Synthesis of Bi2WO6/g-C3N4 photocatalyst and high degradation of Rhodamine B under visible light irradiation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wenjie Wang ◽  
Mengran Zhang ◽  
Binxia Zhao ◽  
Linxue Liu ◽  
Ruixuan Han ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Rhodamine B ◽  
Hydrothermal Reaction ◽  
Active Species ◽  
High Photocatalytic Activity ◽  
Rapid Separation ◽  
Content Type ◽  
Photogenerated Electrons ◽  
Molecular Substances ◽  
Photocatalytic Material

Purpose The purpose of this paper is to improve the degradation efficiency of Rhodamine B (RhB) by new photocatalytic materials. Design/methodology/approach Binary Z-scheme g-C3N4/Bi2WO6 photocatalytic material was synthesized by the one-step hydrothermal reaction. The construction of Z-scheme heterojunction led to the rapid separation of photogenerated electrons and holes, which would degrade RhB into small molecular substances to achieve the purpose of degradation. Findings It was found that Bi2WO6/25%g-C3N4 displayed the highest photocatalytic activity, which was about 1.44 and 1.34 times higher than that of pure Bi2WO6 and g-C3N4, respectively. According to the trapping experiments, the superoxide radical (·O2−) was the major active species of the RhB decomposition in Bi2WO6/g-C3N4 catalysts. Originality/value The successful synthesis of Z-scheme Bi2WO6/g-C3N4 provides new ideas and references for the design of catalysts with high photocatalytic activity, which should have wide applications in the future.

scholarly journals Preparation and Characterization of Defective TiO2. The Effect of the Reaction Environment on Titanium Vacancies Formation

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2763
Author(s):  
Zuzanna Bielan ◽  
Szymon Dudziak ◽  
Agnieszka Sulowska ◽  
Daniel Pelczarski ◽  
Jacek Ryl ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Reaction ◽  
High Photocatalytic Activity ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Light Activity ◽  
Cheap Alternative

Among various methods of improving visible light activity of titanium(IV) oxide, the formation of defects and vacancies (both oxygen and titanium) in the crystal structure of TiO2 is an easy and relatively cheap alternative to improve the photocatalytic activity. In the presented work, visible light active defective TiO2 was obtained by the hydrothermal reaction in the presence of three different oxidizing agents: HIO3, H2O2, and HNO3. Further study on the effect of used oxidant and calcination temperature on the physicochemical and photocatalytic properties of defective TiO2 was performed. Obtained nanostructures were characterized by X-ray diffractometry (XRD), specific surface area (BET) measurements, UV-Vis diffuse reflectance spectroscopy (DR-UV/Vis), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR) spectroscopy. Degradation of phenol as a model pollutant was measured in the range of UV-Vis and Vis irradiation, demonstrating a significant increase of photocatalytic activity of defective TiO2 samples above 420 nm, comparing to non-defected TiO2. Correlation of EPR, UV-Vis, PL, and photodegradation results revealed that the optimum concentration of HIO3 to achieve high photocatalytic activity was in the range of 20–50 mol%. Above that dosage, titanium vacancies amount is too high, and the obtained materials’ photoactivity was significantly decreased. Studies on the photocatalytic mechanism using defective TiO2 have also shown that •O2− radical is mainly responsible for pollutant degradation.

scholarly journals Pt Nanowire-Anchored Dodecahedral Ag3PO4{110} Constructed for Significant Enhancement of Photocatalytic Activity and Anti-Photocorrosion Properties: Spatial Separation of Charge Carriers and PhotogeneratedElectron Utilization

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 206
Author(s):  
Hanxu Zhu ◽  
Yekun Ji ◽  
Lifang Chen ◽  
Weilin Bian ◽  
Jinnan Wang
Keyword(s):  
Photocatalytic Activity ◽  
Electronic Conductivity ◽  
Active Species ◽  
The Body ◽  
Charge Carriers ◽  
Cubic Phase ◽  
Long Distance ◽  
Photogenerated Electrons ◽  
O2 Reduction ◽  
Pt Nanowires

