scholarly journals The Effect of the Reducing Sugars in the Synthesis of Visible-Light-Active Copper(I) Oxide Photocatalyst

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1149
Author(s):  
Szilvia Fodor ◽  
Lucian Baia ◽  
Kornélia Baán ◽  
Gábor Kovács ◽  
Zsolt Pap ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Structural Characteristics ◽  
Reducing Agent ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Methyl Orange Degradation ◽  
X Ray ◽  
Visible Light Active

In the present work, shape tailored Cu2O microparticles were synthesized by changing the nature of the reducing agent and studied subsequently. d-(+)-glucose, d-(+)-fructose, d-(+)xylose, d-(+)-galactose, and d-(+)-arabinose were chosen as reducing agents due to their different reducing abilities. The morpho-structural characteristics were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS), while their photocatalytic activity was evaluated by methyl orange degradation under visible light (120 min). The results show that the number of carbon atoms in the sugars affect the morphology and particle size (from 250 nm to 1.2 µm), and differences in their degree of crystallinity and photocatalytic activity were also found. The highest activity was observed when glucose was used as the reducing agent.

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.

Visible-Light-Induced Photocatalytic Activity of Boron-Doped BiVO4

2014 ◽  
Vol 809-810 ◽  
pp. 890-894
Author(s):  
Dan Li ◽  
Lian Wei Shan ◽  
Gui Lin Wang ◽  
Li Min Dong ◽  
Wei Li ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Reflectance Spectroscopy ◽  
Scheelite Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Boron Doped

Boron-BiVO4 samples were synthesized by sol-gel method. They were characterized by UV-vis diffuse reflectance spectroscopy, X-ray diffraction. Photocatalytic activity of the obtained BiVO4 samples was investigated through degrading methylene blue (MB). The results reveal that boron-BiVO4 catalysts have monoclinic scheelite structure. The BiVO4 and Co-BiVO4 photocatalysts were responsive to visible light. Co-BiVO4 photocatalyst showed higher photocatalytic activity than pure BiVO4, resulting in the significantly improved efficiency of degradation of MB.

scholarly journals Improved Visible Light Photocatalytic Activity for TiO2Nanomaterials by Codoping with Zinc and Sulfur

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Qianzhi Xu ◽  
Xiuying Wang ◽  
Xiaoli Dong ◽  
Chun Ma ◽  
Xiufang Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Sunlight Irradiation ◽  
X Ray ◽  
Transmission Electron ◽  
Photoinduced Charge

S/Zn codoped TiO2nanomaterials were synthesized by a sol-gel method. X-ray diffraction, UV-vis diffuse reflectance spectroscopy, transmission electron microscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy were used to characterize the morphology, structure, and optical properties of the prepared samples. The introduction of Zn and S resulted in significant red shift of absorption edge for TiO2-based nanomaterials. The photocatalytic activity was evaluated by degrading reactive brilliant red X-3B solution under simulated sunlight irradiation. The results showed S/Zn codoped TiO2exhibited higher photocatalytic activity than pure TiO2and commercial P25, due to the photosynergistic effect of obvious visible light absorption, efficient separation of photoinduced charge carriers, and large surface area. Moreover, the content of Zn and S in the composites played important roles in photocatalytic activity of TiO2-based nanomaterials.

Characterization and Visible-Light Photocatalytic Activity of Nano-Bi2MoO6 Catalysts Prepared by Hydrothermal Process

2011 ◽  
Vol 117-119 ◽  
pp. 803-806
Author(s):  
Pei Song Tang ◽  
Hai Feng Chen ◽  
Feng Cao ◽  
Guo Xiang Pan ◽  
Min Hong Xu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Degussa P25 ◽  
Uv Visible ◽  
Visible Light Photocatalytic

