Impact of Al doping on a hydrothermally synthesized β-Ga2O3 nanostructure for photocatalysis applications

RSC Advances ◽  
2021 ◽  
Vol 11 (13) ◽  
pp. 7338-7346
Author(s):  
Sunjae Kim ◽  
Heejoong Ryou ◽  
In Gyu Lee ◽  
Myunghun Shin ◽  
Byung Jin Cho ◽  
...  

The photocatalytic activity is correlated with different parameters affecting the photocatalytic reactions; redox potential (RP), surface area (SA), crystal defect (CD), oxygen defect (OD), and grain-boundary induced defect (GD).

2003 ◽  
Vol 5 (3) ◽  
pp. 159-166 ◽  
Author(s):  
Evgeny I. Kapinus ◽  
Tatyana A. Khalyavka ◽  
Valentina V. Shimanovskaya ◽  
Tatyana I. Viktorova ◽  
Vladimir V. Strelko

Dispersed optically pure anatase, rutile and two-phase samples of titanium dioxide were prepared using a sol-gel technique. In particle of two-phase samples, the anatase nuclei are surrounded by a rutile envelope. Content of anatase in the two-phase particles varied between 20 and 80%. Particles of all theTiO2samples had a globular shape of diameter between 10 and 30μm. When compared to the corresponding technical-grade samples, the optically pure anatase and rutile demonstrated higher photocatalytic activity in the destruction of tetradecylpyridinium chloride, Methylene Blue and tetrachlorofluorescein as well as in reduction ofCr2O7,MnO4,[Fe(CN)6]3−and[Fe(CN)6]4−. The photocatalytic reactions bring about the reduction of the inorganic anions to yield water insoluble substances and mineralization of the organic compounds. Rate constant of the all above processes do not depend on specific surface area ofTiO2and adsorption of the substrates on theTiO2samples. The rutile calcined at 1027K exhibits the highest specific rate constants. Exposure toγ-radiation increases photocatalytic activity of the dispersedTiO2. The influence ofTiO2and substrate on the photocatalytic reactions is caused by the influence of these factors on the formation of reactive electron hole pair and on the efficiency of the interfacial electron transfer.


2014 ◽  
Vol 955-959 ◽  
pp. 2521-2525 ◽  
Author(s):  
Shu Qin Wang ◽  
Wen Bo Liu ◽  
Ding Lin Zhang

V-doped TiO2 was prepared by the sol-gel method. The different reaction and preparation conditions of TiO2 and V-doped TiO2were evaluated through the formaldehyde degradation under the visible light. Results showed that the formaldehyde degradation efficiency reached 70.8% when the doping amount of V was 1%(mol), the calcining temperature was 700 oC and pH was 3.5; It improved to 88.5% with 20g activated carbon as support and the 89W energy-saving lamp as light source; The formaldehyde degradation products were H2O and CO2; The specific surface area and pore distribution of TiO2 were analyzed by BET and its crystalline structure was analyzed by XRD,which indicated that mixture of anatase and rutile have large surface area and strong photocatalytic activity due to the V-doping. These suggested that the photocatalytic reactions of formaldehyde included adsorption and photocatalytic oxidation which was obvious for the V-doped TiO2.


2006 ◽  
Vol 951 ◽  
Author(s):  
Sorapong Pavasupree ◽  
Supachai Ngamsinlapasathian ◽  
Yoshikazu Suzuki ◽  
Susumu Yoshikawa

ABSTRACTNanorods/nanoparticles TiO2 with mesoporous structure were synthesized by hydrothermal method at 150 °C for 20 h. The samples characterized by XRD, SEM, TEM, SAED, HRTEM, and BET surface area. The nanorods had diameter about 10-20 nm and the lengths of 100-200 nm, the nanoparticles had diameter about 5-10 nm. The prepared material had average pore diameter about 7-12 nm. The BET surface area and pore volume of the sample are about 203 m2/g and 0.655 cm3/g, respectively. The nanorods/nanoparticles TiO2 with mesoporous structure showed higher photocatalytic activity (I3− concentration) than the nanorods TiO2, nanofibers TiO2, mesoporous TiO2, and commercial TiO2 (ST-01, P-25, JRC-01, and JRC-03). The solar energy conversion efficiency (η) of the cell using nanorods/nanoparticles TiO2 with mesoporous structure was about 7.12 % with Jsc of 13.97 mA/cm2, Voc of 0.73 V and ff of 0.70; while η of the cell using P-25 reached 5.82 % with Jsc of 12.74 mA/cm2, Voc of 0.704 V and ff of 0.649.


2021 ◽  
Author(s):  
L.F. Chen ◽  
U. Arellano ◽  
J.A. Wang ◽  
L.M. Balcázar ◽  
R. Sotelo ◽  
...  

Author(s):  
Fengjuan Ge ◽  
Jie Zhu ◽  
Yan Xu ◽  
Jing Li ◽  
Xueyang Zhang

BiOBr photocatalysts were prepared by changing the solvent and synthesis method. SEM, XRD and BET characterization shows that the sample prepared in high-viscosity solution by precipitation method has tremella-like microstructure, with smaller size and higher surface area. Among them, the BiOBr prepared in glycerol solution (GR-P) has the highest surface area of 113.8 m2⋅[Formula: see text]. XRD also indicates that the GR-P has much more exposed (110) facets than other samples. The Rhodamine B degradation tests show that the GR-P has the best activity on both deethylation and aromatic ring destruction steps, indicating that the exposed (110) facets promote the degradation process.


2020 ◽  
Vol 20 (6) ◽  
pp. 1392
Author(s):  
Leny Yuliati ◽  
Mohd Hayrie Mohd Hatta ◽  
Siew Ling Lee ◽  
Hendrik Oktendy Lintang

In this work, the crystalline carbon nitride photocatalysts were synthesized by an ionothermal technique with varied synthesis temperature of 500, 550, and 600 °C, and synthesis time of 2, 4, and 6 h. Fourier transform infrared spectra showed the successful formation of the prepared carbon nitrides from their characteristic vibration peaks. X-ray diffraction patterns suggested that the same phase of poly(triazine imide) and heptazine could be observed, but with different crystallinity. The optical properties showed that different temperatures and synthesis time resulted in the different band gap energy (2.72–3.02 eV) as well as the specific surface area (24–73 m2 g–1). The transmission electron microscopy image revealed that the crystalline carbon nitride has a near-hexagonal prismatic crystallite size of about 50 nm. Analysis by high-performance liquid chromatography showed that the best photocatalytic activity for phenol degradation under solar light simulator was obtained on the crystalline carbon nitride prepared at the 550 °C for 4 h, which would be due to the high crystallinity, suitable low band gap energy (2.82 eV), and large specific surface area (73 m2 g–1). Controlling both the temperature and synthesis time is shown to be important to obtain the best physicochemical properties leading to high activity.


2011 ◽  
Vol 206 (3) ◽  
pp. 306-311 ◽  
Author(s):  
Sungmin Chin ◽  
Eunseuk Park ◽  
Minsu Kim ◽  
Juyoung Jeong ◽  
Gwi-Nam Bae ◽  
...  

2018 ◽  
Vol 445 ◽  
pp. 376-382 ◽  
Author(s):  
Faten Ajala ◽  
Abdessalem Hamrouni ◽  
Ammar Houas ◽  
Hinda Lachheb ◽  
Bartolomeo Megna ◽  
...  

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