Pt nanowire-anchored dodecahedral Ag3PO4{110} was constructed for organics photodegradation. SEM and TEM images confirmed that the Pt nanowires were grafted on dodecahedral Ag3PO4, which was entirely bounded by {110} facets. All the X-ray diffraction peaks of the samples were indexed to the body-centered cubic phase of Ag3PO4, indicating that Pt nanowire-anchored dodecahedral Ag3PO4 well maintained the original crystal structure. The rhombic dodecahedral Ag3PO4 entirely bounded by {110} facets achieved high photocatalytic activity. Due to the formation of a Schottky barrier, the Pt nanowires improved the separation of the charge carriers of Ag3PO4. Furthermore, they provided a fast expressway to transfer the photogenerated electrons and prolonged the lifetime of the charge carriers via long-distance transport, resulting in the accumulation of holes on Ag3PO4 for organics degradation. More importantly, the Pt nanowires improved the reduction potential of the photogenerated electrons for O2 reduction to ·O2−, which enhanced the photocatalytic activity and anti-photocorrosion properties of Ag3PO4. We found that 99.5% of Rhodamine B (RhB) could be removed over 0.5ωt% Pt nanowire-anchored dodecahedral Ag3PO4 within 10 min. Even after 10 cycles, the photocatalytic activity was still high. photoluminescence (PL), time-resolved photoluminescence (TRPL), UV–vis diffuse reflectance spectra (UV–visDRS), and photoelectrochemical analysis showed that Pt nanowire-anchored dodecahedral Ag3PO4 exhibited lower bandgap, higher photocurrent intensity, better electronic conductivity, and longer charge carriers lifetime than other types of Ag3PO4 crystals. Radical trapping experiments and electron paramagnetic resonance (EPR) analysis demonstrated that the holes were the main active species for organics photodegradation.

scholarly journals Dye-sensitized Pt@TiO2 core–shell nanostructures for the efficient photocatalytic generation of hydrogen

2014 ◽  
Vol 5 ◽  
pp. 360-364 ◽  
Author(s):  
Jun Fang ◽  
Lisha Yin ◽  
Shaowen Cao ◽  
Yusen Liao ◽  
Can Xue
Keyword(s):  
Photocatalytic Activity ◽  
High Photocatalytic Activity ◽  
Shell Structures ◽  
Core Shell ◽  
Synergic Effect ◽  
Proton Reduction ◽  
Dye Sensitization ◽  
Dye Sensitized ◽  
Shell Nanostructures ◽  
Photogenerated Electrons

Pt@TiO2 core–shell nanostructures were prepared through a hydrothermal method. The dye-sensitization of these Pt@TiO2 core–shell structures allows for a high photocatalytic activity for the generation of hydrogen from proton reduction under visible-light irradiation. When the dyes and TiO2 were co-excited through the combination of two irradiation beams with different wavelengths, a synergic effect was observed, which led to a greatly enhanced H2 generation yield. This is attributed to the rational spatial distribution of the three components (dye, TiO2, Pt), and the vectored transport of photogenerated electrons from the dye to the Pt particles via the TiO2 particle bridge.

scholarly journals Hydrazine and Urea Fueled-Solution Combustion Method for Bi2O3 Synthesis: Characterization of Physicochemical Properties and Photocatalytic Activity

2019 ◽  
Vol 15 (1) ◽  
pp. 104-111 ◽  
Author(s):  
Yayuk Astuti ◽  
Prisca Putri Elesta ◽  
Didik Setyo Widodo ◽  
Hendri Widiyandari ◽  
Ratna Balgis
Keyword(s):  
Crystal Structure ◽  
Photocatalytic Activity ◽  
Bismuth Oxide ◽  
Rhodamine B ◽  
Combustion Method ◽  
High Photocatalytic Activity ◽  
Synthesis Process ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
Structure Morphology

