Preparation of graphene-TiO2 nanocomposite films and its photocatalytic performances on degradation of Rhodamine B

2018 ◽  
Vol 47 (1) ◽  
pp. 79-85
Author(s):  
Pei Qin ◽  
Guobin Yi ◽  
Xihong Zu ◽  
Huan Wang ◽  
Hongsheng Luo ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Performance ◽  
Separation Efficiency ◽  
Diffuse Reflectance Spectrum ◽  
Photogenerated Electron ◽  
Nanocomposite Films ◽  
Nanorod Arrays ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Content Type

Purpose The aim of this paper is to synthesize graphene-modified titanium dioxide (GR-TiO2) nanorod arrays nanocomposite films, so that these can enhance the photocatalytic properties of titanium dioxide and overcome the problem of difficult separation and recovery of photocatalysts. Design/methodology/approach The GR-TiO2 nanocomposite films were synthesized via hydrothermal method and spin-coating. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet–visible (UV-Vis) diffuse reflectance spectrum and Raman spectrum. The photocatalytic performance of the GR-TiO2 nanocomposite films for degrading Rhodamin B under ultraviolet (UV) was studied by a UV-Vis spectrophotometer. The photocatalytic enhancement mechanism of graphene was studied by photoelectrochemical analysis. Findings The introduction of graphene expanded the range of the optical response of TiO2 nanorod arrays, improving the separation efficiency of the photogenerated electron-hole pairs, and thus dramatically increasing its photocatalytic performance. Research limitations/implications A simple and novel way for synthesizing GR-TiO2 nanocomposite films has enhanced the photocatalytic performance of TiO2. Originality/value The photocatalyst synthesized is easy to separate and recycle in the process of photocatalytic reaction, so it is possible to achieve industrialization.

scholarly journals Construction of Ag3PO4/SnO2 Heterojunction on Carbon Cloth with Enhanced Visible Light Photocatalytic Degradation

2020 ◽  
Vol 10 (9) ◽  
pp. 3238
Author(s):  
Min Liu ◽  
Guangxin Wang ◽  
Panpan Xu ◽  
Yanfeng Zhu ◽  
Wuhui Li
Keyword(s):  
Visible Light ◽  
Photocatalytic Performance ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Carbon Cloth ◽  
Electron Hole ◽  
Step Process ◽  
Photogenerated Electrons ◽  
Rapid Transfer ◽  
Visible Light Photocatalytic

In this study, the Ag3PO4/SnO2 heterojunction on carbon cloth (Ag3PO4/SnO2/CC) was successfully fabricated via a facile two-step process. The results showed that the Ag3PO4/SnO2/CC heterojunction exhibited a remarkable photocatalytic performance for the degradation of Rhodamine B (RhB) and methylene blue (MB), under visible light irradiation. The calculated k values for the degradation of RhB and MB over Ag3PO4/SnO2/CC are 0.04716 min−1 and 0.04916 min−1, which are higher than those calculated for the reactions over Ag3PO4/SnO2, Ag3PO4/CC and SnO2/CC, respectively. The enhanced photocatalytic activity could mainly be attributed to the improved separation efficiency of photogenerated electron-hole pairs, after the formation of the Ag3PO4/SnO2/CC heterojunction. Moreover, carbon cloth with a large specific surface area and excellent conductivity was used as the substrate, which helped to increase the contact area of dye solution with photocatalysts and the rapid transfer of photogenerated electrons. Notably, when compared with the powder catalyst, the catalysts supported on carbon cloth are easier to quickly recycle from the pollutant solution, thereby reducing the probability of recontamination.

scholarly journals Titanium Dioxide: From Engineering to Applications

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 191 ◽  
Author(s):  
Xiaolan Kang ◽  
Sihang Liu ◽  
Zideng Dai ◽  
Yunping He ◽  
Xuezhi Song ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Environmental Pollutants ◽  
Photogenerated Electron ◽  
Wide Bandgap ◽  
Electron Hole ◽  
Crystal Facet ◽  
Tio2 Lattice ◽  
Tio2 Nanomaterials

