scholarly journals Improvement of the Efficiency of TiO2 Photocatalysts with Natural Dye Sensitizers Anthocyanin for the Degradation of Methylene Blue: Review

2021 ◽  
Vol 16 (2) ◽  
pp. 84-99
Author(s):  
Hendrini Pujiastuti ◽  
Indar Kustiningsih ◽  
Slamet Slamet
Keyword(s):  
Visible Light ◽  
Dye Degradation ◽  
Low Cost ◽  
Electron Excitation ◽  
Band Gap Energy ◽  
Natural Dye ◽  
Tio2 Photocatalyst ◽  
Tio2 Photocatalysts ◽  
Dye Sensitizer ◽  
Potential Methods

One of the potential methods utilized for dye degradation is photocatalitic, due to its low cost, highly effective, and environmentally friendly. Effectivenes of TiO2 photocatalysts can be enhanced by adding a dye sensitizer. Dye-sensitizer material absorbs visible light to facilitate electron excitation process. Addition of dye-sensitizer on TiO2 photocatalyst promotes it to be more responsive to visible light. Natural anthocyanin dyes are often used as sensitizers of TiO2 semiconductors. Anthocyanins are, usually in the purple to the red color range, a group of natural dyes found in the flowers, leaves, and fruit of plants. The essential principles of dye sensitization to TiO2 have been explored in this review. It is feasible to reduce the band gap energy in the TiO2 photocatalyst by modifying it using a natural dye sensitized modification. Dye sensitizers on TiO2 nanotubes plate have the potential to be employed in a dye degradation photocatalytic system

scholarly journals Preparation of Porous F-WO3/TiO2Films with Visible-Light Photocatalytic Activity by Microarc Oxidation

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Chung-Wei Yeh ◽  
Kee-Rong Wu ◽  
Chung-Hsuang Hung ◽  
Hao-Cheng Chang ◽  
Chuan-Jen Hsu
Keyword(s):  
Visible Light ◽  
Dye Degradation ◽  
Microarc Oxidation ◽  
Band Gap Energy ◽  
High Specific Surface Area ◽  
Cross Sectional ◽  
Porous Networks ◽  
Transmission Electron ◽  
Porous Microstructure ◽  
Diffraction Patterns

Porous F-WO3/TiO2(mTiO2) films are prepared on titanium sheet substrates using microarc oxidation (MAO) technique. The X-ray diffraction patterns show that visible-light (Vis) enabling mTiO2films with a very high content of anatase TiO2and high loading of WO3are successfully synthesized at a low applied voltage of 300 V using electrolyte contenting NaF and Na2WO4without subsequent heat treatment. The cross-sectional transmission electron microscopy micrograph reveals that the mTiO2films feature porous networks connected by many micron pores. The diffused reflection spectrum displays broad absorbance across the UV-Vis regions and a significant red shift in the band gap energy (∼2.23 eV) for the mTiO2film. Owing to the high specific surface area from the porous microstructure, the mTiO2film shows a 61% and 50% rate increase in the photocatalytic dye degradation, as compared with the N,C-codoped TiO2films under UV and Vis irradiation, respectively.

scholarly journals Visible-Light-Driven SO42-/TiO2 Photocatalyst Synthesized from Binh Dinh (Vietnam) Ilmenite Ore for Rhodamine B Degradation

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Tan Lam Nguyen ◽  
Viet Dinh Quoc ◽  
Thi Lan Nguyen ◽  
Thi Thanh Thuy Le ◽  
Thanh Khan Dinh ◽  
...  
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Photocatalytic Degradation ◽  
Surface Area ◽  
Rhodamine B ◽  
Low Cost ◽  
Tio2 Photocatalyst ◽  
Tio2 Sample ◽  
Sunlight Irradiation ◽  
Visible Light Driven

A low-cost and simplistic approach for the synthesis of nanosized SO42-/TiO2 photocatalyst was successfully performed using Binh Dinh ilmenite ore and H2SO4 as titanium and sulfur sources, respectively. The experimental results indicate that the obtained material exists in the form of particles with a size of about 22 nm and has a specific surface area of about 49 m2 g-1. Compared with the TiO2 sample, the SO42-/TiO2 sample shows much higher photocatalytic degradation of rhodamine B (RhB) under the sunlight irradiation. In more details, the nanosized SO42-/TiO2 sample obtained is capable of completely decomposing RhB after 9 hours of irradiation by a 60 W LED lamp with a corresponding intensity of 9,500 Lux. However, when the SO42-/TiO2 is irradiated by the sunlight with the intensity of 65,000 Lux, it only takes 2 hours to completely decompose rhodamine B (RhB), facilitating the use of SO42-/TiO2 as a potential photocatalyst for the RhB photodegradation.