Bismuth oxide synthesis using solution combustion method fuelled by hydrazine and urea has been conducted. This study aims to examine the effect of the applied fuels, urea and hydrazine, on product characteristics and photocatalytic activity in degrading rhodamine B dye. Bismuth oxide synthesis was initiated by dissolving bismuth nitrate pentahydrate (Bi(NO3)3.5H2O) in a nitric acid solvent. Fuel was added and then stirred. The solution formed was heated at 300 ºC for 8 hours. The product obtained was then calcined at 700 ºC for 4 hours. Bismuth oxide synthesized with urea (BO1) and hydrazine (BO2) as fuels both obtained form of yellow powder. The formation of bismuth oxide is indicated by the vibrations of the Bi–O–Bi and Bi–O groups and the crystal structure of a-Bi2O3 in both products. Photocatalytic activity test showed that BO1 has a photocatalyst activity in degrading rhodamine B higher than that of BO2 with constant values of  3.83×10-5 s-1 and 3.43×10-5 s-1, respectively. The high photocatalytic activity can be examined through several factors, such as: band gap values, crystal structure, morphology, and surface area, acquired as a result of the use of different fuels in the synthesis process. Copyright © 2020 BCREC Group. All rights reserved 

scholarly journals Preparation and Characterization of Cu-doped TiO2 nanomaterials with Anatase/rutile/brookite Triphasic Structure and their Photocatalytic Activity

2021 ◽  
Author(s):  
Xiaodong Zhu ◽  
Qin Zhou ◽  
Yangwen Xia ◽  
Juan Wang ◽  
Hongjin Chen ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Electron Microscope ◽  
Hydrothermal Process ◽  
Degradation Process ◽  
High Photocatalytic Activity ◽  
Photoelectron Spectra ◽  
X Ray ◽  
Surface Areas ◽  
Photogenerated Electrons ◽  
Degradation Degree

Abstract Pure TiO2 and different concentrations of Cu–doped TiO2 with anatase/rutile/brookite triphasic structure were successfully synthesized through a simple hydrothermal process and characterized by X–ray diffraction (XRD), Raman, scanning electron microscope (SEM), transmission electron microscope (TEM), X–ray photoelectron spectra (XPS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL) and Brunauer-Emmett-Teller surface area (BET). Both pure and Cu–doped TiO2 show relatively high photocatalytic activity owing to their considerable surface areas. Moreover, the three–phase coexisting structure and the conversion between Cu2+ and Cu+ ions facilitate the separation of photogenerated electrons and holes, which is favorable for photocatalytic performance. 1%Cu–TiO2 exhibits the highest photocatalytic activity and the degradation degree of rhodamine B (RhB) reaches 93.5% after 30 min, which is higher than that of monophasic/biphasic 1%Cu–TiO2. ·O2− radical is the main active specie, and h+ and ·OH are subsidiary in the degradation process.

Preparation of Bi/Bi2MoO6 Plasmonic Photocatalyst with High Photocatalytic Activity Under Visible Light Irradiation

NANO ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. 1850127 ◽  
Author(s):  
Chentao Zou ◽  
Zhiyuan Yang ◽  
Mengjun Liang ◽  
Yunpeng He ◽  
Yun Yang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Rate Constant ◽  
Active Species ◽  
High Photocatalytic Activity ◽  
Composite Photocatalysts ◽  
Degradation Rate Constant ◽  
Degradation Activity ◽  
Spr Effect

Bi metal deposited on Bi2MoO6 composite photocatalysts have been successfully synthesized via a simple reduction method at room temperature with using NaBH4 as the reducing agent. The photocatalytic activity of the composite was evaluated by degradation of rhodamine B (RhB) and bisphenol A (BPA) solution under visible light. The rate constant of Bi/Bi2MoO6 composite to RhB is 10.8 times that of Bi2MoO6, and the degradation rate constant of BPA is 6.9 times of that of Bi2MoO6. Nitrogen absorption–desorption isotherm proved that the increase of specific surface area is one of the reasons for the improvement of photocatalytic degradation activity of Bi/Bi2MoO6 composites. The higher charge transfer efficiency of Bi/Bi2MoO6 is found through the characterization of the photocurrent and impedance, which are attributed to the surface plasmon resonance (SPR) effect produced by the introduction of the metal Bi monomer in the composite. Free radical capture experiments proved that cavitation is the main active species. Based on the above conclusions, a possible mechanism of photocatalytic degradation is proposed.

