Convenient synthesis of TiO2 nanowires with anatase phase for high photocatalytic activity

2020 ◽  
Vol 10 (4) ◽  
pp. 537-542
Author(s):  
Fei Tian ◽  
Gen Zhu ◽  
Kexin Shen ◽  
Chunju Li ◽  
Haitao Li ◽  
...  

Organic pollutants pose a serious threat to human health, and so their control by photocatalytic techniques has become an important field. There is an urgent need to devise convenient syntheses of effective photocatalysts for the degradation of contaminants. Here, high-performance anatase TiO2 nanowires have been obtained through a hydrothermal method followed by calcination at different temperatures in Ar. The products have been characterized by SEM, XRD, FTIR, and UV/Vis DRS measurements. The photocatalytic performances of the as-prepared catalysts in the degradation of rhodamine 6G (R6G) have been evaluated. The experimental results revealed that as-prepared TiO2 nanowires calcined at 600 °C (TNWs-600) exhibited the highest degree of R6G degradation (96%) under simulated solar irradiation. This could be attributed to their stable anatase phase with good photocatalytic activity, the excellent light absorption ability of which favors excitation. Overall, the fabricated TNWs-600 constitute a promising candidate material for photocatalytic applications in the removal of environmental pollutants.

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 589
Author(s):  
Sivagowri Shanmugaratnam ◽  
Balaranjan Selvaratnam ◽  
Aravind Baride ◽  
Ranjit Koodali ◽  
Punniamoorthy Ravirajan ◽  
...  

Earth–abundant transition metal chalcogenide materials are of great research interest for energy production and environmental remediation, as they exhibit better photocatalytic activity due to their suitable electronic and optical properties. This study focuses on the photocatalytic activity of flower-like SnS2 nanoparticles (composed of nanosheet subunits) embedded in TiO2 synthesized by a facile hydrothermal method. The materials were characterized using different techniques, and their photocatalytic activity was assessed for hydrogen evolution reaction and the degradation of methylene blue. Among the catalysts studied, 10 wt. % of SnS2 loaded TiO2 nanocomposite shows an optimum hydrogen evolution rate of 195.55 µmolg−1, whereas 15 wt. % loading of SnS2 on TiO2 exhibits better performance against the degradation of methylene blue (MB) with the rate constant of 4.415 × 10−4 s−1 under solar simulated irradiation. The improved performance of these materials can be attributed to the effective photo-induced charge transfer and reduced recombination, which make these nanocomposite materials promising candidates for the development of high-performance next-generation photocatalyst materials. Further, scavenging experiments were carried out to confirm the reactive oxygen species (ROS) involved in the photocatalytic degradation. It can be observed that there was a 78% reduction in the rate of degradation when IPA was used as the scavenger, whereas around 95% reduction was attained while N2 was used as the scavenger. Notably, very low degradation (<5%) was attained when the dye alone was directly under solar irradiation. These results further validate that the •OH radical and the superoxide radicals can be acknowledged for the degradation mechanism of MB, and the enhancement of degradation efficiency may be due to the combined effect of in situ dye sensitization during the catalysis and the impregnation of low bandgap materials on TiO2.


NANO ◽  
2016 ◽  
Vol 11 (05) ◽  
pp. 1650054 ◽  
Author(s):  
Bin Zeng ◽  
Yang Yin

CuS hexagonal nanosheet/graphene was fabricated by a facile one-pot microwave-thermal method. The samples possess excellent photocatalytic activity for degradation of organic pollutant under visible light. The high photocatalytic activity was attributed to the deposition of CuS hexagonal nanosheet onto graphene. CuS nanosheet serves as a transporter which efficiently inhibits the recombination of the photo-induced charge carriers in the nanocomposites. The developed method demonstrates a facile approach towards the synthesis of two-dimensional semiconductor-graphene nanocomposites with excellent photocatalytic performance under visible light.


2018 ◽  
Vol 54 (4B) ◽  
pp. 42
Author(s):  
Trinh Duy Nguyen

Flower-like Bi2WO6 were successfully synthesized using the solvothermal method at different temperatures and characterized by XRD, FE-SEM, and DRS. We also investigated the photocatalytic activity of Bi2WO6 for the decomposition of rhodamine B under visible light irradiation. From XRD and SEM results, the reaction temperature has significant effects on the morphologies of the samples. From DRS results, Bi2WO6 samples displayed the absorption spectrum up to the visible region and then they showed the high photocatalytic activity under visible light irradiation, as a comparison with TiO2-P25.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
C. R. García ◽  
L. A. Diaz-Torres ◽  
J. Oliva ◽  
M. T. Romero ◽  
P. Salas

