scholarly journals Influence of Post-Treatment Operations on Structural Properties and Photocatalytic Activity of Octahedral Anatase Titania Particles Prepared by an Ultrasonication-Hydrothermal Reaction

Molecules ◽  
2014 ◽  
Vol 19 (12) ◽  
pp. 19573-19587 ◽  
Author(s):  
Zhishun Wei ◽  
Ewa Kowalska ◽  
Bunsho Ohtani
2010 ◽  
Vol 25 (6) ◽  
pp. 1096-1104 ◽  
Author(s):  
Jum Suk Jang ◽  
Eun Sun Kim ◽  
Hyun Gyu Kim ◽  
Sang Min Ji ◽  
Youngkwon Kim ◽  
...  

Nitrogen-doped titania with a unique two-level hierarchical structure and visible light photocatalytic activity is reported. Thus, nitrogen-doped titanium oxide microrods decorated with N-doped titanium oxide nanosheets were synthesized by a hydrothermal reaction in NH4OH and postcalcination. During the calcination, the in situ incorporation of nitrogen atoms of ammonium ion into titania lattice was accompanied by the structural evolution from titanate to anatase titania. The morphological and structural evolution was monitored by scanning electron microscopy (SEM), x-ray diffraction (XRD), thermogravimetric analysis/differential thermal analysis (TGA/DTA), Raman, Fourier transform infrared (FTIR), x-ray absorption near edge structure (XANES), x-ray photoelectron spectroscopy (XPS), and adsorption isotherms. The N-doping brought visible light absorption, and the material exhibited high photocatalytic activity in the decomposition of Orange II under visible light irradiation (λ ≥ 400 nm), especially when it was loaded with 1 wt% Pt as a cocatalyst.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wenjie Wang ◽  
Mengran Zhang ◽  
Binxia Zhao ◽  
Linxue Liu ◽  
Ruixuan Han ◽  
...  

Purpose The purpose of this paper is to improve the degradation efficiency of Rhodamine B (RhB) by new photocatalytic materials. Design/methodology/approach Binary Z-scheme g-C3N4/Bi2WO6 photocatalytic material was synthesized by the one-step hydrothermal reaction. The construction of Z-scheme heterojunction led to the rapid separation of photogenerated electrons and holes, which would degrade RhB into small molecular substances to achieve the purpose of degradation. Findings It was found that Bi2WO6/25%g-C3N4 displayed the highest photocatalytic activity, which was about 1.44 and 1.34 times higher than that of pure Bi2WO6 and g-C3N4, respectively. According to the trapping experiments, the superoxide radical (·O2−) was the major active species of the RhB decomposition in Bi2WO6/g-C3N4 catalysts. Originality/value The successful synthesis of Z-scheme Bi2WO6/g-C3N4 provides new ideas and references for the design of catalysts with high photocatalytic activity, which should have wide applications in the future.


2020 ◽  
Vol 44 (5) ◽  
pp. 1942-1952 ◽  
Author(s):  
Qiong Sun ◽  
Kaijing Li ◽  
Songhao Wu ◽  
Bing Han ◽  
Lina Sui ◽  
...  

A neutral, facile and universal hydrothermal post-treatment of TiO2 was developed to significantly improve its photocatalytic activity.


Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2763
Author(s):  
Zuzanna Bielan ◽  
Szymon Dudziak ◽  
Agnieszka Sulowska ◽  
Daniel Pelczarski ◽  
Jacek Ryl ◽  
...  

Among various methods of improving visible light activity of titanium(IV) oxide, the formation of defects and vacancies (both oxygen and titanium) in the crystal structure of TiO2 is an easy and relatively cheap alternative to improve the photocatalytic activity. In the presented work, visible light active defective TiO2 was obtained by the hydrothermal reaction in the presence of three different oxidizing agents: HIO3, H2O2, and HNO3. Further study on the effect of used oxidant and calcination temperature on the physicochemical and photocatalytic properties of defective TiO2 was performed. Obtained nanostructures were characterized by X-ray diffractometry (XRD), specific surface area (BET) measurements, UV-Vis diffuse reflectance spectroscopy (DR-UV/Vis), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR) spectroscopy. Degradation of phenol as a model pollutant was measured in the range of UV-Vis and Vis irradiation, demonstrating a significant increase of photocatalytic activity of defective TiO2 samples above 420 nm, comparing to non-defected TiO2. Correlation of EPR, UV-Vis, PL, and photodegradation results revealed that the optimum concentration of HIO3 to achieve high photocatalytic activity was in the range of 20–50 mol%. Above that dosage, titanium vacancies amount is too high, and the obtained materials’ photoactivity was significantly decreased. Studies on the photocatalytic mechanism using defective TiO2 have also shown that •O2− radical is mainly responsible for pollutant degradation.


CrystEngComm ◽  
2020 ◽  
Vol 22 (31) ◽  
pp. 5245-5254 ◽  
Author(s):  
Qian Zhang ◽  
Xiaoru Zhao ◽  
Libing Duan ◽  
Hao Shen ◽  
Ruidi Liu ◽  
...  

We develop a novel method to prepare an oxygen-deficient ZnO@C core/shell based on a traditional hydrothermal reaction, and investigate the role of the carbon core and oxygen vacancies in the photocatalytic activity and photoluminescence processes.


2021 ◽  
Vol 149 ◽  
pp. 109762
Author(s):  
Hanggara Sudrajat ◽  
Sri Hartuti ◽  
Sandhya Babel ◽  
Truong Khang Nguyen ◽  
Hien Duy Tong

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