scholarly journals TiO2 and Au-TiO2 Nanomaterials for Rapid Photocatalytic Degradation of Antibiotic Residues in Aquaculture Wastewater

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2434 ◽  
Author(s):  
Tho Chau Minh Vinh Do ◽  
Duy Quoc Nguyen ◽  
Kien Trung Nguyen ◽  
Phuoc Huu Le
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Synergistic Effects ◽  
Chemical Reduction ◽  
Anatase Phase ◽  
Au Nanoparticle ◽  
Nanotube Arrays ◽  
Antibiotic Residues ◽  
Au Nps ◽  
Aquaculture Wastewater

Antibiotic residues in aquaculture wastewater are considered as an emerging environmental problem, as they are not efficiently removed in wastewater treatment plants. To address this issue, we fabricated TiO2 nanotube arrays (TNAs), TiO2 nanowires on nanotube arrays (TNWs/TNAs), Au nanoparticle (NP)-decorated-TNAs, and TNWs/TNAs, which were applied for assessing the photocatalytic degradation of eight antibiotics, simultaneously. The TNAs and TNWs/TNAs were synthesized by anodization using an aqueous NH4F/ethylene glycol solution. Au NPs were synthesized by chemical reduction method, and used to decorate on TNAs and TNWs/TNAs. All the TiO2 nanostructures exhibited anatase phase and well-defined morphology. The photocatalytic performance of TNAs, TNWs/TNAs, Au-TNAs and Au-TNWs/TNAs was studied by monitoring the degradation of amoxicillin, ampicillin, doxycycline, oxytetracycline, lincomycin, vancomycin, sulfamethazine, and sulfamethoxazole under ultraviolet (UV)-visible (VIS), or VIS illumination by LC-MS/MS method. All the four kinds of nanomaterials degraded the antibiotics effectively and rapidly, in which most antibiotics were removed completely after 20 min treatment. The Au-TNWs/TNAs exhibited the highest photocatalytic activity in degradation of the eight antibiotics. For example, reaction rate constants of Au-TNWs/TNAs for degradation of lincomycin reached 0.26 min−1 and 0.096 min−1 under UV-VIS and VIS irradiation, respectively; and they were even higher for the other antibiotics. The excellent photocatalytic activity of Au-TNWs/TNAs was attributed to the synergistic effects of: (1) The larger surface area of TNWs/TNAs as compared to TNAs, and (2) surface plasmonic effect in Au NPs to enhance the visible light harvesting.

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.

scholarly journals One-step electrosynthesis of visible light responsive double-walled alloy titanium dioxide nanotube arrays for use in photocatalytic degradation of dibutyl phthalate

RSC Advances ◽  
2020 ◽  
Vol 10 (36) ◽  
pp. 21238-21247 ◽  
Author(s):  
Yuan Wang ◽  
Xueke Zhang ◽  
Suzhen You ◽  
Yun Hu
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Active Sites ◽  
Dibutyl Phthalate ◽  
Nanotube Arrays ◽  
One Step ◽  
Titanium Dioxide Nanotube Arrays ◽  
Alloy Titanium

The double-walled alloy titanium dioxide nanotube arrays (DW-ATNTAs) with special porous inner walls exhibit superior photocatalytic activity under visible light for rich porous inner wall provided sufficient vacancy for adsorption and active sites.

The Photocatalytic Properties of Br-Doped Titania Nanotube Arrays and its Application in Degradation of Sugar Wastewater

2013 ◽  
Vol 641-642 ◽  
pp. 11-17 ◽  
Author(s):  
Zhi Peng Meng ◽  
Fu Xin Zhong ◽  
Dan Yu Wang ◽  
Zhong Ming Zhang ◽  
Hua Ying Li ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Uv Light ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Photocatalytic Properties ◽  
Nanotube Arrays ◽  
Illumination Time ◽  
Novel Approach ◽  
Titanium Dioxide Nanotube Arrays

This paper presents a novel approach for preparing titanium dioxide nanotube arrays (TNTs) loaded with highly dispersed Br through an ultrasound aided photochemical route. The content of Br doped on the arrays was controlled by changing the concentration of NaBr and the ultrasound time. The Br doped TiO2nanotube arrays were characterized by SEM, XRD and UV–Vis spectrum. Doping the bromine did not basically affect the morphology of the surface of the TNTs, but part of the anatase phase transformed into rutile phase, which led to the formation of the mixed crystal and increased the photocatalytic activity. The results showed that Br doping significantly enhanced the photocatalytic degradation rate of titanium dioxide nanotube arrays under UV-light irradiation. The main factors which affected photocatalytic degradation of sugar wastewater were the illumination time and pH. The results showed that the longer the exposure time was, the initial pH of wastewater was more favorable to photocatalytic degradation of the sugar wastewater for the Br-TiO2nanotube arrays, and compared to undoped TiO2nanotube arrays Br doped TiO2nanotube arrays had better photocatalytic properties.

