scholarly journals Synthesis and Photoelectrochemical Activity of TiO2 Nanotube Based Free Standing Membrane

2020 ◽  
Vol 32 (11) ◽  
pp. 2739-2742
Author(s):  
Misriyani ◽  
E.S. Kunarti

TiO2 nanotubes (TNTs) were synthesized and modified using the anodization method in a glycerol and ammonium fluoride solution, which was followed by a thermal treatment. The second anodisation was continued by increasing anodizing voltage to deposit a film on the surface of titanium, which resulted in a free standing membrane based on of TNTs. The nanotubes were further characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. The SEM result showed that the layer thickness of free standing membrane based on TNTs increased with an increase in the anodizing voltage; however, at high voltages, this layer was damaged. The XRD and FTIR results indicated the generation of TNT having an anatase crystal phase. The results of test for photoelectrochemical properties showed that the optimal conditions of anodizing voltage was 50 V maintained for 1 h.

2017 ◽  
Vol 748 ◽  
pp. 155-159
Author(s):  
Somkuan Photharin ◽  
Udom Tipparach

We have synthesyzed TiO2 nanotubes by an anodization method. The cathode was titanium (Ti) sheets and anode was platinum (Pt). The electrolytes were mixtures of ethylene glycol (EG), ammonium fluoride (NH4F) and deionized water (DI water). The anodizing voltage was set to 50 V and the process was carried out for 2 h. The titanium foils were anodized at room temperature. Then Ag nanoparticles were loaded in TiO2 nanotube arrays by immersed in 50 ml solutions containing of AgNO3 (1.0, 1.5 and 2.0 mM) for 24 h. The morphology, structure, and optical properties of the prepared nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and and UV-vis spectroscopy (UV-vis) respectively. The structures of TiO2 nanotubes obtained from the nanotube arrays were crystallized by annealing at 450 °C for 2 h before immersed in solution and immersed in solution before crystallized by annealing are similar. When the concentration of silver nitrate (AgNO3) increases, the TiO2 nanotube arrays cracked and are not well arranged.


2014 ◽  
Vol 602-603 ◽  
pp. 947-950
Author(s):  
Zhen Wang ◽  
Hai Yan Chen ◽  
Lin Qiang Gao ◽  
Xin Zou

BiFeO3 nanoparticles were successfully synthesized by a hydrothermal method by a mineralizer (KNO3). Structural characterization was performed by thermal analysis, powder X-ray diffraction (XRD) and scanning electron microscopy (TEM).The results showed that the products were perovskite structure BiFeO3 powders. Optimal conditions for the synthesis of single-phase BiFeO3 ceramics were obtained.


2010 ◽  
Vol 25 (4) ◽  
pp. 658-664 ◽  
Author(s):  
Chang-An Wang ◽  
Keyu Chen ◽  
Yong Huang ◽  
Huirong Le

Layer-structured polypyrrole/montmorillonite (PPy/MMT) naoncomposite films were synthesized by the electrodeposition method. The fabricated free-standing films consist of about 0∼2 wt% Na+-montmorillonite (NMMT). The thickness of films could be controlled by deposition time. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to observe the microstructure of the films. After MMT was introduced into the PPy matrix, the interspace between PPy chains decreased, according to the XRD results. The layered structure of the films was observed from the SEM images. Tensile and nanoindentation test results showed that the mechanical properties of the composite films were improved at low clay loading. The electrical conductivity of the films with 1.2 wt% MMT loading was increased from 3.6 to 51 S/cm, probably because of the restricted growth of PPy chains in the interspace of MMT layers.


Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1419
Author(s):  
Pan Chen ◽  
Yameng Sun ◽  
Lei Yang ◽  
Rui Xu ◽  
Yangyong Luo ◽  
...  

Excessive TiO2 in titanomagnetite concentrates (TC) causes unavoidable problems in subsequent smelting. At present, this issue cannot be addressed using traditional mineral processing technology. Herein, a strategy of metallurgy-beneficiation combination to decrease the TiO2 grade in TC before smelting was proposed. Roasting TC with calcium carbonate (CaCO3) together with magnetic separation proved to be a viable strategy. Under optimal conditions (roasting temperature = 1400 °C, CaCO3 ratio = 20%, and magnetic intensity = 0.18 T), iron and titanium was separated efficiently (Fe grade: 56.6 wt.%; Fe recovery: 70 wt.%; TiO2 grade 3 wt.%; TiO2 removal: 84.1 wt.%). X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy analysis were used to study the mechanisms. The results showed that Ti in TC could react with CaO to form CaTiO3, and thermodynamic calculations provided a relevant theoretical basis. In sum, the metallurgy-beneficiation combination strategy was proven as an effective method to decrease unwanted TiO2 in TC.


