scholarly journals A novel Nb2O5/Bi2WO6 heterojunction photocatalytic oxidative desulfurization catalyst with high visible light-induced photocatalytic activity

RSC Advances ◽  
2017 ◽  
Vol 7 (81) ◽  
pp. 51046-51054 ◽  
Author(s):  
Jing Wu ◽  
Jian Li ◽  
Jin Liu ◽  
Jin Bai ◽  
Lina Yang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Oxidative Desulfurization ◽  
Reactive Species ◽  
Superoxide Radicals

A novel Nb2O5/Bi2WO6 heterojunction catalyst was synthesized and applied in PODS of DBT. It shows higher activity than pure Nb2O5 and Bi2WO6 in visible light induced PODS of DBT, in which holes and superoxide radicals are the main reactive species.

scholarly journals Neodymium-DopedTiO2with Anatase and Brookite Two Phases: Mechanism for Photocatalytic Activity Enhancement under Visible Light and the Role of Electron

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Douga Nassoko ◽  
Yan-Fang Li ◽  
Jia-Lin Li ◽  
Xi Li ◽  
Ying Yu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Organic Pollutant ◽  
Sol Gel ◽  
Reactive Species ◽  
X Ray ◽  
Photogenerated Electrons

Titanium dioxide (TiO2) doped with neodymium (Nd), one rare earth element, has been synthesized by a sol-gel method for the photocatalytic degradation of rhodamine-B under visible light. The prepared samples are characterized by X-ray diffractometer, Raman spectroscopy, UV-Vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller measurement. The results indicate that the prepared samples have anatase and brookite phases. Additionally, Nd as Nd3+may enter into the lattice ofTiO2and the presence of Nd3+substantially enhances the photocatalytic activity ofTiO2under visible light. In order to further explore the mechanism of photocatalytic degradation of organic pollutant, photoluminescence spectrometer and scavenger addition method have been employed. It is found that hydroxide radicals produced by Nd-dopedTiO2under visible light are one of reactive species for Rh-B degradation and photogenerated electrons are mainly responsible for the formation of the reactive species.

scholarly journals Constructing BiOBr/g-C3N4/Bi2O2CO3 Z-Scheme Photocatalyst With Enhanced Photocatalytic Activity

2021 ◽  
Author(s):  
Biao Zhang ◽  
Yu Liu ◽  
Kanghong Zhou ◽  
Hongyu Zhu ◽  
Dongxu Gu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Hydrothermal Method ◽  
Rhodamine B ◽  
Charge Separation ◽  
Degradation Process ◽  
Reactive Species ◽  
Promising Material ◽  
Enhanced Absorption ◽  
Radical Trapping

Abstract Novel camellia-structured Z-scheme BiOBr/g-C3N4/Bi2O2CO3 was simply prepared by a hydrothermal method and photodegraded Rhodamine B under visible light within 60 min with much higher degradation efficiency (98%) contrasted with pure BiOBr, g-C3N4 and Bi2O2CO3. Radical trapping experiments exhibited the main reactive species (·O2-) during degradation process. The formation of Z-scheme heterojunction improved rate of charge separation, enhanced absorption of visible light and thus promoted the photocatalytic activity. The Z-scheme heterojunction is a promising material for the removal of dye in effluents.

Impact of Rutile Fraction on TiO2 Visible-Light Absorption and Visible-Light-Induced Photocatalytic Activity

2018 ◽  
Author(s):  
David Maria Tobaldi ◽  
Luc Lajaunie ◽  
ana caetano ◽  
nejc rozman ◽  
Maria Paula Seabra ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Solid Phase ◽  
Diffraction Method ◽  
Band Alignment ◽  
Quantitative Phase Analysis ◽  
Transmission Microscopy ◽  
Visible Light Absorption ◽  
X Ray