scholarly journals One Pot Synthesis of CoTiO3-TiO2 Composite Nanofibers and its Application in Dye Degradation

2021 ◽  
pp. 1597-1607
Author(s):  
M. Shamshi Hassan
Keyword(s):  
Visible Light ◽  
Composite Nanofibers ◽  
Dye Degradation ◽  
Band Gap Energy ◽  
One Pot ◽  
Light Region ◽  
Composite Photocatalysts ◽  
One Step ◽  
Ft Ir ◽  
The One

CoTiO3-TiO2 composite nanofibrous photocatalysts were synthesized by means of the one-step electrospinning method. The samples were characterized by a range of different methods (XRD, SEM, EPMA, FT-IR, UV-DRS, and TEM). Photocatalytic activity was performed for the degradation of rhodamine 6G under visible light. The results showed that CoTiO3-TiO2 composite photocatalysts were successfully synthesized. The average sizes of the diameters of the composite nanofibers were found to be 300 to 400 nm. The UV–Vis diffuse reflectance spectra of the CoTiO3-TiO2 composite showed an absorption wavelength, in the visible light region, having a band gap energy value of 2.21 eV. The CoTiO3-TiO2 composite showed higher photocatalytic efficiency than that of pristine TiO2; which can be attributed to the heterojunctional interaction between CoTiO3 and TiO2.

Vanadium-Decorated Nickel Oxide Nanosheets for Photocatalytic Removal of Malachite Green Dye Using Visible Light

2019 ◽  
Vol 11 (10) ◽  
pp. 1410-1416 ◽  
Author(s):  
A. S. Basaleh
Keyword(s):  
Visible Light ◽  
Nickel Oxide ◽  
Malachite Green ◽  
Photocatalytic Performance ◽  
Dye Degradation ◽  
Weight Percent ◽  
Band Gap Energy ◽  
Bandgap Energy ◽  
Malachite Green Dye ◽  
Photocatalytic Removal

Nickel oxide (NiO) nanosheets were prepared using a hydrothermal method, and vanadiumdecorated nickel oxide nanosheets were prepared using a photoassisted deposition method. The NiO and vanadium-decorated nickel oxide (V @ NiO) photocatalysts were investigated by several techniques, including BET, XPS, PL, UV-Vis, XRD, and TEM. The results demonstrated that the NiO bandgap energy can be adjusted by adjusting the weight percent of decorated vanadium. Malachite green dye degradation under visible light conditions was chosen to measure the photocatalytic performance of the NiO and V @ NiO samples. Additionally, parameters that affect photocatalytic performance, such as the concentration of malachite green dye, dose of the photocatalyst and vanadium weight percent, were studied in detail. The outcomes reveal that V @ NiO samples have photocatalytic activity higher than that of NiO samples due to their ability to hinder the electron–hole recombination rate and decrease the band gap energy.

scholarly journals Photocatalytic degradation of Dyes in Water by Analytical Reagent Grade Photocatalysts – A comparative study

2017 ◽  
Author(s):  
Dnyaneshwar R. Shinde ◽  
Popat S. Tambade ◽  
Manohar G. Chaskar ◽  
Kisan M. Gadave
Keyword(s):  
Photocatalytic Activity ◽  
Metal Oxides ◽  
Dye Degradation ◽  
Low Cost ◽  
Particle Morphology ◽  
Xrd Analysis ◽  
Solar Irradiation ◽  
Tio2 Photocatalyst ◽  
Crystalline Phases ◽  
Analytical Reagent

Abstract. In a search of low cost photocatalyst for dye degradation we have evaluated photocatalytic activity of the Analytical Reagent (AR) grade ZnO, TiO2 and SnO2. The photocatalytic activity was evaluated towards the decolourization of structurally diverse dyes such as crystal violet, basic blue and methyl red under solar irradiation and compared with benchmark Degussa P-25 (TiO2) photocatalyst. The received metal oxides were characterized by the different physicochemical methods of analysis. Powder XRD analysis showed that these metal oxides are polycrystalline in nature and crystallized in different crystalline phases. The crystalline phases of these oxides were found to be hexagonal for ZnO, tetragonal for TiO2 and rutile for SnO2. Particle morphology was analysed through SEM imaging and it showed that these oxides consists of different particle morphologies and have different particle sizes. Band gap was evaluated from diffuse reflectance spectra and it was found to be 3.24, 3.20 and 3.66 eV respectively for ZnO, TiO2 and SnO2. Among the three AR grade oxides, ZnO exhibited highest photocatalytic activity which is even higher than Degussa P-25 (TiO2) photocatalyst. About 20 % enhancement in the photocatalytic activity of AR grade ZnO was observed when silver metal loaded of on ZnO surface.

