Synthesis and Structure of Titania Nanotubes For Hydrogen Generation

2013 ◽  
Vol 741 ◽  
pp. 84-89 ◽  
Author(s):  
Sangworn Wantawee ◽  
Pacharee Krongkitsiri ◽  
Tippawan Saipin ◽  
Buagun Samran ◽  
Udom Tipparach
Keyword(s):  
Oxalic Acid ◽  
Hydrogen Generation ◽  
Ammonium Fluoride ◽  
Photocurrent Density ◽  
Sodium Sulphate ◽  
Titania Nanotubes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dc Power ◽  
Anodic Voltage

Titania nanotubes (TiO2NTs) working electrodes for hydrogen production by photoelectrocatalytic water splitting were synthesized by means of anodization method. The electrolytes were the mixtures of oxalic acid (H2C2O4), ammonium fluoride (NH4F), and sodium sulphate (VI) (Na2SO4) with different pHs. A constant dc power supply at 20 V was used as anodic voltage. The samples were annealed at 450 °C for 2 hrs. Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) were used to characterized TiO2NTs microstructure. TiO2NTs with diameter of 100 nm were obtained when pH 3 electrolyte consisting of 0.08 M oxalic acid, 0.5 wt% NH4F, and 1.0 wt% Na2SO4was used. Without external applied potential, the maximum photocurrent density was 2.8 mA/cm2under illumination of 100 mW/cm2. Hydrogen was generated at an overall photoconversion efficiency of 3.4 %.

Synthesis and Characterization Anodized Titania Nanotubes for Enhancing Hydrogen Production

2015 ◽  
Vol 749 ◽  
pp. 191-196 ◽  
Author(s):  
Rinnatha Vongwatthaporn ◽  
Udom Tipparach
Keyword(s):  
Ammonium Fluoride ◽  
Photocurrent Density ◽  
Titania Nanotubes ◽  
Applied Potential ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dc Power ◽  
Anodic Voltage ◽  
Tio2 Nts ◽  
Doped Titania

Pure and doped Titania nanotubes (TiO2 NTs) photoanodes were fabricated by means of anodization method. The anodization was carried out in electrolytes prepared by mixing 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 of 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 microstructures when TiO2 NTs were doped with different amounts of Fe atoms. The diameters of TiO2 NTs were about 60-120 nm. The highest density of TiO2 NTs was obtained when the nanotubes were doped with 0.01 M of Fe. The photocatalytic activity was examined without external applied potential. The maximum photocurrent density was 3.0 mA/cm2 under illumination of 100 mW/cm2.

The Synthesis and Structure of Anodized Titania Nanotubes for Energy Conversion Materials

2015 ◽  
Vol 1105 ◽  
pp. 220-224 ◽  
Author(s):  
Rinnatha Vongwatthaporn ◽  
Narongsak Kodtharin ◽  
Udom Tipparach
Keyword(s):  
Power Supply ◽  
Ammonium Fluoride ◽  
Deionized Water ◽  
Titania Nanotubes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dc Power ◽  
Conversion Materials ◽  
Anodic Voltage ◽  
Anodization Method

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.

Fabrication and Characterization of TiO2 Nanotubes for Dye-Sensitized Solar Cells

2015 ◽  
Vol 1131 ◽  
pp. 215-220
Author(s):  
Emmanuel Nyambod Timah ◽  
Buagun Samran ◽  
Udom Tipparach
Keyword(s):  
Solar Cells ◽  
Anatase Phase ◽  
Dye Sensitized Solar Cells ◽  
Ammonium Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dye Sensitized ◽  
Dc Power ◽  
Sensitized Solar Cells

TiO2nanotubes were successfully synthesized by anodization method of Ti foils. The electrolyte was composed of ethylene glycol (EG), ammonium fluoride (0.3%wt NH4F) and de-ionized water (2% vol H2O). A constant DC power supply of 50 V was used during anodization with anodizing times of 1 hour, 2 hours, 4 hours and 6 hours. The samples were annealed at 450 °C for 2 hours. The TiO2nanotubes were studied by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Structural analysis revealed the presence of pure Ti, and the crystalline anatase phase due to transformation of amorphous TiO2after annealing. The morphology of TiO2nanotube sizes showed an increase in tube diameter with anodizing time from approximately 50 nm to 200 nm. However, the efficiency of dye-sensitized solar cells increased with anodizing times up to a maximum of 5.74 % for anodizing time of 4 hours.

