scholarly journals Preparation, Characterization, and Photocatalytic Applications of MWCNTs/TiO2Composite

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ahmed M. Kamil ◽  
Falah H. Hussein ◽  
Ahmed F. Halbus ◽  
Detlef W. Bahnemann
Keyword(s):  
Photocatalytic Activity ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Multiwall Carbon Nanotubes ◽  
Photogenerated Electron ◽  
Drying Process ◽  
Electron Hole ◽  
Activity Performance ◽  
Photocatalytic Applications ◽  
Multiwall Carbon

The multiwall carbon nanotubes (MWCNTs)/titanium dioxide (P25) composite in different ratios was prepared using simple evaporation and drying process. The composite was characterized by Raman spectroscopy, X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy, and scanning electron microscopy (SEM). The photocatalytic activity of this composite was investigated using degradation of the Bismarck brown R dye (BBR). An optimal MWCNTs/TiO2ratio of 0.5% (w/w) was found to achieve the maximum rate of BBR degradation. It was observed that the composite exhibits enhanced photocatalytic activity compared with TiO2. The enhancement in photocatalytic activity performance of the MWCNTs/P25 composite is explained in terms of recombination of photogenerated electron-hole pairs. In addition, MWCNTs act as a dispersing support to control the morphology of TiO2particles in the MWCNTs/TiO2composite.

scholarly journals Synthesis and photocatalytic activity of ZnO/CuO composite for the degradation of methyl blue under vilsible light iradiation

2020 ◽  
Vol 9 (3) ◽  
pp. 94-100
Author(s):  
Kim Nguyen Van ◽  
Nga Nguyen Thi Viet ◽  
Tuyen Vo Thi Thanh ◽  
Vien Vo
Keyword(s):  
Photocatalytic Activity ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Photogenerated Electron ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Microwave System ◽  
Direct Formation

Composite ZnO/CuO was prepared by direct formation of ZnO from Zn(OOCCH3)2 precursor in the presence of CuO with the assistant of the microwave system. The obtained composite was characterized by X-Ray Diffraction (XRD) and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-vis DRS), which shows that the composite with a bandgap of 3.27 eV contains two components, ZnO and CuO. The photocatalytic activity of ZnO/CuO was assessed by the degradation of methylene blue (MB) in water under visible light, shows that the photocatalytic activity for the ZnO/CuO composite was remarkably improved compared to single ZnO and CuO. This result is attributed to the reduced recombination rate of photogenerated electron-hole pairs by the presence of CuO in the composite, therefore photocatalysis activity increases.

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.

scholarly journals Fabricating Nano-Sized BiVO4/InVO4/g-C3N4 Photocatalysts for Efficient Degradation of Acid Blue 92 Azo Dye

2018 ◽  
Vol 43 (2) ◽  
pp. 112-120 ◽  
Author(s):  
Mahboubeh Tasviri ◽  
Samin Bargozideh
Keyword(s):  
Photocatalytic Activity ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Life Time ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Ultrasonic Assisted ◽  
Acid Blue ◽  
Hydrothermal Methods

BiVO4/InVO4 and BiVO4/InVO4/g-C3N4 were prepared by hydrothermal and ultrasonic-assisted hydrothermal methods respectively. All prepared samples were characterised by X-ray diffraction, scanning electron microscopy and UV-Vis diffuse reflectance spectroscopy. The photocatalytic activity of the prepared catalysts was determined by degradation of Acid Blue 92 (AB92) under visible light. The rate constant and efficiency of AB92 degradation over BiVO4/InVO4/g-C3N4 was higher than that over BiVO4/InVO4 which indicates better photocatalytic activity of BiVO4/InVO4/g-C3N4. This enhancement can be attributed to the suitable dispersion of BiVO4 and InVO4 particles on the g-C3N4 surface. Furthermore, the conduction band and valence band edge potentials of InVO4, BiVO4 and g-C3N4 extend the life-time of electron–hole pairs which is beneficial for the improvement of photocatalytic efficiency.

scholarly journals Preparation and Photocatalytic Properties of N-Doped Graphene/TiO2 Composites

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jing Liu ◽  
Kun-Yu Chen ◽  
Jie Wang ◽  
Min Du ◽  
Zheng-Yang Gao ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Adsorption Capacity ◽  
Ultraviolet Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Photogenerated Electron ◽  
Light Irradiation ◽  
Electron Hole ◽  
X Ray ◽  
Ultraviolet Light Irradiation ◽  
Doped Graphene

