Perovskite-type LaFeO3: Photoelectrochemical Properties and Photocatalytic Degradation of Organic Pollutants Under Visible Light Irradiation

Perovskite-type oxides lanthanum ferrite (LaFeO3) photocatalysts were successfully prepared by a facile and cost-effective sol-gel method using La(NO)3 and Fe(NO)3 as metal ion precursors and citric acid as a complexing agent at different calcination temperatures. The properties of the resulting LaFeO3 samples were characterized by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDXS), UV-Vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectra (IR), transmission electron microscopy (TEM), N2 adsorption/desorption and photoelectrochemical tests. The photoactivity of the LaFeO3 samples was tested by monitoring the photocatalytic degradation of Rhodamine B (RhB) and 4-chlorophenol (4-CP) under visible light irradiation, the highest photocatalytic activity was found for LaFeO3 calcined at 700 °C, which attributed to the relatively highest surface area (10.6 m2/g). In addition, it was found from trapping experiments that the reactive species for degradation were superoxide radical ions (O2−) and holes (h+). Photocurrent measurements and electrochemical impedance spectroscopy (EIS) proved the higher photo-induced charge carrier transfer and separation efficiency of the LaFeO3 sample calcined at 700 °C compared to that that calcined at 900 °C. Band positions of LaFeO3 were estimated using the Mott-Schottky plots, which showed that H2 evolution was not likely.

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Preparation of BiXY(2-X)O3 and its Photocatalytic Degradation of Molasses Fermentation Wastewater under Visible-Light Irradiation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.287-290.1640 ◽

2011 ◽

Vol 287-290 ◽

pp. 1640-1645 ◽

Cited By ~ 5

Author(s):

Min Guang Fan ◽

Zu Zeng Qin ◽

Zi Li Liu ◽

Tong Ming Su

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Photocatalytic Degradation ◽

Visible Light Irradiation ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance ◽

Diffuse Reflectance Spectroscopy ◽

Active Oxygen Species ◽

Light Irradiation ◽

X Ray

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.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.335-336.1385 ◽

2011 ◽

Vol 335-336 ◽

pp. 1385-1390 ◽

Cited By ~ 1

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.

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Photocatalytic degradation of deoxynivalenol over dendritic-like α-Fe2O3 under visible light irradiation

Toxins ◽

10.3390/toxins11020105 ◽

2019 ◽

Vol 11 (2) ◽

pp. 105 ◽

Cited By ~ 14

Author(s):

Huiting Wang ◽

Jin Mao ◽

Zhaowei Zhang ◽

Qi Zhang ◽

Liangxiao Zhang ◽

...

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Photocatalytic Degradation ◽

Visible Light Irradiation ◽

Photoelectron Spectroscopy ◽

High Performance ◽

Synthesis Method ◽

Light Irradiation ◽

Trichothecene Mycotoxin ◽

X Ray

Deoxynivalenol (DON) is a secondary metabolite produced by Fusarium, which is a trichothecene mycotoxin. As the main mycotoxin with high toxicity, wheat, barley, corn and their products are susceptible to contamination of DON. Due to the stability of this mycotoxin, traditional methods for DON reduction often require a strong oxidant, high temperature and high pressure with more energy consumption. Therefore, exploring green, efficient and environmentally friendly ways to degrade or reduce DON is a meaningful and challenging issue. Herein, a dendritic-like α-Fe2O3 was successfully prepared using a facile hydrothermal synthesis method at 160 °C, which was systematically characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). It was found that dendritic-like α-Fe2O3 showed superior activity for the photocatalytic degradation of DON in aqueous solution under visible light irradiation (λ > 420 nm) and 90.3% DON (initial concentration of 4.0 μg/mL) could be reduced in 2 h. Most of all, the main possible intermediate products were proposed through high performance liquid chromatography-mass spectrometry (HPLC-MS) after the photocatalytic treatment. This work not only provides a green and promising way to mitigate mycotoxin contamination but also may present useful information for future studies.