Blue phosphorescent strontium aluminosilicate powders were prepared by combustion synthesis route and a postannealing treatments at different temperatures. X-ray diffraction analysis showed that phosphors are composed of two main hexagonal phases: SrAl2O4and Sr3Al32O51. The morphology of the phosphors changed from micrograins (1000°C) to a mixture of bars and hexagons (1200°C) and finally to only hexagons (1300°C) as the annealing temperature is increased. Photoluminescence spectra showed a strong blue-green phosphorescent emission centered atλem=455 nm, which is associated with4f65d1→4f6  (8S7/2)transition of the Eu2+. The sample annealed at 1200°C presents the highest luminance value (40 Cd/m2) with CIE coordinates (0.1589, 0.1972). Also, the photocatalytic degradation of methylene blue (MB) under UV light (at 365 nm) was monitored. Samples annealed at 1000°C and 1300°C presented the highest percentage of degradation (32% and 38.5%, resp.) after 360 min. In the case of photocatalytic activity under solar irradiation, the samples annealed at 1000°C, 1150°C, and 1200°C produced total degradation of MB after only 300 min. Hence, the results obtained with solar photocatalysis suggest that our powders could be useful for water cleaning in water treatment plants.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Yinzhen Wang ◽  
Ning Li ◽  
Pingping Duan ◽  
Xuwei Sun ◽  
Benli Chu ◽  
...  

β-Ga2O3nanorods are prepared by hydrothermal method and characterized by X-ray diffraction, high-resolution transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence spectra. The results reveal that high crystallinity, monoclinic phase ofβ-Ga2O3nanorods were prepared with a diameter of about 60 nm and length of 500 nm. Photoluminescence study indicates that theβ-Ga2O3nanorods exhibit a broad blue light emission at room temperature. Theβ-Ga2O3nanorods displayed high photocatalytic activity under simulated solar irradiation; after 2 h irradiation, over 95% of methylene blue solution and over 90% of methyl orange solution were decolorized. Since this process does not require additional hydrogen peroxide and uses solar light, it can be developed as an economically feasible and environmentally friendly method to treat dye effluent.


2010 ◽  
Vol 658 ◽  
pp. 483-486
Author(s):  
Jong Oh Kim ◽  
Won Youl Choi

An anodized TiO2 membrane has enhanced photocatalytic properties of anatase phase and small crystal size. From the photocatalytic results, the prepared anodized nano-structured TiO2 membrane had an effective organics decomposition capacity and high water permeability. This anodization method enabled the prepared nano-structured TiO2 membrane to have high photocatalytic activity and desired pore structure.


NANO ◽  
2016 ◽  
Vol 11 (06) ◽  
pp. 1650068 ◽  
Author(s):  
Jimin Du ◽  
Huiming Wang ◽  
Huijuan Chen ◽  
Menghe Yang ◽  
Xiaoling Lu ◽  
...  

Black Porous Zr-doped TiO2 monoliths were successfully synthesized by a combined route including sol–gel method with polystyrene spheres as template followed by calcination at high temperature in the presence of oxygen. As-synthesized samples were then treated in hydrogen atmosphere at 500[Formula: see text]C for 6[Formula: see text]h to obtain black Porous Zr-doped TiO2 monoliths. This as-synthesized black porous Zr-doped TiO2 composite showed relatively narrow bandgap compared to the pure anatase phase of TiO2, which may have its origin from the contributions from the Zr impurity and oxygen vacancies. The photocatalytic activity of the black porous Zr-doped TiO2 monolith was examined by carrying out the dye degradation on Rhodamine B under visible irradiation. Our experimental results indicate that black porous 0.9% Zr-doped TiO2 sample exhibits high photocatalytic activity with the photodecomposition of 95.25% under visible irradiation for 120[Formula: see text]min.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Kanji Saito ◽  
Shota Orikasa ◽  
Yusuke Asakura ◽  
Yusuke Ide ◽  
Yoshiyuki Sugahara ◽  
...  

A unique structural transformation of a lepidocrocite-type layered titanate, K0.8Ti1.73Li0.27O4, into a rutile-type TiO2 has recently been realized via dilute HCl treatment and subsequent drying at room temperature for producing rutile-nanoparticle-decorated protonated layered titanate exhibiting highly efficient photocatalytic activity. Herein, the authors report synthesis of a lepidocrocite-type layered cesium titanate with nominal compositions of C s 0.7 T i 1.825 ‐ x / 2 N i x □ 0.175 ‐ x / 2 O 4 ( x = 0 , 0.05, 0.1, and 0.35) through solid-state reactions of Cs2CO3, TiO2, and Ni(CH3COO)2·4H2O at different temperatures (600 or 800°C), followed by treatment with dilute HCl and subsequent drying to produce a Ni-doped protonated layered titanate/TiO2 composite. C s 0.7 T i 1.825 ‐ x / 2 N i x □ 0.175 ‐ x / 2 O 4 with an optimized Ni content obtained at a lower temperature was converted into a Ni-doped protonated layered titanate/TiO2 composite to exhibit high photocatalytic activity for NO x decomposition reactions.


NANO ◽  
2016 ◽  
Vol 11 (08) ◽  
pp. 1650087 ◽  
Author(s):  
Hui Meng ◽  
Tingting Wang ◽  
Hongbin Chen ◽  
Yizhu Liu ◽  
Xiang Yu ◽  
...  

BiOCl/SnS2 core-shell heterojunction is prepared by a facile and economic hydrothermal method. The obtained BiOCl/SnS2 heterojunction displays high photocatalytic activity in the degradation of Rhodamine B (RhB). The high performance is explained by the fast separation of the photoinduced electron–hole pairs promoted by the heterojunction. The cycle life of the heterojunction is also improved compared with individual BiOCl or SnS2.


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