A novel ternary MQDs/NCDs/TiO2 nanocomposite that collaborates with activated persulfate for efficient RhB degradation under visible light irradiation

2021 ◽  
Author(s):  
Qian Zhang ◽  
Han Zhao ◽  
Yuming Dong ◽  
Xiangmiao Zhu ◽  
Xiang Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Absorption ◽  
Absorption Capacity ◽  
Hole Transport ◽  
Light Irradiation ◽  
Pollutant Degradation ◽  
Electron Hole ◽  
Activated Persulfate

TiO2 nanosheets modified with dual MQDs/NCD quantum dots not only promote light absorption capacity and electron–hole transport but also collaborate well with activated persulfate for pollutant degradation.

Effective removal of colourless pollutants and organic dyes by Ag@AgCl nanoparticle-modified CaSn(OH)6 composite under visible light irradiation

2017 ◽  
Vol 41 (13) ◽  
pp. 5334-5346 ◽  
Author(s):  
Chao Liang ◽  
Cheng-Gang Niu ◽  
Xiao-Ju Wen ◽  
Shi-Feng Yang ◽  
Mao-Cai Shen ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Absorption ◽  
Organic Dyes ◽  
Light Irradiation ◽  
Electron Hole ◽  
Visible Light Absorption ◽  
Effective Removal ◽  
Agcl Nanoparticles

The Ag@AgCl nanoparticles could broaden visible-light absorption of pure CSH and depress the recombination of photoinduced electron–hole pairs.

A simple method to synthesise Ag-doped TiO2 photocatalysts with different Ag0:Ag2O atomic ratios for enhancing visible-light photocatalytic activity

2017 ◽  
Vol 41 (8) ◽  
pp. 475-483 ◽  
Author(s):  
C. Chen ◽  
X. F. Lei ◽  
M. Z. Xue
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Absorption ◽  
Separation Efficiency ◽  
Visible Region ◽  
Light Irradiation ◽  
Electron Hole ◽  
X Ray

Pure anatase TiO2 photocatalysts with different Ag contents were prepared via a simple sol-gel method. The as-prepared anatase Ag-doped TiO2 photocatalysts were characterised by X-ray diffraction, transmission electron microscopy, UV-Vis diffuse reflectance spectra, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, thermal gravity and differential thermal analysis, scanning electron microscopy and N2 adsorption–desorption measurements (BET). Compared with pure TiO2, Ag-doped anatase TiO2 photocatalysts exhibited not only increases in light absorption in the visible region, the separation efficiency of electron–hole pairs and surface area, but also inhibition of the titania phase transition from anatase to rutile. Photoreduction results showed that Ag-doped anatase TiO2 photocatalysts have greatly improved photocatalytic activity, compared with pure TiO2, and the reduction of Cr(VI) under visible light irradiation was much higher than that of pure TiO2. The optimum Ag content was 1.0 mol%, which led to the complete reduction of Cr(VI) under visible light irradiation (λ > 420 nm) for 4 h. The enhanced photocatalytic activity was attributed to the synergic effect of the pure anatase structure, and the increased light absorption in the visible region, separation efficiency of electron–hole pairs and atomic ratio of Ag0:Ag2O.

scholarly journals Synthesis, Analysis, and Testing of BiOBr-Bi2WO6Photocatalytic Heterojunction Semiconductors

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Xiangchao Meng ◽  
Zisheng Zhang
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Degradation Process ◽  
Light Irradiation ◽  
Enhancement Effect ◽  
Electron Hole ◽  
Experimental Conditions ◽  
Synthesis Conditions ◽  
Optimum Synthesis ◽  
Photocatalytic Activities

In photocatalysis, the recombination of electron-hole pairs is generally regarded as one of its most serious drawbacks. The synthesis of various composites with heterojunction structures has increasingly shed light on preventing this recombination. In this work, a BiOBr-Bi2WO6photocatalytic heterojunction semiconductor was synthesized by the facile hydrothermal method and applied in the photocatalytic degradation process. It was determined that both reaction time and temperature significantly affected the crystal structure and morphologies of the photocatalysts. BiOBr (50 at%)-Bi2WO6composites were prepared under optimum synthesis conditions (120°C for 6 h) and by theoretically analyzing the DRS results, it was determined that they possessed the suitable band gap (2.61 eV) to be stimulated by visible-light irradiation. The photocatalytic activities of the as-prepared photocatalysts were evaluated by the degradation ofRhodamine B (RhB)under visible-light irradiation. The experimental conditions, including initial concentration, pH, and catalyst dosage, were explored and the photocatalysts in this system were proven stable enough to be reused for several runs. Moreover, the interpreted mechanism of the heterojunction enhancement effect proved that the synthesis of a heterojunction structure provided an effective method to decrease the recombination rate of the electron-hole pairs, thereby improving the photocatalytic activity.

scholarly journals Synthesis of Carbon Doped TiO2 Quantum Dots for Photocatalytic Sterilization under the Visible Light Irradiation and the Mechanisms

2019 ◽  
Vol 118 ◽  
pp. 01013 ◽  
Author(s):  
Wei Xiong ◽  
Altair T.F. Cheung ◽  
Michael K.H. Leung
Keyword(s):  
Quantum Dots ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Superoxide Radical ◽  
Light Irradiation ◽  
Doping Amount ◽  
E Coli ◽  
Carbon Doped ◽  
Chemical States ◽  
Self Protection

In this article, the carbon doped TiO2 (C-TiO2) quantum dots (QDs) were prepared through the hydrothermal method and calcination. The size of the C-TiO2 QDs is about 5.7 nm. The doping amount of carbon can be tuned by adjusting the volumes of the carbon source, ethylene glycol added. The carbon atoms are proved to be doped into the interstitial sites of TiO2 lattice and induce the change of chemical states of Ti 2p and C 1s. The doping of carbon leads to the increasing photocatalytic sterilization of E. coli under the visible light irradiation. The survival rate of E. coli cells over C-TiO2 is only 1.5 % after 6 h. The reactive oxygen species (ROS), such as hydroxyl radical and superoxide radical, are considered as the primary factors for the photocatalytic sterilization. Due to oxidative stress of the attack by ROS, the enzyme activity per cells increases for self-protection during the photocatalytic sterilization.

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