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Photocatalytic properties of p-n heterojunction Ag2CO3/Ag3PO4/Ni thin films under visible light

Functional Materials Letters ◽

10.1142/s1793604719500851 ◽

2019 ◽

Vol 12 (06) ◽

pp. 1950085 ◽

Cited By ~ 1

Author(s):

Di Zhao ◽

Xuezheng An ◽

Yaxian Sun ◽

Guihua Li ◽

Hongyan Liu ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Visible Light ◽

Visible Light Irradiation ◽

Diffuse Reflectance ◽

Diffuse Reflectance Spectroscopy ◽

Light Irradiation ◽

X Ray Diffraction ◽

X Ray ◽

Photodegradation Efficiency

p-n heterojunction Ag2CO3/Ag3PO4/Ni thin films were prepared by electrochemical co-deposition. The surface morphology and structural properties of the thin films were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic (PC) properties of the Ag2CO3/Ag3PO4/Ni composite thin films were investigated by their ability to degrade rhodamine B (RhB) and Congo red (CR) under visible light irradiation. The results showed that the photodegradation efficiency of RhB by an Ag2CO3/Ag3PO4/Ni thin film under visible-light irradiation for 30[Formula: see text]min (98.84%) was 2.64 times higher than that of an Ag3PO4/Ni thin film and 3.44 times higher than of an Ag2CO3/Ni thin film. The presence of a [Formula: see text]-[Formula: see text] heterojunction greatly increased the charge conductivity of the film and its ability to photocatalytically reduce dissolved oxygen, which are the main reasons for the improved PC performance of the Ag2CO3/Ag3PO4/Ni films.

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Noble metal-modified titania with visible-light activity for the decomposition of microorganisms

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.77 ◽

2018 ◽

Vol 9 ◽

pp. 829-841 ◽

Cited By ~ 11

Author(s):

Maya Endo ◽

Zhishun Wei ◽

Kunlei Wang ◽

Baris Karabiyik ◽

Kenta Yoshiiri ◽

...

Keyword(s):

Antibacterial Activity ◽

Visible Light ◽

Noble Metal ◽

Visible Light Irradiation ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Light Irradiation ◽

Localized Surface Plasmon ◽

Mycelium Growth ◽

X Ray

Commercial titania photocatalysts were modified with silver and gold by photodeposition, and characterized by diffuse reflectance spectroscopy (DRS), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM). It was found that silver co-existed in zero valent (core) and oxidized (shell) forms, whereas gold was mainly zero valent. The obtained noble metal-modified samples were examined with regard to antibacterial (Escherichia coli(E. coli)) and antifungal (Aspergillus niger(A. niger),Aspergillus melleus(A. melleus),Penicillium chrysogenum(P. chrysogenum),Candida albicans(C. albicans)) activity under visible-light irradiation and in the dark using disk diffusion, suspension, colony growth (“poisoned food”) and sporulation methods. It was found that silver-modified titania, besides remarkably high antibacterial activity (inhibition of bacterial proliferation), could also decompose bacterial cells under visible-light irradiation, possibly due to an enhanced generation of reactive oxygen species and the intrinsic properties of silver. Gold-modified samples were almost inactive against bacteria in the dark, whereas significant bactericidal effect under visible-light irradiation suggested that the mechanism of bacteria inactivation was initiated by plasmonic excitation of titania by localized surface plasmon resonance of gold. The antifungal activity tests showed efficient suppression of mycelium growth by bare titania, and suppression of mycotoxin generation and sporulation by gold-modified titania. Although, the growth of fungi was hardly inhibited through disc diffusion (inhibition zones around discs), it indicates that gold does not penetrate into the media, and thus, a good stability of plasmonic photocatalysts has been confirmed. In summary, it was found that silver-modified titania showed superior antibacterial activity, whereas gold-modified samples were very active against fungi, suggesting that bimetallic photocatalysts containing both gold and silver should exhibit excellent antimicrobial properties.

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Synthesis of BiSI/Ag2CO3 Composite Material for Photocatalytic Degradation of Rhodamine B under Visible Light

10.21203/rs.3.rs-883480/v1 ◽

2021 ◽

Author(s):

Rui Zhang ◽

ziyin chen ◽

Chen Zhao ◽

Kunlin Zeng ◽

Lu Cai ◽

...

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Photocatalytic Degradation ◽

Rhodamine B ◽

Photocatalytic Performance ◽

Electrochemical Impedance ◽

Diffuse Reflectance Spectroscopy ◽

Mass Ratio ◽

X Ray ◽

Visible Light Driven

Abstract A novel binary BiSI/Ag2CO3 photocatalyst with excellent visible light-driven photocatalytic performance was prepared. The products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) and electrochemical impedance spectroscopy (EIS). The photocatalytic activity of the samples were evaluated by photocatalytic degradation of rhodamine B(RhB) under the irradiation of visible light. The results showed that the BiSI improves the photocatalytic activity of BiSI/Ag2CO3. Moreover, when the mass ratio of BiSI in BiSI/Ag2CO3 composites was 40%, the as-prepared BiSI/Ag2CO3 composite exhibited the best photocatalytic activity for degrading RhB. Finally, the possible mechanism for photodegradation over the BiSI/Ag2CO3 composites is also proposed.

