Visible Light-Driven BiVO4/TiO2 Composite Photocatalysts: Preparation Methods and Photocatalytic Performance

2015 ◽  
Vol 68 (8) ◽  
pp. 1268 ◽  
Author(s):  
Shuyun Wang ◽  
Wenjun Li ◽  
Feiwu Chen ◽  
Shaonan Gu ◽  
Zhidong Chang

BiVO4/TiO2 composite photocatalysts were successfully synthesised via different methods, and the physical and photophysical properties of the as-prepared photocatalysts were fully characterised by X-ray diffraction, scanning electron microscopy, field-emission transmission electron microscopy, energy dispersive spectroscopy, UV-vis diffuse reflectance spectroscopy, photoluminescence spectroscopy and Brunauer–Emmett–Teller (BET) surface area analysis. Methylene blue was selected as model pollutant to investigate the photocatalytic activity of BiVO4/TiO2 composite materials. The results reveal that BiVO4/TiO2 fabricated by different methods exhibits higher photocatalytic activity than pure BiVO4 and TiO2, and the coprecipitated BiVO4/TiO2 composite shows the best photocatalytic activity. The diffuse reflectance spectroscopy results demonstrated that the 20 wt-% coprecipitated BiVO4/TiO2 exhibited a significant, broad spectrum response not only between 400 and 500 nm but also from 500 to 800 nm wavelength.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yunling Zou ◽  
Xianshou Huang ◽  
Tao Yu ◽  
Xiaoqiang Tong ◽  
Yan Li ◽  
...  

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 %).


2015 ◽  
Vol 68 (10) ◽  
pp. 1562 ◽  
Author(s):  
Fengjun Zhang ◽  
Guosheng Xiao ◽  
Wei Lu ◽  
Tianye Wang ◽  
Limin Xuan ◽  
...  

Eu-Doped Bi2O3/CeO2 composites were successfully synthesized by a facile sol–gel–calcination route. The as-prepared composites were prepared with different molar ratios of Bi/Ce/Eu by the sol–gel route, and then calcined at 500°C for 2 h. The photocatalytic efficiencies of all composites were tested by degradation of methyl orange (MO) under visible light irradiation. The result suggested that the best composite is the one that was prepared with a Bi/Ce/Eu mole ratio of 8 : 8 : 1, and achieved a MO degradation rate of nearly 98.5 % within 2 h of irradiation. The as-prepared composites were characterized by X-ray diffraction, scanning electron microscopy, inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV-visible diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The X-ray diffraction and scanning electron microscopy results suggested that Eu doping may have led to some lattice distortion and particle aggregation that enhanced the photocatalytic activity of the photocatalyst. The UV-visible diffuse reflectance spectroscopy and photoluminescence spectroscopy results showed that Eu-doped Bi2O3/CeO2 exhibited higher visible light response properties and enhanced separation of the photogenerated electron–hole pairs, which is the main reason for the higher photocatalytic activity. In general, this study could provide a facile route to synthesize Eu-doped Bi2O3/CeO2 composites with enhanced photocatalytic activity by a sol–gel–calcination route for environmental purification.


2014 ◽  
Vol 809-810 ◽  
pp. 890-894
Author(s):  
Dan Li ◽  
Lian Wei Shan ◽  
Gui Lin Wang ◽  
Li Min Dong ◽  
Wei Li ◽  
...  

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xue-Yu Tao ◽  
Jie Ma ◽  
Rui-Lin Hou ◽  
Xiang-Zhu Song ◽  
Lin Guo ◽  
...  

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.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 206 ◽  
Author(s):  
Sher Lee ◽  
Chi-Jung Chang

Conductive polymers have been widely investigated in various applications. Several conductive polymers, such as polyaniline (PANI), polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) (PEDOT)), and polythiophene (PTh) have been loaded with various semiconductor nanomaterials to prepare the composite photocatalysts. However, a critical review of conductive polymer-based composite photocatalysts has not been available yet. Therefore, in this review, we summarized the applications of conductive polymers in the preparation of composite photocatalysts for photocatalytic degradation of hazardous chemicals, antibacterial, and photocatalytic hydrogen production. Various materials were systematically surveyed to illustrate their preparation methods, morphologies, and photocatalytic performances. The synergic effect between conductive polymers and semiconductor nanomaterials were observed for a lot of composite photocatalysts. The band structures of the composite photocatalysts can be analyzed to explain the mechanism of their enhanced photocatalytic activity. The incorporation of conductive polymers can result in significantly improved visible-light driven photocatalytic activity by enhancing the separation of photoexcited charge carriers, extending the light absorption range, increasing the adsorption of reactants, inhibiting photo-corrosion, and reducing the formation of large aggregates. This review provides a systematic concept about how conductive polymers can improve the performance of composite photocatalysts.


