scholarly journals Synthesis, characterization and photocatalytic activity of mesoporous Na-doped TiO2 nano-powder prepared via a solvent-controlled non-aqueous sol–gel route

RSC Advances ◽  
2017 ◽  
Vol 7 (85) ◽  
pp. 54053-54062 ◽  
Author(s):  
Inderjeet Singh ◽  
Balaji Birajdar
Keyword(s):  
Photocatalytic Activity ◽  
Catalytic Activity ◽  
Surface Area ◽  
Recombination Rate ◽  
Sol Gel ◽  
Electron Hole ◽  
Photo Catalytic Activity ◽  
Nano Powder ◽  
Hole Recombination ◽  
Enhanced Crystallinity

The superior photo-catalytic activity of mesoporous Na doped TiO2 attributed to the combined effect of electron–hole recombination rate, increased surface area and enhanced crystallinity.

scholarly journals Improved Organic Dye Degradation Using Highly Efficient MXene Composites

2018 ◽  
Author(s):  
M. Abdullah Iqbal ◽  
S. Irfan Ali ◽  
Ayesha Tariq ◽  
Mohammad Z. Iqbal ◽  
Syed Rizwan
Keyword(s):  
Surface Area ◽  
Recombination Rate ◽  
Dye Degradation ◽  
Organic Pollutant ◽  
Sol Gel ◽  
Transition Metal Carbide ◽  
Light Spectrum ◽  
Electron Hole ◽  
Hole Recombination ◽  
Co Doped

Over the years, scarcity of fresh potable water has increased the demand for clean water. Meanwhile, with the advent of nanotechnology, the use of nanomaterials for photocatalytic degradation of pollutants in wastewaters has increased. Herein, a new type of nanohybrids of La and Mn co-doped bismuth ferrite (BiFeO3) nanoparticles embedded into transition metal carbide sheets (MXene) were prepared by a low-cost double solvent sol-gel method, and investigated for their photocatalytic activity. The photoluminescence results showed that pure BFO has highest electron hole recombination rate as compared to all the co-doped BFO/MXene nanohybrids. The larger surface area and higher electron-hole pair generation rate provides suitable environment for fast photo-degradation of organic molecules. The band gap of the prepared nanohybrids was tuned to 1.96 eV having largest BiFeO3 surface area (147 m2g−1) reported till date. Moreover, the BLFO/MXene and BLFMO-5/Mxene degraded the 92% organic pollutant from water in dark and remaining in light spectrum as compare to undoped BFO/Mxene due to enhancement of the surface area and electron-hole recombination rate upon doping. Therefore, these synthesized nanohybrids could be a promising candidate for photocatalytic applications in future.

Synthesis of Ag, Pd-Loaded Bi2WO6 and its Photocatalytic Activities

2012 ◽  
Vol 518-523 ◽  
pp. 833-836 ◽  
Author(s):  
Li Guo ◽  
Dan Jun Wang ◽  
Feng Fu ◽  
Xiao Dan Qiang ◽  
Te Xu
Keyword(s):  
Photocatalytic Activity ◽  
Catalytic Activity ◽  
Charge Carrier ◽  
Experimental Results ◽  
Electron Hole ◽  
Photogenerated Charge Carrier ◽  
Photocatalytic Activities ◽  
Pure Bi2wo6 ◽  
Hole Recombination

Ag, Pd loaded Bi2WO6 photocatalyst were prepared via a photoreduction process and characterized with UV-Vis-DRS, XRD and FE-SEM. The photocatalysis experimental results indicated that the photocatalytic activity of Ag-loaded Bi2WO6 was greatly enhanced compared with pure Bi2WO6, and the content of silver has an impact on the catalytic activity of Ag-loaded Bi2WO6 photocatalyst. The loaded Ag and Pd acts as the electron receptor on the surface of Bi2WO6, which inhibits the recombination of photogenerated charge carrier between Ecb to the Evb in the Ag-loaded Bi2WO6. As a result, the reduction of electron-hole recombination decreased, which could significantly improve the photocatalytic activity.

The Synthesis of Ag Doped TiO2 Powders and Enhanced Photocatalytic Activity for Degradation of Organic Dye in Waste Waters

2013 ◽  
Vol 650 ◽  
pp. 3-6 ◽  
Author(s):  
Li Ming Jiang
Keyword(s):  
Photocatalytic Activity ◽  
Catalytic Activity ◽  
Calcination Temperature ◽  
Rhodamine B ◽  
Sol Gel ◽  
Organic Dye ◽  
Tetrabutyl Titanate ◽  
Waste Waters ◽  
Calcination Time ◽  
Electron Hole

The Ag/TiO2powders with different Ag contents were synthesized with tetrabutyl titanate as a titanium source and silver nitrate as silver source by sol-gel method, and the Ag contents in the Ag/TiO2powders were 0.1%, 0.3%, 0.5 %, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, and 4% (mole ratio) respectively. Meanwhile, Rhodamine B was used as target degradant to value the photocatalytic activity of Ag/TiO2powders, the effects of Ag contents, the calcination temperature and calcination time on the photocatalytic activity were disscussed The results show that catalytic activity of the Ag/TiO2powders prepared with the Ag content of 2%, calcination temperature of 450 °C and calcination time of 2 hours exhibited the best photocatalytic activity, which was ascribed to the abundant electron traps in favor of the separation of the photoinduced electron-hole pairs.

