scholarly journals Synthesis of Titanium Dioxide Nanotubes with Different N-Containing Ligands via Hydrothermal Method

2021 ◽  
Vol 6 (2) ◽  
pp. 67-73
Author(s):  
Cheng Yee Leong ◽  
Ye Shen Lo ◽  
Pei Wen Koh ◽  
Siew Ling Lee

Titanium dioxide (TiO2) nanotubes (TNT) were successfully synthesized using different N-containing ligands via hydrothermal method. Methylamine, ethylenediamine and diethylenetriamine with different Ti/ligand molar ratios (1:1, 1:3, 1:5 and 1:8) were prepared. As-synthesized TiO2 without N-containing ligands were also prepared for comparison purpose. The X-Ray Diffraction patterns confirmed the presence of anatase phase of TiO2 in all the synthesized samples whereas the presence of sodium titanate was only detected in the samples containing N-containing ligands. The Transmission Electron Microscopy images also showed that the N-containing ligands promoted the formation of nanotubes in the anatase TiO2. Based on the Tauc Plot, the band gap energy of anatase TiO2 was shifted with the addition of methylamine, ethylenediamine and diethylenetriamine. The photoluminescence spectra also showed that with the addition of sufficient amount of N-containing ligands, the intensity of photoluminescence spectrum decreased, suggesting formation of more nanotube and reduction of electron hole recombination rate. The photocatalytic performance of all synthesized samples was determined through photodegradation of Congo red under UV light for 6 hours. The results suggested that among the synthesized materials, the sample which contained diethylenetriamine with molar ratio of 5 gave the highest photocatalytic activity of 76.71% which could be attributed to successful formation of nanotube, its higher surface rate reaction and low electron hole recombination. Diethylenetriamine showed higher efficiency in assisting the formation of TiO2 nanotubes compared to methylamine and ethylenediamine.

Author(s):  
Nor Shuhada Alim ◽  
Hendrik O. Lintang ◽  
Leny Yuliati

Reduced graphene oxide (rGO) has been one of the most investigated carbon based materials due to its great electronic conductivity that make it able to accept and transport electron easily. In order to study the effect of rGO, anatase titanium dioxide-reduced graphene oxide (TiO2-rGO) composite was prepared by UV-assisted photocatalytic reduction method using the anatase TiO2 as a photocatalyst and various different loadings of graphene oxide (GO). The characterizations of the prepared samples were investigated by X-ray diffractometer (XRD), Fourier transform infrared (FTIR), and fluorescence spectroscopies. The XRD patterns and FTIR spectra confirmed that all the TiO2-rGO composites samples were successfully synthesized without disrupting the structure of the anatase TiO2. Fluorescence spectroscopy revealed the role of the rGO to reduce the electron-hole recombination on the anatase TiO2. In the photocatalytic removal of phenol, all the TiO2-rGO composites showed better photocatalytic activities than the bare anatase TiO2 under UV light irradiation. The activity of the anatase TiO2 was enhanced by more than four times with the addition of the GO with the optimum amount (3 wt%). It was proposed that the good photocatalytic performance obtained on the composites were caused by the successful suppression of electron-hole recombination by the rGO on the TiO2.


2018 ◽  
Vol 80 (2) ◽  
Author(s):  
Klinsmann Cheong Lee Khang ◽  
Mohd Hayrie Mohd Hatta ◽  
Siew Ling Lee ◽  
Leny Yuliati

A series of mesoporous ZnO/TiO2 composites were successfully synthesized using cetyltrimethylammonium bromide surfactant. The composites of different Zn:Ti molar ratios (0.5:1, 0.75:1, and 1:1) were prepared by impregnating ZnO onto mesoporous TiO2. XRD results verified co-existence of both anatase TiO2 and hexagonal wurtzite ZnO in the ZnO/TiO2 composites. Based on the Tauc plots, all the composites showed almost the same band gap energy of approximately 3.21 eV. The fourier transform infrared spectroscopy results successful covering of ZnO on the surface of the TiO2 as the hydrophilicity property of TiO2 decreased remarkably with the loading of ZnO in the composites. N2 adsorption-desorption isotherms of the samples exhibited type-IV isotherm with a hysteresis loop. The Barrett-Joyner-Halenda pore size distribution revealed that the average pore size of the composites was around 3.6 nm, indicating the formation of mesopores dominantly in the samples. The photocatalytic removal of phenol over the samples under UV light irradiation after 3 h decreased in the order: ZnO/TiO2 composites > anatase TiO2 (with surfactant) > anatase TiO2 (without surfactant) > ZnO. The composite with Zn:Ti molar ratio of 0.75:1 has achieved the highest photocatalytic activity of 36.5% in the removal of phenol under UV light irradiation for 3 h.


2020 ◽  
Vol 8 (47) ◽  
pp. 25235-25244
Author(s):  
Yating Yang ◽  
Zhaosheng Zhang ◽  
Wei-Hai Fang ◽  
Sebastian Fernandez-Alberti ◽  
Run Long

TiO2 doping with nitrogen greatly suppresses nonradiative electron-hole recombination and enhances photocatalytic activity.


2014 ◽  
Vol 40 (7) ◽  
pp. 9241-9247 ◽  
Author(s):  
Deaw Aphairaj ◽  
Thanakorn Wirunmongkol ◽  
Sutham Niyomwas ◽  
Sorapong Pavasupree ◽  
Pichet Limsuwan

2013 ◽  
Vol 641-642 ◽  
pp. 11-17 ◽  
Author(s):  
Zhi Peng Meng ◽  
Fu Xin Zhong ◽  
Dan Yu Wang ◽  
Zhong Ming Zhang ◽  
Hua Ying Li ◽  
...  

