scholarly journals Photocatalytic Degradation of Phenol Using ImmobilizedTiO2Nanotube Photocatalysts

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Chung Leng Wong ◽  
Yong Nian Tan ◽  
Abdul Rahman Mohamed
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Silica Gel ◽  
Batch Reactor ◽  
Phenol Degradation ◽  
Reaction Medium ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Operating Cycles ◽  
Excellent Stability

TiO2nanotubes immobilized on silica gel were used in the photocatalytic degradation of phenol in a batch reactor. The highest rate of photocatalytic activity was observed when the ratios of TiO2nanotubes: silica gel: colloidal silica were 3 : 2 : 20. The optimal air flow rate for phenol degradation was 0.3 L/min while pH 3 was optimal for the reaction medium. Decreasing the initial phenol concentration led to an increase in phenol degradation efficiency due to more hydroxyl radicals being presented on the catalyst surface. Immobilized TiO2nanotubes showed higher photocatalytic activity than that of the pure TiO2which only achieved 87% degradation. Compared with pure TiO2, the immobilized TiO2nanotubes benefited from a larger specific surface area and a low recombination rate of photogenerated electron-hole pairs. After three operating cycles, the decrease in photocatalytic activity of the immobilized TiO2nanotubes was slight, indicating that the immobilized TiO2nanotubes have excellent stability and reusability.

Photocatalytic degradation of methylene blue from aqueous solutions using nanopillars-TiO2 thin films: Batch reactor studies

2018 ◽  
Vol 18 (3) ◽  
pp. 81-91 ◽  
Author(s):  
C. Lalhriatpuia
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Organic Carbon ◽  
Photocatalytic Degradation ◽  
Batch Reactor ◽  
Tio2 Thin Films ◽  
Initial Concentration ◽  
Bet Specific Surface Area ◽  
Interfering Ions

Nanopillars-TiO2 thin films was obtained on a borosilicate glass substrate with (S1) and without (S2) polyethylene glycol as template. The photocatalytic behaviour of S1 and S2 thin films was assessed inthe degradation of methylene blue (MB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the SEM, XRD, FTIR and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data confirmed that the TiO2 particles are in its anatase mineral phase. The SEM and AFM images indicated the catalyst is composed with nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of MB was well studied at wide range of physico-chemical parameters. The effect of solution pH (pH 4.0 to 10.0) and MB initial concentration (1.0 to 10.0 mg/L) was extensively studied and the effect of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of MB was demonstrated. The maximum percent removal of MB was observed at pH 8.0 beyond which it started decreasing and a low initial concentration of the pollutant highly favoured the photocatalytic degradation using thin films and the presence of several interfering ions diminished the photocatalytic activity of thin films to some extent. The overall photocatalytic activity was in the order: S2 > S1 > UV. The photocatalytic degradation of MB was followed the pseudo-first-order rate kinetics. The mineralization of MB was studied with total organic carbon measurement using the TOC (total organic carbon) analysis.

Use of Nanopillars-TiO2 Thin Films in the Photocatalytic Degradation of Bromophenol Blue from Aqueous Solution

2018 ◽  
Vol 6 (1) ◽  
pp. 22-30
Author(s):  
C. Lalhriatpuia ◽  
◽  
Thanhming liana ◽  
K. Vanlaldinpuia
Keyword(s):  
Thin Films ◽  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Batch Reactor ◽  
Bromophenol Blue ◽  
Tio2 Thin Films ◽  
Initial Concentration ◽  
Bet Specific Surface Area ◽  
Interfering Ions

The photocatalytic activity of Nanopillars-TiO2 thin films was assessed in the degradation of Bromophenol blue (BPB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the XRD, SEM and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data showed anatase phase of TiO2 particles with average particle size of 25.4 and 21.9 nm, for S1 and S2 catalysts respectively. The SEM and AFM images indicated the catalyst composed with Nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The average height of the pillars was found to be 180 and 40 nm respectively for the S1 and S2 catalyst. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of BPB using the UV light was studied at wide range of physico-chemical parametric studies to determine the mechanism of degradation as well as the practical applicability of the technique. The batch reactor operations were conducted at varied pH (pH 4.0 to 10.0), BPB initial concentration (1.0 to 20.0 mg/L) and presence of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of BPB. The maximum percent removal of BPB was observed at pH 6.0 and a low initial concentration of the pollutant highly favours the photocatalytic degradation using thin films. The presence of several interfering ions suppressed the photocatalytic activity of thin films to some extent. The time dependence photocatalytic degradation of BPB was demonstrated with the pseudo-first-order rate kinetics. Study was further extended with total organic carbon measurement using the TOC (Total Organic Carbon) analysis. This demonstrated an apparent mineralization of BPB from aqueous solutions.