N-doped graphene (NG)/TiO2 composites were prepared by a two-step hydrothermal method using HF as the surface etchant and urea as the nitrogen source. The morphology, structure, and bonding conditions of the NG/TiO2 composites were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and photoluminescence (PL) spectroscopy. The effects of NG on the lifetime of photogenerated electron-hole pairs, adsorption capacity, and photocatalytic activity of the composite photocatalysts were also investigated. The photocatalytic activity was evaluated under ultraviolet light and sunlight irradiation. The recovery testing was completed under ultraviolet light irradiation. The results show that TiO2 was uniformly loaded on the NG surface by chemical bonding. The introduction of NG effectively inhibited the recombination of photogenerated electron-hole pairs and improved both the adsorption capacity and photocatalytic activity of the composites. The 7 wt % NG/TiO2 showed the best adsorption capacity of methyl orange (MO). The best photocatalytic activity occurred for 5 wt % NG/TiO2 composites, and after four recovery tests, the photocatalytic degradation of MO under 60 min ultraviolet light irradiation exceeded 90%.

SnO2 nanoparticles: synthesis, characterization and photocatalytic activity

2021 ◽  
Vol 11 (1) ◽  
pp. 17-22
Author(s):  
Thao Ho Hoang Nhu ◽  
Giang Tran Chau ◽  
Nhat Nguyen Bich ◽  
Han Le Thi Ngoc ◽  
Trinh Nguyen Ai ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Sno2 Nanoparticles ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Heat Treated ◽  
Naoh Solution

SnO2 nanoparticles have been synthesized using precipitation method and heat treatment. Firstly, SnCl4.5H2O was reacted with NaOH solution, and than the precipitate heat treated at 350 oC, 450 oC and 550 oC. The obtained materials were characterized by X-Ray diffraction (XRD), infrared spectra (IR), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The photocatalytic degradation of rhodamine B (RhB) using SnO2 nanoparticles was investigated. The results show that the SnO2 nanoparticles exhibited a significantly enhanced photocatalytic activity. The photoactivity of SnO2 nanoparticles photocatalysts can be ascribed to the enhanced electron-hole separation.

scholarly journals Rationally Designed Bi2M2O9 (M = Mo/W) Photocatalysts with Significantly Enhanced Photocatalytic Activity

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7334
Author(s):  
Fangzhi Wang ◽  
Xiaoyan Zhou ◽  
Jing Li ◽  
Qiuyue He ◽  
Ling Zheng ◽  
...  
Keyword(s):  
Diffuse Reflectance ◽  
Photocatalytic Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
Photogenerated Electron ◽  
Reflectance Spectroscopy ◽  
Active Species ◽  
Photocatalytic Efficiency ◽  
Electron Hole ◽  
Radical Trapping ◽  
Structure Morphology

Novel Bi2W2O9 and Bi2Mo2O9 with irregular polyhedron structure were successfully synthesized by a hydrothermal method. Compared to ordinary Bi2WO6 and Bi2MoO6, the modified structure of Bi2W2O9 and Bi2Mo2O9 were observed, which led to an enhancement of photocatalytic performance. To investigate the possible mechanism of enhancing photocatalytic efficiency, the crystal structure, morphology, elemental composition, and optical properties of Bi2WO6, Bi2MO6, Bi2W2O9, and Bi2Mo2O9 were examined. UV-Vis diffuse reflectance spectroscopy revealed the visible-light absorption ability of Bi2WO6, Bi2MO6, Bi2W2O9, and Bi2Mo2O9. Photoluminescence (PL) and photocurrent indicated that Bi2W2O9 and Bi2Mo2O9 pose an enhanced ability of photogenerated electron–hole pairs separation. Radical trapping experiments revealed that photogenerated holes and superoxide radicals were the main active species. It can be conjectured that the promoted photocatalytic performance related to the modified structure, and a possible mechanism was discussed in detail.

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 Template-Free Synthesis of Star-Like ZrO2 Nanostructures and Their Application in Photocatalysis

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xue-Yu Tao ◽  
Jie Ma ◽  
Rui-Lin Hou ◽  
Xiang-Zhu Song ◽  
Lin Guo ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Process ◽  
Photocatalytic Property ◽  
Reflectance Spectroscopy ◽  
Raw Material ◽  
Narrow Bandgap ◽  
Excellent Photocatalytic Activity ◽  
Template Free

Star-like nano-ZrO2 has been synthesized using Zr(NO3)4·5H2O as zirconium source by a hydrothermal process without any template and surfactant. The structure of the as-prepared ZrO2 powder was investigated by multiple advanced analytical methods. The results showed that CH3COO− and NO3− had great effects on the formation of star-like ZrO2 nanostructures. The as-prepared ZrO2 had a superior catalytic activity, and the reason for it was analyzed by UV-Vis diffuse reflectance spectroscopy. The effect of raw material ratios on the photocatalytic property of ZrO2 was studied. The synthesized ZrO2 showed a narrow bandgap (3.50–3.85 eV) and an excellent photocatalytic activity, and the degradation of RhB was up to nearly 100% in 30 min with this photocatalyst.

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