2020 ◽  
Vol 81 (5) ◽  
pp. 1080-1089
Author(s):  
Huan-Yan Xu ◽  
Dan Lu ◽  
Qu Tan ◽  
Xiu-Lan He ◽  
Shu-Yan Qi

Abstract Bismuth oxyhalides (BiOXs, X = Cl, Br and I) are emerging photocatalytic materials with unique layered structure, flexible band structure and superior photocatalytic activity. The purpose of this study was to develop a facile alcoholysis route to prepare BiOClxI1−x nanosheet solid solutions at room temperature. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), photoluminescence emission spectroscopy (PL) and Brunauer–Emmett–Teller (BET) surface area analyzer were used to characterize the as-prepared photocatalysts. These results revealed that two-dimension BiOClxI1−x nanosheet solid solutions could be obtained with high percentage of {001} crystal facets exposed. Moreover, the formation of solid solution could regularly change the optical absorption thresholds and band gaps of BiOClxI1−x photocatalysts. The photocatalytic experiments indicated that BiOCl0.75I0.25 exhibited the highest photocatalytic performance for the degradation of Rhodamine B (RhB) under simulated sunlight irradiation and the photocatalytic process followed a pseudo-first-order kinetic equation. A possible mechanism of RhB photodegradation over BiOClxI1−x solid solutions was proposed based on the structural properties of BiOClxI1−x solid solutions and RhB photosensitization.


2014 ◽  
Vol 881-883 ◽  
pp. 1101-1104 ◽  
Author(s):  
Min Jie Zhou ◽  
Peng Cui

In this work, flower-like ZnIn2S4 microspheres were synthesized using a solvothermal method. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and ultraviolet-visible diffuse reflectance spectroscopy (DRS) techniques. The photocatalytic activity of the ZnIn2S4 microspheres was investigated. The ZnIn2S4 microspheres exhibit much higher photocatalytic activity than pure P25 TiO2.


2012 ◽  
Vol 550-553 ◽  
pp. 196-199
Author(s):  
Ze Wan ◽  
Fa Mei Feng ◽  
Jian Zhang Li ◽  
Jin Jin He ◽  
Jun Bo Zhong ◽  
...  

This paper reveals that photocatalytic activity of Bi2O3 under visible light towards the decolorization of Methyl Orange solution can be greatly enhanced by doping Pr into the lattice of Bi2O3 using a sol-gel method. The photocatalysts were characterized by BET, UV-Vis diffuse reflectance spectroscopy and surface photovoltage spectroscopy (SPS), respectively. The result shows that 4%Pr doped Bi2O3 possesses the best photocatalytic activity under visible light.


2013 ◽  
Vol 331 ◽  
pp. 461-464
Author(s):  
Sheng Hui Yan ◽  
Yu Ting Zhang

t has been found that the photocatalytic activity of TiOB2B toward the decomposition of gaseous benzene in a batch reactor can be greatly improved by modifying TiOB2 Bin the presence of 3-(trimethoxysilyl) propylmethacrylate (MPS). The prepared photocatalyst (PMMA-TiOB2B) was characterized by FTIR, UV/Vis diffuse reflectance spectroscopy and XPS. PMMA-TiOB2 Bdemonstrates 2.3 times the photocatalytic activity of that of TiOB2B.


2020 ◽  
Vol 9 (3) ◽  
pp. 94-100
Author(s):  
Kim Nguyen Van ◽  
Nga Nguyen Thi Viet ◽  
Tuyen Vo Thi Thanh ◽  
Vien Vo

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.


Sign in / Sign up

Export Citation Format

Share Document