The Nano-Bi2MoO6was prepared using Bi(NO3)3•5H2O and Na2MoO4•2H2O as starting materials by a hydrothermal process. The prepared Bi2MoO6product was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). It was found that the prepared nano-Bi2MoO6show narrow band gap of 2.88 eV. Consequently, the prepared nano-Bi2MoO6show high visible-light photocatalytic activity for decomposition of Rhodamine B in comparison with the commercial Degussa P25, which was ascribed to the visible-light absorption.

scholarly journals Cu-doped TiO2 brookite photocatalyst with enhanced visible light photocatalytic activity

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yunling Zou ◽  
Xianshou Huang ◽  
Tao Yu ◽  
Xiaoqiang Tong ◽  
Yan Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Photocatalytic

Abstract Cu-doped TiO2 having a brookite phase and showing enhanced visible light photocatalytic activity was synthesized using a mild solvothermal method. The as-prepared samples were characterized by various techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy. Photocatalytic activity of Cu-doped brookite TiO2 nanoparticles was evaluated by photodegradation of methylene blue under visible light irradiation. The X-ray diffraction analysis showed that the crystallite size of Cu-doped brookite TiO2 samples decreased with the increase of Cu concentration in the samples. The UV-Vis diffuse reflectance spectroscopy analysis of the Cu-doped TiO2 samples showed a shift to lower energy levels in the band gap compared with that of bare phase brookite TiO2. Cu doped brookite TiO2 can obviously improve its visible light photocatalytic activity because of Cu ions acting as electron acceptors and inhibiting electron-hole recombination. The brookite TiO2 sample with 7.0 wt.% Cu showed the highest photocatalytic activity and the corresponding degradation rate of MB (10 mg/L) reached to 87 % after visible light illumination for 120 min, much higher than that of bare brookite TiO2 prepared under the same conditions (78 %).

scholarly journals Synthesis, Characterization, and Photocatalytic Activity of Microspheres Functionalized with Porphyrin

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Jin-Hua Cai ◽  
Jin-Wang Huang ◽  
Han-Cheng Yu ◽  
Liang-Nian Ji
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
Model Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

In order to utilize visible light more efficiently in the photocatalytic reaction, microspheres sensitized by 5-(4-allyloxy)phenyl-10,15,20-tri(4-methylphenyl)porphyrin (APTMPP) were prepared and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nitrogen physisorption, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and UV-vis diffuse reflectance spectroscopy, and so forth, The characterization results indicated that APTMPP-MPS- was composed of the anatase crystal phase. The morphology of the composite materials was spheriform with size of 0.3–0.7 μm and the porphyrin was chemisorbed on the surface of through a Si–O–Ti bond. The photooxidation ofα-terpinene was employed as the model reaction to evaluate the photocatalytic activity of APTMPP-MPS- microspheres under visible light. The results indicated that the photodegradation ofα-terpinene was significantly enhanced in the presence of the APTMPP-MPS- compared with the nonmodified under visible light.

scholarly journals Magnetically Recoverable TiO2/SiO2/γ-Fe2O3/rGO Composite with Significantly Enhanced UV-Visible Light Photocatalytic Activity

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 2996 ◽  
Author(s):  
Reyhaneh Kaveh ◽  
Maryam Mokhtarifar ◽  
Mojtaba Bagherzadeh ◽  
Andrea Lucotti ◽  
Maria Vittoria Diamanti ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Active Sites ◽  
Diffuse Reflectance Spectroscopy ◽  
Charge Carriers ◽  
Photocatalytic Efficiency ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
X Ray ◽  
Uv Visible

In this paper, we report the preparation of a new composite (TiO2/SiO2/γ-Fe2O3/rGO) with a high photocatalytic efficiency. The properties of the composite were examined by different analyses, including X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), photoluminescence (PL), UV-Visible light diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman, vibrating-sample magnetometer (VSM), and nitrogen gas physisorption (BET) studies. The photocatalytic efficiency of the proposed composite was evaluated by the degradation of methylene blue under UV and visible light, and the results were compared with titanium dioxide (TiO2), where degradation increased from 30% to 84% and 4% to 66% under UV and visible light, respectively. The significant increase in photocatalytic activity may be explained by the higher adsorption of dye on the surface of the composite and the higher separation and transfer of charge carriers, which in turn promote active sites and photocatalytic efficiency.