Titanium dioxide (TiO2) nanomaterials have garnered extensive scientific interest since 1972 and have been widely used in many areas, such as sustainable energy generation and the removal of environmental pollutants. Although TiO2 possesses the desired performance in utilizing ultraviolet light, its overall solar activity is still very limited because of a wide bandgap (3.0–3.2 eV) that cannot make use of visible light or light of longer wavelength. This phenomenon is a deficiency for TiO2 with respect to its potential application in visible light photocatalysis and photoelectrochemical devices, as well as photovoltaics and sensors. The high overpotential, sluggish migration, and rapid recombination of photogenerated electron/hole pairs are crucial factors that restrict further application of TiO2. Recently, a broad range of research efforts has been devoted to enhancing the optical and electrical properties of TiO2, resulting in improved photocatalytic activity. This review mainly outlines state-of-the-art modification strategies in optimizing the photocatalytic performance of TiO2, including the introduction of intrinsic defects and foreign species into the TiO2 lattice, morphology and crystal facet control, and the development of unique mesocrystal structures. The band structures, electronic properties, and chemical features of the modified TiO2 nanomaterials are clarified in detail along with details regarding their photocatalytic performance and various applications.

Novel RGO and Concave Cube Cu2O Co-Modified BiVO4 Nanosheets with Enhanced Photocatalytic and Surface Adsorption Performances of Tetracycline

NANO ◽  
2019 ◽  
Vol 14 (02) ◽  
pp. 1950015 ◽  
Author(s):  
Xin Gao ◽  
Changchang Ma ◽  
Wei Ma ◽  
Rongru Chen ◽  
Yang Liu ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Photocatalytic Performance ◽  
Separation Efficiency ◽  
Narrow Band ◽  
Photogenerated Electron ◽  
High Adsorption ◽  
Electron Hole ◽  
Composite Photocatalyst ◽  
Radical Trapping ◽  
Spin Resonance

A novel ternary Cu2O/BiVO4/RGO photocatalyst is successfully constructed by hydrothermal and evaporation-induced method, and it exhibits superior photocatalytic performance for degradation tetracycline (TC). Meanwhile, the visible light absorption range of composite photocatalyst is effectively broadened by the formation of heterojunction with narrow band gap semiconductor Cu2O. And the separation efficiency of the photogenerated electron–hole pairs is significantly enhanced by the synergistic effect of Cu2O and RGO. More importantly, the adsorption of TC by ternary Cu2O/BiVO4/RGO possesses high adsorption capacity, which is 23.73 times higher than that of pure BiVO4. Additionally, the possible reaction mechanism is clearly revealed by radical trapping experiment, electron spin-resonance (ESR) spectroscopy. This work provides a new insight to design a photocatalyst with excellent adsorption to remove organic contaminants in water.

scholarly journals Preparation and Photocatalytic Performance for Degradation of Rhodamine B of AgPt/Bi4Ti3O12 Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2206
Author(s):  
Gaoqian Yuan ◽  
Gen Zhang ◽  
Kezhuo Li ◽  
Faliang Li ◽  
Yunbo Cao ◽  
...  
Keyword(s):  
Visible Light ◽  
Noble Metal ◽  
Rhodamine B ◽  
Photocatalytic Performance ◽  
Bimetallic Nanoparticles ◽  
Resonance Effect ◽  
Visible Region ◽  
Photogenerated Electron ◽  
Pt Nanoparticles ◽  
Electron Hole