<div>Titanium dioxide is by far the most utilised semiconductor material for photocatalytic applications. Still, it is transparent to visible-light. Recently, it has been proved that a type-II band alignment for the rutile−anatase mixture would improve its visible-light absorption.</div><div>In this research paper we thoroughly characterised the real crystalline and amorphous phases of synthesised titanias – thermally treated at different temperatures to get distinct ratios of anatase-rutile-amorphous fraction – as well as that of three commercially available photocatalytic nano-TiO2. </div><div>The structural characterisation was done via advanced X-ray diffraction method, namely the Rietveld-RIR method, to attain a full quantitative phase analysis of the specimens. The microstructure was also investigated via an advanced X-ray method, the whole powder pattern modelling. These methods were validated combining advanced aberration-corrected scanning transmission microscopy and high-resolution electron energy-loss spectroscopy. The photocatalytic activity was assessed in the liquid- and gas-solid phase (employing rhodamine B and 4-chlorophenol, and isopropanol, respectively, as the organic substances to degrade) using a light source irradiating exclusively in the visible-range.</div><div>Optical spectroscopy showed that even a small fraction of rutile (2 wt%) is able to shift to lower energies the apparent optical band gap of an anatase-rutile mixed phase. But is this enough to attain a real photocatalytic activity promoted by merely visible-light?</div><div>We tried to give a reply to that question.</div><div>Photocatalytic activity results in the liquid-solid phase showed that a high surface hydroxylation led to specimen with superior visible light-induced catalytic activity (i.e. dye and ligand-to-metal charge transfer complexes sensitisation effects). That is: not photocatalysis <i>sensu-strictu</i>.</div><div>On the other hand, the gas-solid phase results showed that a higher amount of the rutile fraction (around 10 wt%), together with less recombination of the charge carriers, were more effective for an actual photocatalytic oxidation of isopropanol.</div>

Synthesis of Visible Light Responsive N Doped TiO2 Photocatalyst and its Enhanced Photocatalytic Activity

2015 ◽  
Vol 11 (4) ◽  
pp. 447-452 ◽  
Author(s):  
Yujie Zhao ◽  
Huayang Li ◽  
Hari Bala ◽  
Jingkuo Chen ◽  
Bowen Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light

Preparation of Carbon Coated FeWO4 and its Photocatalytic Activity Under Visible Light~!2008-10-27~!2008-11-26~!2008-12-31~!

2010 ◽  
Vol 2 (1) ◽  
pp. 56-59 ◽  
Author(s):  
Hany H. Abdel Ghafar ◽  
Michio Inagaki ◽  
Tomoki Tsumura ◽  
Masahiro Toyoda
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Carbon Coated

Tuning the Photocatalytic Performance of Plasmonic Nanocomposites (ZnO/Aux) Driven in Visible Light

2019 ◽  
Vol 8 (1) ◽  
pp. 56-61
Author(s):  
Aneeya K. Samantara ◽  
Debasrita Dash ◽  
Dipti L. Bhuyan ◽  
Namita Dalai ◽  
Bijayalaxmi Jena
Keyword(s):  
Electron Transfer ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Transfer Rate ◽  
Photocatalytic Performance ◽  
Light Exposure ◽  
Au Nanoparticle ◽  
Electron Transfer Rate ◽  
Au Nps ◽  
Zno Nanostructure

: In this article, we explored the possibility of controlling the reactivity of ZnO nanostructures by modifying its surface with gold nanoparticles (Au NPs). By varying the concentration of Au with different wt% (x = 0.01, 0.05, 0.08, 1 and 2), we have synthesized a series of (ZnO/Aux) nanocomposites (NCs). A thorough investigation of the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface has been carried out. It was observed that ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity among all concentrations of Au on the ZnO surface, which degrades the dye concentration within 2 minutes of visible light exposure. It was further revealed that with an increase in the size of plasmonic nanoparticles beyond 0.08%, the accessible surface area of the Au nanoparticle decreases. The photon absorption capacity of Au nanoparticle decreases beyond 0.08% resulting in a decrease in electron transfer rate from Au to ZnO and a decrease of photocatalytic activity. Background: Due to the industrialization process, most of the toxic materials go into the water bodies, affecting the water and our ecological system. The conventional techniques to remove dyes are expensive and inefficient. Recently, heterogeneous semiconductor materials like TiO2 and ZnO have been regarded as potential candidates for the removal of dye from the water system. Objective: To investigate the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface and the effect of the size of Au NPs for photocatalytic performance in the degradation process. Methods: A facile microwave method has been adopted for the synthesis of ZnO nanostructure followed by a reduction of gold salt in the presence of ZnO nanostructure to form the composite. Results: ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity which degrades the dye concentration within 2 minutes of visible light exposure. The schematic mechanism of electron transfer rate was discussed. Conclusion: Raspberry shaped ZnO nanoparticles modified with different percentages of Au NPs showed good photocatalytic behavior in the degradation of dye molecules. The synergetic effect of unique morphology of ZnO and well anchored Au nanostructures plays a crucial role.

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