Preparation and Characterization of Cu Loaded TiO2 Nanotube Arrays and their Photocatalytic Activity

2011 ◽  
Vol 364 ◽  
pp. 377-381 ◽  
Author(s):  
Syazwani Mohd Zaki ◽  
Srimala Sreekantan
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Anatase Phase ◽  
Average Diameter ◽  
Photoelectron Spectra ◽  
Nanotube Arrays ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
Wet Impregnation ◽  
X Ray

This paper described the preparation of Cu loaded TiO₂ nanotube arrays. Firstly, TiO₂ nanotube arrays were formed by anodization. Afterwards, the formed nanotube arrays were incorporated with Cu by wet impregnation method. The soaking time and concentration were varied to obtain an optimum set of parameter for Cu incorporation in TiO₂ nanotubes. After anodization, all samples were annealed at 400°C for 4 hours to obtain anatase phase. The nanotube arrays were characterized by field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD) and x-ray photoelectron spectra (XPS). An average diameter 63.02 nm and length 12.15µm were obtained for TiO₂ nanotubes. The photocatalytic activity of these nanotubes were investigated with methyl orange (MO) and the TiO₂ nanotube prepared in 0.01M of Cu (NO₃)₂ solution within 3 hours demonstrates the highest photocatalytic activity with 83.6% degradation of methyl orange. Keywords: copper doping, wet impregnation, photocatalytic activity

Enhanced photocatalytic activity of Bi2WO6 for the degradation of TC by synergistic effects between amorphous Ti and Ni as hole–electron cocatalysts

2020 ◽  
Vol 44 (26) ◽  
pp. 10833-10839
Author(s):  
Chenjing Sun ◽  
Rui Wang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Synergistic Effects

The possible mechanism of photocatalytic degradation of TC by Ni/Ti-Bi2WO6 under visible light.

Visible light assisted photocatalytic degradation of methylene blue dye and mixture of dyes using ZrO2-TiO2 nanocomposites

2020 ◽  
Vol 16 ◽  
Author(s):  
Radhakrishna S. Sutar ◽  
Rani P. Barkul ◽  
Meghshyam K. Patil
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Anatase Phase ◽  
Physicochemical Characterization ◽  
Catalytic Efficiency ◽  
Catalyst Loading ◽  
Blue Dye ◽  
Methylene Blue Dye

Background: Different photocatalysts such as TiO2, ZnO, WO3 have been used for degradation of organic pollutants. However, these materials having some limitations, which has been affected the catalytic efficiency in the various transformations. The composites of these materials with other oxide can produce better results by tuning structural as well as optoelectrical properties. The composite of TiO2 with ZrO2 has attracted attention due to their use in different areas as ZrO2 and TiO2 have similar physicochemical features. Methods: This research contain the preparation of ZrO2-TiO2 nanocomposites by hydrothermal method and analysis of photocatalytic activity for degradation of methylene blue and mixture of dyes under visible light irradiation. Results: Physicochemical characterization of ZrO2-TiO2 nanocomposites has been studied by using different techniques. Prepared catalysts has shown anatase phase of TiO2 and tetragonal phase of ZrO2. XRD, FESEM and HRTEM have supported the nanocrystalline nature of the composites. The photocatalytic activity of composites and bare TiO2 samples were demonstrated for the degradation of methylene blue dye. Enhanced activity has been shown by composite having Ti:Zr 3:1 molar proportion i.e., Ti3Zr. Effect of concentration of methylene blue, pH of solution, catalyst loading has been studied by using Ti3Zr. Also, degradation of mixture of three dyes namely methylene blue, rhodamine B and methyl orange has been studied. Conclusion: In summary, prepared zro2-tio2 composites found to be nanocrystalline and visible light active. these catalysts has shown activity for photocatalytic degradation of methylene blue and mixture of dyes.

Preparation of Well-Ordered TiO2 Nanotube Arrays by Electrochemical Anodization of Titanium Foil in Neutral Electrolytes

2011 ◽  
Vol 233-235 ◽  
pp. 2047-2050
Author(s):  
Chao Wang ◽  
Da Chen ◽  
Shu Liu ◽  
Xia Ni Huang ◽  
Yue Xiang Huang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Photocatalytic Activity ◽  
Solar Energy ◽  
Band Gap ◽  
High Performance ◽  
Diffuse Reflectance ◽  
Anatase Phase ◽  
Titanium Foil ◽  
Electrochemical Anodization ◽  
Nanotube Arrays

To obtain high performance TiO2nanotube arrays (TNAs)-based material is interesting because of its wide applications in photocatalysis field such as solar energy conversion, photocatalysis and sensors. In the present work, the well-ordered TNAs were prepared by electrochemical anodization of titanium foil in the SO42−/F−based electrolyte under 20 V for 2 h during which the Ti foil and Pt wire were used as anode and cathode, respectively. The FESEM results showed that the as-obtained TNAs were well-aligned on Ti substrate with ~ 1.5 μm in length and ~ 100 nm pore in diameter. The XRD results indicated that the as-formed TNAs was in the form of amorphous and could be transformed into crystalline anatase phase under the heat treatment at 450 °C. Meanwhile, the UV-vis diffuse reflectance spectra demonstrated that the band-gap of the obtained TNAs was narrower than the commercial TiO2nanoparticles, indicating a better photocatalytic activity of the as-prepared TNAs over the commercial TiO2nanoparticles.