2014 ◽  
Vol 602-603 ◽  
pp. 980-984 ◽  
Author(s):  
Jian Ling Zhao ◽  
Qiao Wen Fan ◽  
Ying Juan Mi ◽  
Jing Yang ◽  
Xi Xin Wang

This work presents a novel approach for preparing Cu-loaded TiO2 nanotube arrays through alternating current electrodeposition. The Cu content loaded on the arrays was controlled by changing the concentration of Cu (NO3)2 solution, deposition voltage and time. The surface morphology and crystal structure of Cu-loaded TiO2 nanotube arrays were characterized by scanning electron microscopy (SEM) and the X-ray diffraction (XRD). The effects of Cu content on the photoelectrochemical property were studied in detail. Results show that Cu-loaded TiO2 nanotube arrays have evidently enhanced photoelectrochemical activity. The photocurrent of Cu-loaded TiO2 nanotube arrays prepared in 0.00625 mol/L Cu (NO3)2 solution at 12 V for 20 seconds was 5.7 and 2.3 times as that of unloaded TiO2 nanotube arrays under visible and UV radiation, respectively.


2013 ◽  
Vol 802 ◽  
pp. 104-108 ◽  
Author(s):  
Buagun Samran ◽  
Pacharee Krongkitsiri ◽  
Saichol Pimmongkol ◽  
Sopon Budngam ◽  
Udom Tipparach

TiO2 nanotube arrays were successfully synthesized by the anodization method of Ti foils in electrolyte containing the mixtures of ethylene glycol (EG), ammonium fluoride (0.3 wt % NH4F) and deionized water (2 Vol % H2O). A constant dc power supply at 50 V was used anodization process with different anodizing times. The resultant samples were annealed at 450 °C for 2 h. TiO2 nanotube arrays were studied by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The prepared TiO2 NTs has diameter in 50-200 nm. The minimum of diameter TiO2 nanotube arrays was approximately 50 nm for 1 h of anodization process.


2007 ◽  
Vol 1023 ◽  
Author(s):  
Deepak Dhawan ◽  
Suresh K. Bhargava ◽  
Wojtek Wlodarski ◽  
Kourosh Kalantar-zadeh

AbstractNanoporous Ti (and TiOx) has been formed by anodization of RF sputtered titanium thin films. A solution of 1M (NH4)2SO4 (ammonium sulphate) electrolytes containing 0.5wt% (NH4)F (ammonium fluoride) was used in the anodization process. Different nano and micro structures were obtained. Voltage in a rage of 2 to 10V was employed in the process. It was observed that the magnitude of applied voltage have a significant impact in the formation of different surface morphologies with various nano/micro structures. The anodized titanium thin films were characterised using scanning electron microscopy and X-ray diffraction techniques.


2017 ◽  
Vol 744 ◽  
pp. 453-457
Author(s):  
Somkuan Photharin ◽  
Udom Tipparach

We have synthesized titania nanotubes by an anodization method. The anodization was carried out in a two-electrode configuration bath with Ti sheet as the anode and the Pt as the counter electrode. In this experiment, one face of the Ti foils was exposed to the electrolyte during anodization. The electrolytes were mixtures of ethylene glycol (EG), ammonium fluoride (NH4F) and deionized water (DI water) that contained of Cu and Fe dopants of 0.5 mM. The anodizing voltage was set to 50 V and the anodization was performed at room temperature for 2 h. The nanotubes were crystallized by annealing at 450°C for 2 h. The morphology, structure, and optical properties of the prepared nanotubes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-vis spectroscopy (UV-vis) respectively. The results show that titania nanotubes are anatase phase and the nanotubes are arranged in highly ordered arrays.


2015 ◽  
Vol 1105 ◽  
pp. 220-224 ◽  
Author(s):  
Rinnatha Vongwatthaporn ◽  
Narongsak Kodtharin ◽  
Udom Tipparach

Titania nanotubes (TiO2NTs) photoanodes were synthesized by anodization method. The electrolytes were the mixtures of ethylene glycol (EG), ammonium fluoride (0.3 wt % NH4F) and deionized water (2 Vol % H2O) with different concentrations of dopant Fe (NO3)3∙9H2O. A constant dc power supply at 50 V was used as anodic voltage. The samples were annealed at 450 °C for 2 hours. The resultant products were characterized by Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) to determine their microstructure when TiO2NTs were doped with different amounts of Fe atoms. The diameters of TiO2NTs were about60-120 nm. The highest density of TiO2NTs was obtained when the nanotubes were doped with 0.01 M of Fe.


2019 ◽  
Vol 2 (2) ◽  
pp. 65-76
Author(s):  
Tahereh Poursaberi ◽  
Ali Akbar Miran Beigi

This study investigates an application of zinc metalloporphyrin grafted Fe3O4 nanoparticles as a new adsorbent for removal of sulfate ions from wastewaters. The modification of magnetite nanoparticles was conducted by 3-aminopropyltriethoxysilane followed by zinc (II) porphyrin in order to enhance the removal of sulfate ions. Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) was used to characterize the synthesized nano sorbent. The effect of important experimental factors such as pH, contact time, sorbent dosage and some co-existing anions present in aqueous solutions were investigated. Under optimal conditions (i.e. contact time: 30 min, pH: 6.5 and nanosorbents dosage: 100 mg) for a sulfate sample (50 mL, 50 mgL-1 ) the percentage of the extracted sulfate ions was 94.5%. Regeneration of sulfate adsorbed material could be possible by NaOH solution and the modified magnetic nano sorbent exhibited good reusability.


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