scholarly journals Recent Developments of Advanced Ti3+-Self-Doped TiO2 for Efficient Visible-Light-Driven Photocatalysis

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 679 ◽  
Author(s):  
Siyoung Na ◽  
Sohyeon Seo ◽  
Hyoyoung Lee
Keyword(s):  
Visible Light ◽  
Charge Separation ◽  
Defect Density ◽  
Low Cost ◽  
Natural Environments ◽  
Electronic Band ◽  
Environmental Friendliness ◽  
Tio2 Photocatalysts ◽  
Doped Tio2 ◽  
Photogenerated Electrons

Research into the development of efficient semiconductor photocatalytic materials is a promising approach to solving environmental and energy problems worldwide. Among these materials, TiO2 photocatalysts are one of the most commonly used due to their efficient photoactivity, high stability, low cost and environmental friendliness. However, since the UV content of sunlight is less than 5%, the development of visible light-activated TiO2-based photocatalysts is essential to increase the solar energy efficiency. Here, we review recent works on advanced visible light-activated Ti3+-self-doped TiO2 (Ti3+–TiO2) photocatalysts with improved electronic band structures for efficient charge separation. We analyze the different methods used to produce Ti3+–TiO2 photocatalysts, where Ti3+ with a high oxygen defect density can be used for energy production from visible light. We categorize advanced modifications in electronic states of Ti3+–TiO2 by improving their photocatalytic activity. Ti3+–TiO2 photocatalysts with large charge separation and low recombination of photogenerated electrons and holes can be practically applied for energy conversion and advanced oxidation processes in natural environments and deserve significant attention.

scholarly journals One Pot Synthesis of CoTiO3-TiO2 Composite Nanofibers and its Application in Dye Degradation

2019 ◽  
Vol 8 (2) ◽  
pp. 47-56
Author(s):  
M. Shamshi Hassan
Keyword(s):  
Visible Light ◽  
Composite Nanofibers ◽  
Dye Degradation ◽  
Band Gap Energy ◽  
One Pot ◽  
Light Region ◽  
Electrospinning Method ◽  
One Step ◽  
Ft Ir ◽  
The One

CoTiO3-TiO2 composite nanofibrous photocatalysts were synthesized by means of the one-step electrospinning method. The samples were characterized by a range of different methods (XRD, SEM, EPMA, FT-IR, UV-DRS, and TEM). Photocatalytic activity was performed for the degradation of rhodamine 6G under visible light. The results showed that CoTiO3-TiO2 composite photocatalysts were successfully synthesized. The average sizes of the diameters of the composite nanofibers were found to be 300 to 400 nm. The UV–Vis diffuse reflectance spectra of the CoTiO3-TiO2 composite showed an absorption wavelength, in the visible light region, having a band gap energy value of 2.21 eV. The CoTiO3-TiO2 composite showed higher photocatalytic efficiency than that of pristine TiO2; which can be attributed to the heterojunctional interaction between CoTiO3 and TiO2.

Co4I3O24H15⋅3H2O: A new amorphous semiconductor with intrinsical photocatalytic performance in organic dye degradation driven by visible light

2017 ◽  
Vol 10 (02) ◽  
pp. 1750008
Author(s):  
Jiayin Li ◽  
Xinping Ma ◽  
Caixian Zhao ◽  
Datang Li ◽  
Jianting Tang
Keyword(s):  
Visible Light ◽  
Photocatalytic Performance ◽  
Dye Degradation ◽  
Low Cost ◽  
Amorphous Semiconductor ◽  
Organic Dye ◽  
Organic Dye Degradation ◽  
Degussa P25 ◽  
Semiconductor Photocatalyst