Loading a noble metal on Bi4Ti3O12 could enable the formation of the Schottky barrier at the interface between the former and the latter, which causes electrons to be trapped and inhibits the recombination of photoelectrons and photoholes. In this paper, AgPt/Bi4Ti3O12 composite photocatalysts were prepared using the photoreduction method, and the effects of the type and content of noble metal on the photocatalytic performance of the catalysts were investigated. The photocatalytic degradation of rhodamine B (RhB) showed that the loading of AgPt bimetallic nanoparticles significantly improved the catalytic performance of Bi4Ti3O12. When 0.10 wt% noble metal was loaded, the degradation rate for RhB of Ag0.7Pt0.3/Bi4Ti3O12 was 0.027 min−1, which was respectively about 2, 1.7 and 3.7 times as that of Ag/Bi4Ti3O12, Pt/Bi3Ti4O12 and Bi4Ti3O12. The reasons may be attributed as follows: (i) the utilization of visible light was enhanced due to the surface plasmon resonance effect of Ag and Pt in the visible region; (ii) Ag nanoparticles mainly acted as electron acceptors to restrain the recombination of photogenerated electron-hole pairs under visible light irradiation; and (iii) Pt nanoparticles acted as electron cocatalysts to further suppress the recombination of photogenerated electron-hole pairs. The photocatalytic performance of Ag0.7Pt0.3/Bi4Ti3O12 was superior to that of Ag/Bi4Ti3O12 and Pt/Bi3Ti4O12 owing to the synergistic effect between Ag and Pt nanoparticles.

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.

Synthesis and Photocatalytic Properties of the Bi2MoO6 and Bi2WO6 Photocatalysts

2018 ◽  
Vol 768 ◽  
pp. 218-223
Author(s):  
Juan Xia ◽  
Lin Zhang ◽  
Qi Wang
Keyword(s):  
Light Absorption ◽  
Hydrothermal Reaction ◽  
Organic Dyes ◽  
High Surface ◽  
Diffuse Reflectance Spectrum ◽  
High Surface Area ◽  
Photocatalytic Properties ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
One Pot

Two different Bi-based semiconductor photocatalysts Bi2MoO6 and Bi2WO6 were synthesized by a simple one-pot hydrothermal reaction at 453 K for 10 h. The properties of the photocatalysts, including structures, morphology, light-absorption band and photoluminescence, etc were characterized by X-ray diffraction, scanning electron microscopy, UV-Vis diffuse reflectance spectrum and fluorescence spectrum. Further, their photocatalytic properties were compared by the degradation of two different organic dyes: Rhodamine B and methylene blue. It is important to note that the Bi2WO6 nanoplate structure exhibited better photocatalytic activity than the Bi2MoO6 nanowires aggregates due to its high surface area, higher light absorption and lower recombination of electron-hole pairs.

scholarly journals Fabrication of a Cu2O-Au-TiO2 Heterostructure with Improved Photocatalytic Performance for the Abatement of Hazardous Toluene and α-Pinene Vapors

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1434
Author(s):  
Joon Yeob Lee ◽  
Jeong-Hak Choi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photocatalytic Oxidation ◽  
Separation Efficiency ◽  
Diffuse Reflectance Spectrum ◽  
Visible Region ◽  
Pure Tio2 ◽  
Great Promise ◽  
Light Sources ◽  
Electron Hole ◽  
X Ray

In the current research, a Cu2O-Au-TiO2 heterostructure was fabricated via a step-wise photodeposition route to determine its possible application in the photocatalytic oxidation of hazardous vapors. The results of electron microscopy and X-ray photoelectron spectroscopy confirm the successful fabrication of the Cu2O-Au-TiO2 heterostructure. Strong absorption in the visible region, along with a slight red-shift in the absorption edge, was observed in the UV–vis diffuse reflectance spectrum of Cu2O-Au-TiO2 composite, which implies that the composite can generate a greater number of photoexcited charges necessary for photocatalytic reaction. Toluene and α-pinene, as common gas contaminants in the indoor atmosphere, were employed to assess the photooxidation efficiency of the Cu2O-Au-TiO2 composite. Importantly, photocatalytic activity results indicate that the Cu2O-Au-TiO2 composite showed excellent photodegradation performance compared to pure TiO2 and Cu2O-TiO2 and Au-TiO2, where photocatalytic efficiency was approximately 92.9% and 99.9% for toluene and α-pinene, respectively, under standard daylight illumination. The increased light-harvesting capacity and boosted separation efficiency of electron-hole pairs were mainly accountable for improved degradation performance of the Cu2O-Au-TiO2 composite. In addition, the degradation efficiencies for toluene and α-pinene by the Cu2O-Au-TiO2 composite were also examined under three different light sources: 0.32 W white, blue and violet LEDs. The findings of this work suggested a great promise of effective photooxidation of gas pollutants by the Cu2O-Au-TiO2 composite.