Preparation and Microstructure of Titania (TiO2) Nanotube Arrays by Anodization Method

2013 ◽  
Vol 802 ◽  
pp. 104-108 ◽  
Author(s):  
Buagun Samran ◽  
Pacharee Krongkitsiri ◽  
Saichol Pimmongkol ◽  
Sopon Budngam ◽  
Udom Tipparach
Keyword(s):  
Ammonium Fluoride ◽  
Deionized Water ◽  
Nanotube Arrays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Dc Power ◽  
Atomic Force ◽  
Anodization Process ◽  
Anodization Method

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.

Preparation and Properties of Cupper and Iron Doped TiO2 Nanotubes by Anodization Method

2017 ◽  
Vol 744 ◽  
pp. 453-457
Author(s):  
Somkuan Photharin ◽  
Udom Tipparach
Keyword(s):  
Room Temperature ◽  
Anatase Phase ◽  
Ammonium Fluoride ◽  
Deionized Water ◽  
Titania Nanotubes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ordered Arrays ◽  
Vis Spectroscopy ◽  
Anodization Method

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.

scholarly journals Photosensitization of TiO2 Nanotube Arrays with Nanocrystalline Pbs

2019 ◽  
Vol 7 (4.14) ◽  
pp. 560
Author(s):  
Ying-Chin Lim ◽  
Nurul Munirah Hamdan ◽  
Nur Farah Atikah Harun ◽  
Lim Ying Pei
Keyword(s):  
Visible Region ◽  
Precursor Solution ◽  
Solution Concentration ◽  
Photocurrent Density ◽  
Titania Nanotubes ◽  
Photoelectrochemical Cell ◽  
X Ray Diffraction ◽  
Silar Method ◽  
Pbs Nanoparticles ◽  
X Ray

Narrow bandgap lead sulfide (PbS) nanoparticles, which may expand the light absorption range to visible region, have attracted tremendous interest serving as promising sensitizer in coupled semiconductor for photoelectrochemical cell. In this study, PbS were deposited onto titania nanotubes by successive ionic layer adsorption and reaction (SILAR) method. During the SILAR deposition, the growth of PbS onto titania nanotubes (PbS/TNT) had been tuned by tailoring the concentration of the precursor solution. The sample microstructure was characterized using Energy Dispersive X-Ray (EDX), Field Emission Scanning Electron Microscopy (FESEM) and X-Ray Diffraction (XRD). By varying the concentration of precursor solution, size and distribution of PbS nanoparticles could be tuned. Upon growth of PbS onto TNT, all samples showed enhanced photocurrent response ascribed to the changes in microstructure and optical properties of the synthesized samples. At 100 mM solution concentration dipped for 5 SILAR cycles, the sample demonstrated the highest peak photocurrent density of 890 mA/cm2 and a corresponding photoconversion efficiency of 0.55% compared to the as-prepared TNT (36 mA/cm2). The PbS/TNT composite could be considered as an excellent photoelectrode material applied in the solar conversion devices due to its high visible light harvesting capability.    

scholarly journals Photocurrent density and electrical properties of Bi0.5Na0.5TiO3-BaNi0.5Nb0.5O3 ceramics

2021 ◽  
Author(s):  
Mingqiang Zhong ◽  
Qin Feng ◽  
Changlai Yuan ◽  
Xiao Liu ◽  
Baohua Zhu ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Photovoltaic Effect ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Photocurrent Density ◽  
Open Circuit ◽  
Light Conditions ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
X Ray

AbstractIn this work, the (1−x)Bi0.5Na0.5TiO3-xBaNi0.5Nb0.5O3 (BNT-BNN; 0.00 ⩽ x ⩽ 0.20) ceramics were prepared via a high-temperature solid-state method. The crystalline structures, photovoltaic effect, and electrical properties of the ceramics were investigated. According to X-ray diffraction, the system shows a single perovskite structure. The samples show the normal ferroelectric loops. With the increase of BNN content, the remnant polarization (Pr) and coercive field (Ec) decrease gradually. The optical band gap of the samples narrows from 3.10 to 2.27 eV. The conductive species of grains and grain boundaries in the ceramics are ascribed to the double ionized oxygen vacancies. The open-circuit voltage (Voc) of ∼15.7 V and short-circuit current (Jsc) of ∼1450 nA/cm2 are obtained in the 0.95BNT-0.05BNN ceramic under 1 sun illumination (AM1.5G, 100 mW/cm2). A larger Voc of 23 V and a higher Jsc of 5500 nA/cm2 are achieved at the poling field of 60 kV/cm under the same light conditions. The study shows this system has great application prospects in the photovoltaic field.