Amorphous semiconductor photocatalysts are highly desirable because they are facile and low-cost to prepare in comparison with the crystalline ones. The amorphous semiconductor with photocatalytic activity has been rarely reported. In this work, a new amorphous semiconductor photocatalyst, Co4I3O[Formula: see text]H[Formula: see text][Formula: see text][Formula: see text][Formula: see text]3H2O, was successfully developed. Its microstructure is composed of irregular particles with size of 2–20[Formula: see text][Formula: see text]m. In photocatalytic degradation of rhodamine B (RhB), or methylene blue (MB) dyes driven by visible light, the Co4I3O[Formula: see text]H[Formula: see text][Formula: see text][Formula: see text][Formula: see text]3H2O sample exhibited pronounced activity. Its activity is higher than Degussa P25 (commercial TiO[Formula: see text] in RhB degradation. It was testified that the degradation of RhB is due to the intrinsical photocatalytic role of Co4I3O[Formula: see text]H[Formula: see text][Formula: see text][Formula: see text][Formula: see text]3H2O. The reusability of the Co4I3O[Formula: see text]H[Formula: see text][Formula: see text][Formula: see text][Formula: see text]3H2O photocatalyst was also investigated.

Photo-catalytic Study of Malachite Green Dye Degradation Using Rice Straw Extracted Activated Carbon Supported ZnO Nano-particles

2020 ◽  
Vol 10 (6) ◽  
pp. 849-859
Author(s):  
Radwa A. El-Salamony ◽  
Abeer A. Emam ◽  
Nagwa A. Badawy ◽  
Sara F. El-Morsi
Keyword(s):  
Activated Carbon ◽  
Visible Light ◽  
Rice Straw ◽  
Malachite Green ◽  
Dye Degradation ◽  
Nano Particles ◽  
Oh Radicals ◽  
Impregnation Method ◽  
Photo Degradation ◽  
Malachite Green Dye

Objective: ZnO nanoparticles were synthesized using wet impregnation method, and activated carbon from rice straw (RS) prepared through chemical route. Methods: The nano-composites ZnO-AC series were prepared with different ZnO:AC ratio of 10, 20, 50, and 70% to optimize the zinc oxide nanoparticles used. The obtained composites were characterized by FE-SEM, XRD, SBET, and optical techniques then used for the photo-degradation of Malachite green dye (MG) under visible light. Results: It was found that 10ZnO-AC exhibited excellent visible light photo-catalytic performance. The ·OH radicals’ formation is matching with photo-activity of the prepared composites. The photo-degradation efficiency of MG increased from 63% to 93%, when the 10ZnO-AC photocatalyst amount was increased from 0.5 to 6 g/L. Conclusion: The GC-MS technique was used to analyze the intermediates formed; up to 15 kinds of chemicals were identified as the degradation products.

scholarly journals Enhanced Visible-Light Photocatalytic Performance of SAPO-5-Based g-C3N4 Composite for Rhodamine B (RhB) Degradation

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3948
Author(s):  
Lingfang Qiu ◽  
Zhiwei Zhou ◽  
Mengfan Ma ◽  
Ping Li ◽  
Jinyong Lu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Redox Reactions ◽  
Photocatalytic Performance ◽  
Dye Degradation ◽  
Thermal Polymerization ◽  
Light Illumination ◽  
Electron Hole ◽  
Visible Light Illumination ◽  
Visible Light Photocatalytic

Novel visible-light responded aluminosilicophosphate-5 (SAPO-5)/g-C3N4 composite has been easily constructed by thermal polymerization for the mixture of SAPO-5, NH4Cl, and dicyandiamide. The photocatalytic activity of SAPO-5/g-C3N4 is evaluated by degrading RhB (30 mg/L) under visible light illumination (λ > 420 nm). The effects of SAPO-5 incorporation proportion and initial RhB concentration on the photocatalytic performance have been discussed in detail. The optimized SAPO-5/g-C3N4 composite shows promising degradation efficiency which is 40.6% higher than that of pure g-C3N4. The degradation rate improves from 0.007 min−1 to 0.022 min−1, which is a comparable photocatalytic performance compared with other g-C3N4-based heterojunctions for dye degradation. The migration of photo-induced electrons from g-C3N4 to the Al site of SAPO-5 should promote the photo-induced electron-hole pairs separation rate of g-C3N4 efficiently. Furthermore, the redox reactions for RhB degradation occur on the photo-induced holes in the g-C3N4 and Al sites in SAPO-5, respectively. This achievement not only improves the photocatalytic activity of g-C3N4 efficiently, but also broadens the application of SAPOs in the photocatalytic field.

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