Preparation of Nanoparticulate ErFeO3 by Microwave Assisted Process and its Photocatalytic Activity

2014 ◽  
Vol 809-810 ◽  
pp. 140-143 ◽  
Author(s):  
Chao Wan Tang ◽  
Jia Ni Ying ◽  
Dong Jing Ni ◽  
Qian Yang ◽  
Li Mei Wu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance ◽  
Single Phase ◽  
Diffuse Reflectance Spectroscopy ◽  
High Photocatalytic Activity ◽  
Experimental Simulation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Visible

Using Er (NO3)3·5H2O and Fe (NO3)3·9H2O as major materials, the ErFeO3 nanoparticles were prepared by successive microwave processing and high temperature calcination. The samples were characterized by thermogravimetric and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). It was found that the single phase ErFeO3 can be obtained through the calcination of microwave processed ErFeO3 precursors at 800°C, and the resulting product was approximation flake of 20-80 nm. The visible-light photocatalytic activity of ErFeO3 nanoparticles was investigated in experimental simulation wastewater containing 10 mg/L methyl orange (MO). The results show that ErFeO3 nanoparticles appear high photocatalytic activity for the decomposition of MO under visible-light irradiation.

Synthesis of Nanocrystalline FeVO4 and Its Visible-Light Photocatalytic Activity

2012 ◽  
Vol 486 ◽  
pp. 124-128 ◽  
Author(s):  
Yi Tong ◽  
Pei Song Tang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Optical Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
Precipitation Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Average Grain Size ◽  
Visible Light Photocatalytic

The FeVO4 nanoparticles were synthesized by a precipitation process. The FeVO4 nanoparticles were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectroscopy (DRS). It was found that the prepared FeVO4 nanoparticles show an average grain size of 50-80 nm in diameter, and strong visible-light absorption with absorption onset of 515 nm, indicating a narrow optical band gap of 2.4 eV. Consequently, the FeVO4 nanoparticles show high visible-light photocatalytic activity for decomposition of methyl orange.

scholarly journals Visible Light-Driven Photocatalytic Activity of Magnetic Recoverable Ternary ZnFe2O4/rGO/g-C3N4 Nanocomposites

2020 ◽  
Vol 67 (4) ◽  
pp. 1082-1091
Author(s):  
Martin Tsvetkov ◽  
Elzhana Encheva ◽  
Albin Pintar ◽  
Maria Milanova
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Weight Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Driven ◽  
Physicochemical Methods ◽  
Green Model ◽  
Adsorption Desorption

ZnFe2O4/rGO/g-C3N4 ternary nanocomposite photocatalysts with different ZnFe2O4/g-C3N4 weight ratio (0.5, 0.75, 1) were prepared by a stepwise solvothermal method using ethylene glycol as the solvent. Physicochemical methods such as X-ray diffraction, UV-Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy were applied in order to characterize the composites. The formation of a meso-/macroporous structure with specific surface area between 67 and 77 m2 g–1 was confirmed by N2 adsorption/desorption. The bandgap of the composites was found to be lower (2.30 eV) than that of g-C3N4 (2.7 eV). In contrast to pure g-C3N4, the composites showed no fluorescence, i.e. no recombination of e–/h+ took place. All samples, including pure g-C3N4 and ZnFe2O4, were tested for adsorption and photocatalytic degradation of aqueous malachite green model solutions (10–5 M) under visible light irradiation (λ > 400 nm). The results show that the prepared nanocomposites have higher absorption and photocatalytic activity than the pristine g-C3N4 and ZnFe2O4 and can be successfully used for water purification from organic azo-dyes.

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