethanol. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-Vis), and photoluminescence (PL) techniques were used to characterize the materials. The photocatalytic degradation of Rhodamine B (Rh B) by g-C3N4/MoS2 composites with different mass ratios was investigated under visible light. The results show that a small amount of MoS2 combined with g-C3N4 can significantly improve photocatalytic activity. The g-C3N4/MoS2 composite with a mass ratio of 1:8 has the highest photocatalytic activity, and the degradation rate of Rh B increases from 50% to 99.6%. The main reason is that MoS2 and g-C3N4 have a matching band structure. The separation rate of photogenerated electron-hole pairs is enhanced. So the g-C3N4/MoS2 composite can improve the photocatalytic activity. The photocatalytic mechanism was proposed through the active matter capture experiment.

scholarly journals Core-Shell Heterostructured and Visible-Light-Driven Titanoniobate/TiO2 Composite for Boosting Photodegradation Performance

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1503 ◽  
Author(s):  
Chao Liu ◽  
Xin Gao ◽  
Zitong Han ◽  
Yao Sun ◽  
Yue Feng ◽  
...  
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Environmental Remediation ◽  
Synergistic Effects ◽  
Light Response ◽  
Core Shell ◽  
Photogenerated Electrons ◽  
Visible Light Driven ◽  
Degradation Activity ◽  
Calcination Method

Herein, we report a one-dimensional (1D) S-doped K3Ti5NbO14@TiO2 (STNT) core-shell heterostructured composite with an enhanced photocatalytic degradation activity under visible light, which was prepared by a simple reassembly-calcination method using thiourea as the S source. The anisotropically shaped rods are favorable for the rapid transport of photogenerated charge carriers. The substitution of Ti4+ by S6+ is primarily incorporated into the lattice of the TiO2 shell so as to create an intra-band-gap state below the conduction band (CB) position, giving rise to Ti−O−S bonds and thus the visible light response. The presence of electron-deficient S atoms is of benefit to the decreased recombination rate of photogenerated electrons and holes by capturing electrons (e−). Meanwhile, a tight close interface between K3Ti5NbO14 and TiO2 was formed to achieve a nano-heterojunction structure, leading to the fostered separation of its interfacial photogenerated electrons and holes. The visible-light-driven photocatalytic degradation of methylene blue (MB) by STNT composites is higher than that by pure K3Ti5NbO14, owing to the synergistic effects of S doping and heterojunction. A possible photocatalytic mechanism was proposed with a reasonable discussion. This work may provide an insight into constructing highly efficient core-shell photocatalysts used toward sustainable environmental remediation and resource shortages.

scholarly journals Synthesis of Z-scheme g-C3N4/V2O5photocatalyst with high activity under visible light

2021 ◽  
Vol 63 (11) ◽  
pp. 42-46
Author(s):  
Hung Thanh Tung Mai ◽  
◽  
Thi Hong Ngoc Doan ◽  
Ngoc Kim Tuyen Nguyen ◽  
Minh The Do ◽  
...  
Keyword(s):  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Photogenerated Electron ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Photocatalytic Activities ◽  
Calcination Method ◽  
The Individual

Direct Z-scheme g-C3N4/V2O5 photocatalysts were prepared through a sonication-assisted calcination method. The obtained samples were characterised by X-ray diffraction (XRD),Ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis-DRS), Scanning electron microscope (SEM), andPhotoluminescence spectroscopy (PL). Oxidations of tetracycline hydrochloride (TC) were employed to evaluate the photocatalytic activities of the obtained g-C3N4/V2O5materials. Different weight ratios (5, 10, 15, and 20%) of g-C3N4/V2O5 loaded composites were prepared, in which a 15% (CV-15) loaded composite was found to show optimal catalytic performance for the reaction. The degradation conversation of TC has achieved approximately 79.67% in CV-15 after a 2-hour reaction. g-C3N4/V2O5 photocatalystwas more active than the individual g-C3N4 and V2O5 materials, which could be attributed to the efficient separation of photogenerated electron-hole pairs shown in the photocatalytic mechanism of TC degradation.

Oxygen vacancy induced superior visible-light-driven photo-catalytic performance in the BiOCl homojunction

2020 ◽  
Vol 4 (8) ◽  
pp. 2314-2324 ◽  
Author(s):  
Siying Niu ◽  
Ruoyu Zhang ◽  
Chongfeng Guo
Keyword(s):  
Oxygen Vacancy ◽  
Visible Light ◽  
Oxygen Vacancies ◽  
Catalytic Performance ◽  
Catalytic Degradation ◽  
Electron Hole ◽  
Effective Separation ◽  
Visible Light Driven

The black BiOCl homojunction with oxygen vacancies has a wide absorption range and results in effective separation of photo-generated electron–hole pairs, which contribute to its superior visible-light-driven photo-catalytic degradation and disinfection ability.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

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.

Enhanced visible-active photocatalytic behaviors observed in Mn-doped BiFeO3

2018 ◽  
Vol 32 (17) ◽  
pp. 1850185 ◽  
Author(s):  
Yun-Hui Si ◽  
Yu Xia ◽  
Ya-Yun Li ◽  
Shao-Ke Shang ◽  
Xin-Bo Xiong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Mn Doped ◽  
Hole Recombination ◽  
Narrow Band Gap Semiconductors

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.

scholarly journals Silver Orthophosphate Immobilized on Flaky Layered Double Hydroxides as the Visible-Light-Driven Photocatalysts

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Xianlu Cui ◽  
Yaogang Li ◽  
Qinghong Zhang ◽  
Hongzhi Wang
Keyword(s):  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Visible Light Driven ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Acid Red G

Flaky layered double hydroxide (FLDH) was prepared by the reconstruction of its oxide in alkali solution. The composites with FLDH/Ag3PO4mass ratios at 1.6 : 1 and 3 : 1 were fabricated by the coprecipitation method. The powders were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscope, and UV-vis diffuse reflectance spectroscopy. The results indicated that the well-distributed Ag3PO4in a fine crystallite size was formed on the surface of FLDH. The photocatalytic activities of the Ag3PO4immobilized on FLDH were significantly enhanced for the degradation of acid red G under visible light irradiation compared to bare Ag3PO4. The composite with the FLDH/Ag3PO4mass ratio of 3 : 1 showed a higher photocatalytic efficiency.

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