scholarly journals Synthesis and Characterization of K-Ta Mixed Oxides for Hydrogen Generation in Photocatalysis

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Beata Zielińska ◽  
Ewa Mijowska ◽  
Ryszard J. Kalenczuk
Keyword(s):  
Diffuse Reflectance ◽  
Hydrogen Generation ◽  
Mixed Oxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Photocatalytic Hydrogen Generation ◽  
Irregular Structure ◽  
Transmission Electron

K-Ta mixed oxides photocatalysts have been prepared by impregnation followed by calcination. The influence of the reaction temperature (450°C–900°C) on the phase formation, crystal morphology, and photocatalytic activity in hydrogen generation of the produced materials was investigated. The detailed analysis has revealed that all products exhibit high crystallinity and irregular structure. Moreover, two different crystal structures of potassium tantalates such as KTaO3and K2Ta4O11were obtained. It was also found that the sample composed of KTaO3and traces of unreacted Ta2O5(annealed at 600°C) exhibits the highest activity in the reaction of photocatalytic hydrogen generation. The crystallographic phases, optical and vibronic properties were examined by X-ray diffraction (XRD) and diffuse reflectance (DR) UV-vis and resonance Raman spectroscopic methods, respectively. Morphology and chemical composition of the produced samples were studied using a high-resolution transmission electron microscope (HR-TEM) and an energy dispersive X-ray spectrometer (EDX) as its mode.

scholarly journals Properties and Analysis of Transparency Conducting AZO Films by Using DC Power and RF Power Simultaneous Magnetron Sputtering

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Neng-Fu Shih ◽  
Jin-Zhou Chen ◽  
Yeu-Long Jiang
Keyword(s):  
Incident Light ◽  
Blue Shift ◽  
Light Wavelength ◽  
Rf Power ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dc Power ◽  
Incident Light Wavelength ◽  
Significant Blue Shift ◽  
Sputtering System

DC power and RF power were introduced into the magnetic controlled sputtering system simultaneously to deposit AZO films in order to get an acceptable deposition rate with high quality transparency conducting thin film. The resistivity decreases with the RF power for the as-deposited samples. The resistivity of 6 × 10−4 Ω-cm and 3.5–4.5 × 10−4 Ω-cm is obtained for the as-deposited sample, and for all annealed samples, respectively. The transmittance of the AZO films with higher substrate temperature is generally above 80% for the incident light wavelength within 400–800 nm. The transmittance of the as-deposited samples reveals a clear blue shift phenomenon. The AZO films present (002) oriented preference as can be seen from the X-ray diffraction curves. All AZO films reveal compressive stress. The annealing process improves the electrical property of AZO films. A significant blue shift phenomenon has been found, which may have a great application for electrode in solar cell.

The Effect of Preparation Temperature of Electrolytes on Undoped and Ag-Doped TiO2 Nanotube Structures

2016 ◽  
Vol 860 ◽  
pp. 7-11 ◽  
Author(s):  
Somkuan Photharin ◽  
Buagun Samran ◽  
Rinnatha Vongwatthaporn ◽  
Narongsak Kodtharin ◽  
Ramida Chaiyarat ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electrolyte Solution ◽  
Pure Titanium ◽  
Silver Ions ◽  
Ammonium Fluoride ◽  
Electrolyte Solutions ◽  
Nanotube Arrays ◽  
X Ray Diffraction ◽  
Preparation Temperature ◽  
X Ray

In this work, we present the effect of preparation temperature of electrolytes for fabricating undoped and silver (Ag) doped titanium dioxide (TiO2) nanotubes by the electrochemical anodic oxidation of pure titanium sheets in electrolytes, mixtures of ethylene glycol (EG), ammonium fluoride (NH4F) and deionized water, that contain with different of silver ions. Heat treatment of electrolytes was carried out at 100 °C during preparation process. The morphology and structure of prepared nanotubes were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The structures of TiO2 nanotubes obtained from heat treatment and non-heat treatment of electrolyte solutions and adding silver ions in electrolyte solution are similar. The nanotubes appear in arrays and the diameters of nanotubes were about 92 nm for non-heat treatment electrolyte solution and undoped TiO2 and about 102 nm for heat treatment electrolyte solution and all Ag-doped TiO2 nanotube arrays. When the concentration of silver nitrate (AgNO3) increases, the TiO2 nanotube arrays cracked and are not well arranged.

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