Facile hydrothermal synthesis of NaTaO3 with high photocatalytic activity

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940046 ◽  
Author(s):  
Min Yen Yeh ◽  
Jun Hong Li ◽  
Shun Hsyung Chang ◽  
Shiow Yueh Lee ◽  
Huichun Huang
Keyword(s):  
Photocatalytic Activity ◽  
Hydrothermal Synthesis ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Perovskite Structure ◽  
Hydrothermal Reaction ◽  
High Photocatalytic Activity ◽  
Light Irradiation ◽  
Orthorhombic Perovskite

Orthorhombic perovskite structure NaTaO3 with cube shape was successfully synthesized by hydrothermal reaction. The as-prepared NaTaO3 behaves a great photocatalystic activity on degradation of MB solution not only under UV but also visible light irradiation.

Novel one-dimensional Bi2O3–Bi2WO6 p–n hierarchical heterojunction with enhanced photocatalytic activity

2014 ◽  
Vol 2 (22) ◽  
pp. 8517-8524 ◽  
Author(s):  
Yin Peng ◽  
Mei Yan ◽  
Qing-Guo Chen ◽  
Cong-Min Fan ◽  
Hai-Yan Zhou ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Organic Compounds ◽  
Visible Light Irradiation ◽  
Electrostatic Field ◽  
High Photocatalytic Activity ◽  
Light Irradiation ◽  
Junction Region ◽  
One Dimensional ◽  
Photogenerated Electrons

A novel Bi2O3–Bi2WO6 p–n junction photocatalyst exhibits high photocatalytic activity for the degradation of organic compounds under solar/visible light irradiation, which is ascribed to the effective separation of photogenerated electrons and holes by the internal electrostatic field in the junction region.

scholarly journals Photocatalytic Performance and Degradation Pathway of Rhodamine B with TS-1/C3N4 Composite under Visible Light

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 756 ◽  
Author(s):  
Jingjing Yang ◽  
Hongqing Zhu ◽  
Yuan Peng ◽  
Pengxi Li ◽  
Shuyan Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Photocatalytic Performance ◽  
Degradation Products ◽  
Nitrogen Adsorption ◽  
Degradation Pathway ◽  
Active Species ◽  
Photogenerated Electrons

TS-1/C3N4 composites were prepared by calcining the precursors with cooling crystallization method and were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), UV-Vis diffuse reflection spectrum (DRS) and nitrogen adsorption–desorption isotherm. The photocatalytic performance of TS-1/C3N4 composites was investigated to degrade Rhodamine B (RhB) under visible light irradiation. The results showed that all composites exhibited better photocatalytic performance than pristine TS-1 and C3N4; TS-1/C3N4-B composite (the measured mass ratio of TS-1 to C3N4 is 1:4) had best performance, with a rate constant of 0.04166 min−1, which is about two and ten times higher than those of C3N4 and TS-1, respectively. We attributed the enhanced photocatalytic performance of TC-B to the optimized heterostructure formed by TS-1 and C3N4 with proper proportion. From the results of photoluminescence spectra (PL) and the enhanced photocurrent, it is concluded that photogenerated electrons and holes were separated more effectively in TS-1/C3N4 composites. The contribution of the three main active species for photocatalytic degradation followed a decreasing order of ·O2−, ·OH and h+. The degradation products of RhB were identified by liquid chromatography tandem mass spectrometry (LC-MS/MS), and the possible photocatalytic degradation pathways were proposed.

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