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.

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.

KCl-mediated dual electronic channels in layered g-C3N4 for enhanced visible light photocatalytic NO removal

Nanoscale ◽  
2018 ◽  
Vol 10 (17) ◽  
pp. 8066-8074 ◽  
Author(s):  
Ting Xiong ◽  
Hong Wang ◽  
Ying Zhou ◽  
Yanjuan Sun ◽  
Wanglai Cen ◽  
...  
Keyword(s):  
Visible Light ◽  
Recombination Rate ◽  
Charge Carriers ◽  
Electron Hole ◽  
No Removal ◽  
Electronic Channel ◽  
Hole Recombination ◽  
Electronic Channels ◽  
Co Doped ◽  
Visible Light Photocatalytic

K and Cl ions co-doped into a g-C3N4 interlayer function as a dual electronic channel for electron and hole transfer, thus effectively decreasing the electron–hole recombination rate and prolonging the lifetime of charge carriers.

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.

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

scholarly journals Synthesis and characterization of black TiO2/graphene composites with enhanced photocatalysis

2020 ◽  
Author(s):  
Zhaoqing Li ◽  
Zhufeng Liu ◽  
Xiao Yang ◽  
Peng Chen ◽  
Lei Yang ◽  
...  
Keyword(s):  
Visible Light ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Photogenerated Electron ◽  
Catalytic Performance ◽  
Attractive Potential ◽  
Electron Hole ◽  
Hole Recombination

Abstract According to the composite design, a series of black TiO2/graphene composites were synthesized to improve its photocatalytic activity. TiO2 is generated in situ on the surface of graphene by a facile sol-gel method. The combination of graphene and TiO2 was beneficial for eliminating the opportunity of photogenerated electron-hole recombination due to the excellent conductivity of graphene. In the subsequent hydrogenation process, the self-doping Ti3+ was introduced accompanied by the crystallization of amorphous TiO2. The narrowed bandgap caused by self-doping Ti3+ enhanced the visible light absorption and make the composites appear black. Both of them improved the photocatalytic performance of the synthesized black TiO2/graphene composites. The band structure of the composite was analyzed by valence band XPS, revealing the reason for the high visible light catalytic performance of the composite. The results proved that the black TiO2/graphene composites synthesized show attractive potential for applications in environmental and energy issues.

Perylene Tetracarboxylic Tetraester Sensitized Titanium Dioxide Nanocomposite for Enhanced Photodegradation

NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050100
Author(s):  
Fengxia Zhang ◽  
Haining Liu ◽  
Tianyi Jiang ◽  
Yanyan Zhu ◽  
Xiushen Ye ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Dye Degradation ◽  
Butyl Ester ◽  
Charge Carriers ◽  
Photoluminescence Intensity ◽  
Radical Scavengers ◽  
Electron Hole ◽  
Ft Ir ◽  
Hole Recombination ◽  
Active Substances

The construction of organic–inorganic hybrids is one of the important ways to improve performances of photocatalysts. In this study, perylene tetracarboxylic tetra (n-butyl) ester loaded titanium dioxide (PTTE-B/TiO2) nanocomposite was successfully synthesized by hydrothermal method. The catalyst was characterized by XRD, DRS, XPS, Photoluminescence spectroscopy (PL) and BET. FT-IR and XPS analyses revealed the presence of Ti[Formula: see text]O bond in the interfaces between TiO2 and PTTE-B. The photoluminescence intensity of PTTE-B/TiO2 was decreased compared to TiO2, which indicated a suppression of electron–hole recombination by the loaded PTTE-B nanoparticles. The photocatalytic activity of PTTE-B/TiO2 nanocomposite for degradation of EBT using visible light was higher than that of prepared TiO2 or TiO2-P25. The detection of radical scavengers confirmed that h[Formula: see text] and [Formula: see text] were the main active substances for Eriochrome Black T (EBT, an azo dye) degradation. The Ti[Formula: see text]O bond acted as a short and fast channel for photogenerated charge carriers to migrate from PTTE-B to TiO2. Furthermore, PTTE-B/TiO2 was found to be stable and reusable.

scholarly journals The Sonophotocatalytic Degradation of Pharmaceuticals in Water by MnOx-TiO2 Systems with Tuned Band-Gaps

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 949 ◽  
Author(s):  
Zahra Khani ◽  
Dalma Schieppati ◽  
Claudia L. Bianchi ◽  
Daria C. Boffito
Keyword(s):  
Advanced Oxidation Processes ◽  
Sol Gel ◽  
Pulse Length ◽  
Visible Region ◽  
Band Gaps ◽  
Electron Hole ◽  
Oxidation Processes ◽  
Power Pulse ◽  
Mn Doped ◽  
Hole Recombination

Advanced oxidation processes (AOPs) are technologies to degrade organic pollutants to carbon dioxide and water with an eco-friendly approach to form reactive hydroxyl radicals. Photocatalysis is an AOP whereby TiO2 is the most adopted photocatalyst. However, TiO2 features a wide (3.2 eV) and fast electron-hole recombination. When Mn is embedded in TiO2, it shifts the absorption wavelength towards the visible region of light, making it active for natural light applications. We present a systematic study of how the textural and optical properties of Mn-doped TiO2 vary with ultrasound applied during synthesis. We varied ultrasound power, pulse length, and power density (by changing the amount of solvent). Ultrasound produced mesoporous MnOx-TiO2 powders with a higher surface area (101–158 m2 g−1), pore volume (0-13–0.29 cc g−1), and smaller particle size (4–10 µm) than those obtained with a conventional sol-gel method (48–129 m2 g−1, 0.14–0.21 cc g−1, 181 µm, respectively). Surprisingly, the catalysts obtained with ultrasound had a content of brookite that was at least 28%, while the traditional sol-gel samples only had 7%. The samples synthesized with ultrasound had a wider distribution of the band-gaps, in the 1.6–1.91 eV range, while traditional ones ranged from 1.72 eV to 1.8 eV. We tested activity in the sonophotocatalytic degradation of two model pollutants (amoxicillin and acetaminophen). The catalysts synthesized with ultrasound were up to 50% more active than the traditional samples.

Synergic effects of upconversion nanoparticles NaYbF4:Ho3+ and ZrO2 enhanced the efficiency in hole-conductor-free perovskite solar cells

Nanoscale ◽  
2018 ◽  
Vol 10 (46) ◽  
pp. 22003-22011 ◽  
Author(s):  
Yanyan Li ◽  
Li Zhao ◽  
Meng Xiao ◽  
Yimin Huang ◽  
Binghai Dong ◽  
...  
Keyword(s):  
Solar Cells ◽  
Visible Light ◽  
Recombination Rate ◽  
Perovskite Solar Cells ◽  
Upconversion Nanoparticles ◽  
Electron Hole ◽  
Dual Functional ◽  
Nir Light ◽  
Hole Recombination

This design enabled the dual-functional effects, that is, the harvesting of NIR light and its conversion to visible light and the reduction of the electron–hole recombination rate.

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