Synthesis, characterization and enhanced visible-light photocatalytic activity of novel NiO/HTi2NbO7nanocomposite

2018 ◽  
Vol 42 (12) ◽  
pp. 10279-10289 ◽  
Author(s):  
Jie Li ◽  
Lei Xu ◽  
Jie He ◽  
Lifang Hu ◽  
Liangguo Da ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Recombination Rate ◽  
Crucial Role ◽  
Electron Hole ◽  
Visible Light Photocatalytic Activity ◽  
Hole Recombination ◽  
Visible Light Photocatalytic

The decreased electron–hole recombination rate of the NiO/HTi2NbO7nanocomposite plays a crucial role in improving visible-light photocatalytic activity.

scholarly journals Correlation of fluorescence and photocatalytic activity of Co-doped TiO2

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Koh Pei Wen ◽  
Leny Yuliati ◽  
Lee Siew Ling
Keyword(s):  
Photocatalytic Activity ◽  
Sol Gel ◽  
Chemical Properties ◽  
Rutile Phase ◽  
Band Gap Energy ◽  
Electron Hole ◽  
Doped Tio2 ◽  
Physical And Chemical ◽  
Hole Recombination ◽  
Co Doped

Co-doped TiO2 (0.5-4 mol%) photocatalysts were synthesized via sol-gel method and their physical and chemical properties were investigated. Addition of Co oxide dopant induced anatase to rutile phase transition and reduced the band gap energy of TiO2. The fluorescence result indicated that the electron-hole recombination rate was reduced with the presence of Co oxide dopant. The best photocatalyst obtained was 3Co-TiO2 which enhanced the photocatalytic activity of TiO2 by 12 folds to 26.6%. The importance of fluorescence properties of Co-doped TiO2 towards its photodegradation of Congo Red was presented.

Enhanced visible-active photocatalytic behaviors observed in Mn-doped BiFeO3

2018 ◽  
Vol 32 (17) ◽  
pp. 1850185 ◽  
Author(s):  
Yun-Hui Si ◽  
Yu Xia ◽  
Ya-Yun Li ◽  
Shao-Ke Shang ◽  
Xin-Bo Xiong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Mn Doped ◽  
Hole Recombination ◽  
Narrow Band Gap Semiconductors

A series of BiFeO3 and BiFe[Formula: see text]Mn[Formula: see text]O3 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by a hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy (EDS) and UV–Vis diffuse reflectance spectroscopy, and their photocatalytic activity was studied by photocatalytic degradation of methylene blue in aqueous solution under visible light irradiation. The band gap of BiFeO3 was significantly decreased from 2.26 eV to 1.90 eV with the doping of Mn. Furthermore, the 6% Mn-doped BiFeO3 photocatalyst exhibited the best activity with a degradation rate of 94% after irradiation for 100 min. The enhanced photocatalytic activity with Mn doping could be attributed to the enhanced optical absorption, increment of surface reactive sites and reduction of electron–hole recombination. Our results may be conducive to design more efficient photocatalysts responsive to visible light among narrow band gap semiconductors.

Suppressing the electron–hole recombination rate in hematite photoanode with a rapid cooling treatment

2017 ◽  
Vol 350 ◽  
pp. 48-55 ◽  
Author(s):  
Jingran Xiao ◽  
Huali Huang ◽  
Qiuyang Huang ◽  
Le Zhao ◽  
Xiang Li ◽  
...  
Keyword(s):  
Recombination Rate ◽  
Electron Hole ◽  
Rapid Cooling ◽  
Hole Recombination

The Effect of Chromium on the Optical Properties and Photoactivity of Nano-Particulate Rutile

2012 ◽  
Vol 554-556 ◽  
pp. 502-506 ◽  
Author(s):  
Li Wei Wang ◽  
Terry A. Egerton
Keyword(s):  
Optical Properties ◽  
Photocatalytic Activity ◽  
Reflectance Spectroscopy ◽  
Electron Trapping ◽  
Electron Hole ◽  
High Chromium ◽  
Chromium Doping ◽  
Chromium Addition ◽  
Co Precipitation ◽  
Hole Recombination

Chromium doped rutile TiO2was synthesized by either co-precipitation or impregnation (surface-doping) and characterized by XRD and reflectance spectroscopy. Chromium addition did not change the TiO2structure nor did the structure of the co-precipitated products differ from that of the impregnated samples. However, chromium doping moved the absorption of both sets of products into the visible and significantly affected the TiO2photocatalytic activity for isopropanol (IPA) oxidation. At high chromium concentrations the photoactivity of the co-precipitated samples was reduced by a larger amount than that of the impregnated samples; this was attributed to a higher concentration of Cr3+ions in the rutile lattice. Unexpectedly, increased photoactivity was measured for low Cr levels of surface-doped rutile. This may be caused by increased electron-trapping, at surface Cr6+ions, and correspondingly reduced, electron-hole recombination.

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