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.


Author(s):  
E. Romero Torres ◽  
M. Gutiérrez Arzaluz ◽  
V Mugica Alvarez ◽  
L. González Reyes ◽  
M. Torres Rodríguez ◽  
...  

The photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) using a Au/TiO2 catalyst and ultraviolet (UV) light energy source (9 mW/cm2) discussed. Gold nanoparticles were synthesized by controlled urea reduction and deposited on titanium dioxide (TiO2) by the deposition-precipitation method. The average size of the nanoparticles was 6-8 nm. X-ray diffraction (XRD) characterization confirmed that TiO2 was present in the anatase phase, whereas the presence and particle size of gold were determined by transmission electron microscopy (TEM). The results of the degradation showed that the activity of TiO2 was improved when Au nanoparticles were present on the surface. The reactions were performed at atmospheric pressure and room temperature.


NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050100
Author(s):  
Fengxia Zhang ◽  
Haining Liu ◽  
Tianyi Jiang ◽  
Yanyan Zhu ◽  
Xiushen Ye ◽  
...  

The construction of organic–inorganic hybrids is one of the important ways to improve performances of photocatalysts. In this study, perylene tetracarboxylic tetra (n-butyl) ester loaded titanium dioxide (PTTE-B/TiO2) nanocomposite was successfully synthesized by hydrothermal method. The catalyst was characterized by XRD, DRS, XPS, Photoluminescence spectroscopy (PL) and BET. FT-IR and XPS analyses revealed the presence of Ti[Formula: see text]O bond in the interfaces between TiO2 and PTTE-B. The photoluminescence intensity of PTTE-B/TiO2 was decreased compared to TiO2, which indicated a suppression of electron–hole recombination by the loaded PTTE-B nanoparticles. The photocatalytic activity of PTTE-B/TiO2 nanocomposite for degradation of EBT using visible light was higher than that of prepared TiO2 or TiO2-P25. The detection of radical scavengers confirmed that h[Formula: see text] and [Formula: see text] were the main active substances for Eriochrome Black T (EBT, an azo dye) degradation. The Ti[Formula: see text]O bond acted as a short and fast channel for photogenerated charge carriers to migrate from PTTE-B to TiO2. Furthermore, PTTE-B/TiO2 was found to be stable and reusable.


2007 ◽  
Vol 544-545 ◽  
pp. 71-74
Author(s):  
Jun Ho Kim ◽  
Kwon Taek Lim ◽  
Gun Dae Lee ◽  
Seong Soo Park ◽  
Seong Soo Hong

TiO2 nanoparticles were prepared using the hydrolysis of titanium tetraisopropoxide (TTIP) using TENOH as a peptizing agent in the hydrothermal method. The physical properties of prepared nanosized TiO2 particles were investigated. The photocatalytic degradation of orange II has been studied using a batch reactor in the presence of UV light. The crystallite size of the anatase phase is increased from 15 to 30 nm as the molar ratio of TENOH/TTIP increases from 0.1 to 1.0. The titania particle prepared at TENOH/TTIP molar ratio=0.1 shows the highest activity on the photocatalytic decomposition of orange II and the photocatalytic activity decreases according to an increase in TENOH/TTIP molar ratio. In addition, the titania particles prepared at 160oC shows the highest activity on the photocatalytic decomposition of orange II


2010 ◽  
Vol 156-157 ◽  
pp. 1725-1729
Author(s):  
Yan Wei Dou ◽  
Xue Feng ◽  
Chao Yin

We review the fabrication and properties of highly ordered TiO2 nanotube arrays made by anodic oxidation of titanium in fluoride-based electrolytes. The N-doped TiO2 nanotubes were prepared by changing the composition of electrolyte. TiO2 nanotubes and N-doped TiO2 nanotubes characterized by various analytical methods, such as scanning electron microscope (SEM) and X-ray photoelectron emission spectroscopy (XPS). The photocatalytic efficiency was evaluated by the photodegradation of Methyl orange solution under UV irradiation. It has been confirmed that the recombination rate of electron-hole pairs declined significantly. The higher visible light activity is due to the codoping of nitrogen.


Dermato ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 2-17
Author(s):  
Bruna G. Chiari-Andréo ◽  
Joana Marto ◽  
Andreia Ascenso ◽  
Carlos Carneiro ◽  
Laura Rodríguez ◽  
...  

(1) Background: Titanium dioxide (TiO2) consists of three polymorphs, including anatase, rutile and brookite. This work aimed to elucidate the influence of rutile and anatase forms in the performance of sunscreens formulated with green coffee oil (GCO) from coffee beans discarded in the agri-food industry. (2) Methods: TiO2 particles were characterized in terms of size and wettability. The sunscreens formulated with GCO were characterized regarding the droplet size, rheology, texture profile analysis (TPA), in vitro Sun Protection Factor and Water Resistance Retention. Topical delivery and permeation studies were performed to confirm caffeine release and skin penetration. (3) Results: Particle size distributions of rutile and anatase TiO2 particles were similar, however, smaller droplets as well as decreased viscosity and increased thixotropy were obtained for anatase TiO2 and GCO formulation compared to rutile form formulations. Notwithstanding, all formulations exhibited linear viscoelastic behavior. Regarding the TPA, a wide range of mechanical properties improved mainly by GCO rather than TiO2 form has been demonstrated. The influence of TiO2 form on UV protection was better evidenced in absence of GCO. The sunscreen formulations containing GCO presented a favorable topical delivery as confirmed by caffeine release and permeation. (4) Conclusions: Both TiO2 forms combined with GCO provided suitable properties including an effective ultraviolet (UV)-light protection.


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