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.

0D/3D-CdSe/Bi12TiO20 Pyramidal Heterostructure Photocatalysts for Enhanced Visible-Light Photocatalytic Activities

NANO ◽  
2017 ◽  
Vol 12 (06) ◽  
pp. 1750072 ◽  
Author(s):  
Tao Wang ◽  
Changchang Ma ◽  
Dan Wu ◽  
Xinlin Liu ◽  
Yang Liu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
High Stability ◽  
Photocatalytic Efficiency ◽  
Cdse Qds ◽  
Electron Hole ◽  
Adsorption Sites ◽  
Photocatalytic Activities ◽  
Visible Light Photocatalytic

In this paper, a novel heterostructure of 0D/3D-CdSe/Bi[Formula: see text]TiO[Formula: see text] pyramidal photocatalyst was synthesized and characterized. It exhibited significantly photocatalytic efficiency in photocatalytic degradation of the tetracycline than pure Bi[Formula: see text]TiO2 and CdSe and showed high stability. The enhanced photocatalytic activity might be attributed to the formation of heterostructure between CdSe QDs and 3D Bi[Formula: see text]TiO[Formula: see text], in which CdSe QDs served as electron trapper to improve the separation of photodegradation electron–hole pairs, and provided a number of active adsorption sites for the photogenerated of pollutants. The photocatalytic mechanism of 0D/3D-CdSe/Bi[Formula: see text]TiO[Formula: see text] pyramidal heterostructure was also proposed.

Hierarchical Z-scheme 1D/2D architecture with TiO2 nanowires decorated by MnO2 nanosheets for efficient adsorption and full spectrum photocatalytic degradation of organic pollutants

2020 ◽  
Vol 10 (11) ◽  
pp. 3603-3612
Author(s):  
Jiejing Zhang ◽  
Yajie Hu ◽  
Hong Zheng ◽  
Pengyi Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Organic Pollutants ◽  
Organic Pollutant ◽  
Pollutant Removal ◽  
Tio2 Nanowires ◽  
Full Spectrum ◽  
Mno2 Nanosheets ◽  
Excellent Stability

A novel hierarchical 1D/2D TiO2/MnO2 composite shows superior adsorption, full spectrum photocatalytic activity and excellent stability for organic pollutant removal.

Synthesis of TiO2-Reduced Graphene Oxide Nanocomposites Offering Highly Enhanced Photocatalytic Activity

2019 ◽  
Vol 19 (11) ◽  
pp. 7089-7096 ◽  
Author(s):  
Wufa Li ◽  
Xiaohong Yang ◽  
Haitao Fu ◽  
Xizhong An ◽  
Haiyang Zhao
Keyword(s):  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Environmental Remediation ◽  
Hydrothermal Reaction ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Reduced Graphene ◽  
Vis Spectroscopy ◽  
Hole Recombination

Photogenerated electron–hole recombination significantly restricts the catalytic efficiency of titanium dioxide (TiO2). Various approaches have been developed to overcome this problem, yet it remains challenging. Recently, graphene modification of TiO2 has been considered as an effective alternative to prevent electron–hole recombination and consequently enhance the photocatalytic performance of TiO2. This study reports an efficient but simple hydrothermal method utilizing titanium (IV) butoxide (TBT) and graphene oxide (GO) to prepare TiO2-reduced graphene oxide (RGO) nanocomposites under mild reaction conditions. This method possesses several advantageous features, including no requirement of high temperature for TiO2 crystallization and a one-step hydrothermal reaction for mild reduction of GO without a reducing agent, which consequently makes the production of TiO2-RGO nanocomposites possible in a green and an efficient synthetic route. Moreover, the as-synthesized nanocomposites were characterized by numerous advanced techniques (SEM, TEM, BET, XRD, XPS, and UV-vis spectroscopy). In particular, the photocatalytic activities of the synthesized TiO2-RGO nanocomposites were evaluated by degrading the organic molecules (methylene blue, MB), and it was found that the photocatalytic activity of TiO2-RGO nanocomposites is ~4.5 times higher compared to that of pure TiO2. These findings would be useful for designing reduced graphene oxide-metal oxide hybrids with desirable functionalities in various applications for energy storage devices and environmental remediation.