The Transfer Direction of Photogenerated Electrons in BaTiO3/TiO2 and CaTiO3/TiO2

2018 ◽  
Vol 71 (12) ◽  
pp. 965
Author(s):  
Lingfeng Ruan ◽  
Rongying Jiang ◽  
Jing Liu ◽  
Song Liu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photogenerated Electron ◽  
Tio2 Films ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Photogenerated Electrons ◽  
Microscopy Techniques ◽  
Transfer Direction ◽  
Physical Principles

BaTiO3/TiO2 and CaTiO3/TiO2 bilayer-type photocatalyst films have been prepared and characterised by X-ray diffraction, Raman, X-ray photoelectron spectroscopy, UV-vis, and scanning electron microscopy techniques. The photodeposition of silver was done to confirm the reduction positions of the titanate/TiO2 films. Silver deposited preferentially on the side of TiO2 for BaTiO3/TiO2 whereas on the side of CaTiO3 for CaTiO3/TiO2. These results imply that the direction of photogenerated electron transfer is coincident with the semiconductor physical principles. Upon exposure to light, electron–hole pairs are generated and subsequently separated by an internal electrostatic field in the titanate–TiO2 heterojunction.

NiFe-LDH@ZnO@NF composite for photo-degradation of Rhodamine B dye

MRS Advances ◽  
2019 ◽  
Vol 4 (33-34) ◽  
pp. 1887-1893
Author(s):  
Jun Wu ◽  
Yonghui Gong ◽  
Qiang Fu ◽  
Chunxu Pan
Keyword(s):  
Rhodamine B ◽  
Photocatalytic Performance ◽  
Nickel Foam ◽  
Photogenerated Electron ◽  
Chemical Compositions ◽  
Photocatalytic Efficiency ◽  
Electron Hole ◽  
Photo Degradation ◽  
Potential Applications ◽  
Rhodamine B Dye

ABSTRACTIn this paper, a novel NiFe-LDH@ZnO composite was prepared by using a facile two-step process upon nickel foam (NF) substrate. The morphologies and chemical compositions of the samples were characterized by SEM, EDS, XRD and XPS. Photocatalytic degradation of Rhodamine B dye was tested with the samples NiFe-LDH@ZnO@NF, ZnO@NF and NiFe-LDH under the same conditions. The experimental results revealed that the NiFe-LDH@ZnO@NF composite exhibited excellent photocatalytic performance, i.e., 1.4 and 2.5 times higher than that of pure ZnO and NiFe-LDH, respectively. The reason was that the NiFe-LDH@ZnO@NF composite provided a possibility to effectively inhibit the recombination of the photogenerated electron-hole pairs, and therefore enhanced the photocatalytic efficiency. This composite is expected to have potential applications in wastewater treatment field.

Fabrication, characterization and photocatalytic activity of g-C3N4 coupled with FeVO4 nanorods

RSC Advances ◽  
2015 ◽  
Vol 5 (35) ◽  
pp. 27933-27939 ◽  
Author(s):  
Qingyan Nong ◽  
Min Cui ◽  
Hongjun Lin ◽  
Leihong Zhao ◽  
Yiming He
Keyword(s):  
Photocatalytic Activity ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Electron Hole

The coupling of FeVO4 nanorods with g-C3N4 promotes the separation efficiency of photogenerated electron–hole pairs, and subsequently enhances its photocatalytic activity in rhodamine photodegradation.

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