Hydrothermal Preparation and Photocatalytic Activity of Different Morphology Titania

2012 ◽  
Vol 510 ◽  
pp. 569-574 ◽  
Author(s):  
Huai Yuan Wang ◽  
Yan Ji Zhu ◽  
Zhen Yu ◽  
You Zhuang Zhu ◽  
Ying Chen
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Specific Surface ◽  
Photocatalytic Degradation ◽  
Anatase Phase ◽  
Tetrabutyl Titanate ◽  
Hydrothermal Preparation ◽  
Surface Areas ◽  
Template Free ◽  
Specific Surface Areas

TiO2 samples with various shapes like flake, nanofiber and large grain were synthesized by template-free hydrothermal method with rutile TiO2 or tetrabutyl titanate (Ti (OC4H9)4, TBOT) as precursor. Photocatalytic degradation performances were investigated by using methyl orange (MO) as modeling pollutant. The results shown that pure mesoporous anatase TiO2-Grain showed the highest photocatalytic activity (3.7 times higher than P25), which is due to a combinative effect of anatase phase and high specific surface areas. The bi-phase flaky TiO2 also have higher activity than P25. While, nanofiber with TiO2(B) phase has the lowest photocatalytic activity. The large sized TiO2 grain can be separated and recycled easily after reaction.

scholarly journals Photocatalytic Degradation of Rhodamine B and Methylene Orange Using TiO2-ZrO2 as Nanocomposite

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1035
Author(s):  
Víctor Ruíz-Santoyo ◽  
Virginia F. Marañon-Ruiz ◽  
Rafael Romero-Toledo ◽  
Oscar Arturo González Vargas ◽  
Alejandro Pérez-Larios
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
Anatase Phase ◽  
Structural Defects ◽  
Kinetics Parameters ◽  
Doped Tio2 ◽  
X Ray

The present research reports the synthesis of ZrO2-doped TiO2 photocatalysts at different ZrO2 contents (1, 3 and 5% wt.) synthesized by the sol–gel method. The samples were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction, attenuated total reflectance-Fourier transform infrared, ultraviolet–visible, X-ray photoelectron spectroscopy and N2 adsorption–desorption analysis. The photocatalytic activity of the ZrO2-doped TiO2 was investigated against the dyes methyl orange and rhodamine B through mineralization studies. The ZrO2-doped TiO2 samples presented a semiglobular-ovoid agglomerate shape around 500–800 nm. The samples presented high crystallinity of the TiO2 anatase phase, XPS suggested the formation of Zr–O–Ti bonds and the samples were classified as mesoporous materials with slight changes in the optical features in comparison with pure TiO2. Our study shows that the ZrO2-doped TiO2 composites exhibited a higher photocatalytic activity than just utilizing the synthetized TiO2 and a commercial P25. The different degradation behaviors are attributed to differences in the textural properties, and to the different optical absorptions of the samples due to structural defects created by the level of doping of Zr4+ ions into the TiO2 lattice. Reaction kinetics parameters were calculated by the Langmuir–Hinshelwood model, and a third run cycle of the ZrO2-doped TiO2 at 1% wt. achieved a photocatalytic degradation of 78.1 and 75.5% for RhB and MO, respectively.

scholarly journals Enhanced Photocatalytic Performance of Nitrogen-Doped TiO2 Nanotube Arrays Using a Simple Annealing Process

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 618 ◽  
Author(s):  
Phuoc Le ◽  
Le Hieu ◽  
Tu-Ngoc Lam ◽  
Nguyen Hang ◽  
Nguyen Truong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Performance ◽  
Synergistic Effects ◽  
Annealing Process ◽  
Tio2 Nanotube Arrays ◽  
Tio2 Nanotube ◽  
Nanotube Arrays ◽  
Doped Tio2 ◽  
Nitrogen Doped ◽  
N Doping

Nitrogen-doped TiO2 nanotube arrays (N-TNAs) were successfully fabricated by a simple thermal annealing process in ambient N2 gas at 450 °C for 3 h. TNAs with modified morphologies were prepared by a two-step anodization using an aqueous NH4F/ethylene glycol solution. The N-doping concentration (0–9.47 at %) can be varied by controlling N2 gas flow rates between 0 and 500 cc/min during the annealing process. Photocatalytic performance of as-prepared TNAs and N-TNAs was studied by monitoring the methylene blue degradation under visible light (λ ≥ 400 nm) illumination at 120 mW·cm−2. N-TNAs exhibited appreciably enhanced photocatalytic activity as compared to TNAs. The reaction rate constant for N-TNAs (9.47 at % N) reached 0.26 h−1, which was a 125% improvement over that of TNAs (0.115 h−1). The significant enhanced photocatalytic activity of N-TNAs over TNAs is attributed to the synergistic effects of (1) a reduced band gap associated with the introduction of N-doping states to serve as carrier reservoir, and (2) a reduced electron‒hole recombination rate.

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