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Synergistic Effect on Photocatalytic Activity of Co-Doped NiTiO3/g-C3N4 Composites under Visible Light Irradiation

Catalysts ◽

10.3390/catal10111332 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1332

Author(s):

Duc Quang Dao ◽

Thi Kim Anh Nguyen ◽

Thanh-Truc Pham ◽

Eun Woo Shin

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Visible Light Irradiation ◽

Electrochemical Impedance ◽

Lattice Structure ◽

Light Irradiation ◽

X Ray ◽

Co Doping ◽

Composite Photocatalysts ◽

Co Doped

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.

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A Comparative Study on the Role of Precursors of Graphitic Carbon Nitrides for the Photocatalytic Degradation of Direct Red 81

Materials Science Forum ◽

10.4028/www.scientific.net/msf.807.101 ◽

2014 ◽

Vol 807 ◽

pp. 101-113 ◽

Cited By ~ 5

Author(s):

J. Theerthagiri ◽

R.A. Senthil ◽

J. Madhavan ◽

B. Neppolian

Keyword(s):

Particle Size ◽

Photocatalytic Activity ◽

Visible Light ◽

Photocatalytic Degradation ◽

Visible Light Irradiation ◽

Carbon Nitride ◽

Light Irradiation ◽

X Ray Diffraction ◽

X Ray ◽

Carbon Nitrides

The graphitic carbon nitride (g-C3N4) materials have been synthesized from nitrogen rich precursors such as urea and thiourea by directly heating at 520 °C for 2 h. The as-synthesized carbon nitride samples were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis) absorption spectroscopy, photoluminescence (PL) and particle size analysis. The photoelectrochemical measurements were performed using several on-off cycles under visible-light irradiation. The x-ray diffraction peak is broader which indicates the fine powder nature of the synthesized materials. The estimated crystallite size of carbon nitrides synthesized from urea (U-CN) and thiourea (T-CN) are 4.0 and 4.4 nm respectively. The particle size of U-CN and T-CN were analysed by particle size analyser and were found to be 57.3 and 273.3 nm respectively. The photocatalytic activity for the degradation of the textile dye namely, direct red-81 (DR81) using these carbon nitrides were carried out under visible light irradiation. In the present investigation, a comparison study on the carbon nitrides synthesized from cheap precursors such as urea and thiourea for the degradation of DR81 has been carried out. The results inferred that U-CN exhibited higher photocatalytic activity than T-CN. The photoelectrochemical studies confirmed that the (e--h+) charge carrier separation is more efficient in U-CN than that of T-CN and therefore showed high photocatalytic degradation. Further, the smaller particle size of U-CN is also responsible for the observed degradation trend.

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Design and fabrication of Ag3VO4/g-C3N4 heterostructure photocatalyst for enhanced visible light degradation of various organic pollutants

10.21203/rs.3.rs-329610/v1 ◽

2021 ◽

Author(s):

N Sujatha ◽

M Meenachi ◽

S Mohammed Harshulkhanb ◽

H.H Hegazy

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Visible Light Irradiation ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Light Irradiation ◽

X Rays ◽

Hydrothermal Route ◽

X Ray ◽

Visible Light Degradation

Abstract In later years, numerous viable photocatalysts have been created in order to illuminate the issues of natural toxins. In this work, heterostructured photocatalysts Ag3VO4/g-C3N4 were prepared by effortless hydrothermal route in order to anchor Ag3VO4 on the surface of the g-C3N4 nanosheets. The prepared samples were fairly characterized using X-ray diffraction (XRD), Energy dispersive analysis of X-rays (EDAX), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-DRS), photoluminescence, and X-ray photoelectron spectroscopy (XPS) techniques. The photocatalytic activity of the samples was evaluated by degrading malachite green (MG) and 2,4 dimethyl phenol (DMP) in aqueous solution under visible light irradiation. Compared with Ag3VO4 and g-C3N4, the heterojuncted photocatalyst 50 wt% Ag3VO4/g-C3N4 exhibits the best activity such as high degradation efficiency (99%), high apparent constant (0.0923 min− 1) and long term stability towards DMP under visible light irradiation. The development of a phase scheme heterojunction between Ag3VO4 and g-C3N4 improved the photocatalytic efficiency of Ag3VO4/g-C3N4 composites. Furthermore, the porous structure of g-C3N4 and the effect of Ag surface plasmon resonance (SPR) speed up the isolation and transfer of electron-hole pairs, reducing the likelihood of recombination.

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