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.

Synthesis of Er-doped Bi2WO6 and enhancement in photocatalytic activity induced by visible light

RSC Advances ◽  
2015 ◽  
Vol 5 (115) ◽  
pp. 94887-94894 ◽  
Author(s):  
Meng Wang ◽  
Ziyu Qiao ◽  
Minghao Fang ◽  
Zhaohui Huang ◽  
Yan'gai Liu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Er Doped

1.5% Bi2WO6:Er3+ exhibited highest photocatalytic activity as the separation efficiency of the photogenerated electron–hole pairs is enhanced.

scholarly journals Enhancement of photocatalytic activity of TiO2 nanoparticles by silver doping: photodeposition versus liquid impregnation methods

2013 ◽  
Vol 10 (1) ◽  
pp. 1-7 ◽  
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Tio2 Nanoparticles ◽  
Model Compound ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Doped Tio2 ◽  
Liquid Impregnation ◽  
Positive Effect

Silver doped TiO2 nanoparticles have been prepared by liquid impregnation (LI) and photodeposition (PD) methods and characterized by surface analytical methods such as scanning electron micrographs (SEM) and X-ray diffraction (XRD). The photocatalytic activity of silver doped TiO2 was tested by photocatalytic degradation of C.I. Acid Red 88 (AR88) as a model compound from monoazo textile dyes. Results show silver doped TiO2 is more efficient than undoped TiO2 at photocatalytic degradation of AR88. The positive effect of silver on the photoactivity of TiO2 at degradation of AR88 may be explained by its ability to trap electrons. This process reduces the recombination of light generated electron-hole pairs at TiO2 surface. Silver content has an optimum value 2% in LI and 0.5% in PD methods for achieving high photocatalytic activity. The AR88 decomposition with Ag-photodeposited method was much higher than that of deposited with LI method.

scholarly journals Photocatalytic Adsorption Synergistic Degradation of Tetracycline by Z-scheme Bi2WO6/ZIF-8

2021 ◽  
Author(s):  
Xiaojun Dai ◽  
sheng feng ◽  
Wei Wu ◽  
Yun Zhou ◽  
Zhiwei Ye ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Photogenerated Electron ◽  
Utilization Efficiency ◽  
Electron Hole ◽  
Effects Of Ph ◽  
Growth Method ◽  
Synergistic Degradation ◽  
First Time

Abstract In this paper, in order to improved the photocatalytic activity of Bi2WO6, Bi2WO6 and ZIF-8 were successfully combined by in-situ growth method for the first time. The addition of ZIF-8 effectively inhibited the recombination of photogenerated electron hole pairs and further improved the electron utilization efficiency, and superoxide anion was introduced to greatly improve the photocatalytic activity. The performance of Bi2WO6/ZIF-8 in the photodegradation of tetracycline (TC) was studied under different conditions of proportions of ZIF-8, dosage of catalyst and concentration of TC. The results indicated that B/Z/5/1 (10mg) had the best photocatalytic activity, and 97.8% of TC (20mg/L) could be degraded in 80 minutes under UV light, the rate constant (k) for TC degradation was almost 3 times that of Bi2WO6. The effects of pH, HA and inorganic anions on the degradation of TC were studied in simulated real water. Further, B/Z/5/1 could be reutilized up to five cycles without reduction of efficiency and catalysis performance. Therefore, Bi2WO6/ZIF-8 heterojunction composite material can be utilized as an efficient photocatalyst for remediation of environmental pollution.

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