TiO2/Kaolinite Photocatalytic Material of Fe3+ Chemical Doping and Fe2O3 Heat-Banding and its Mechanism Analysis

2010 ◽  
Vol 178 ◽  
pp. 324-329 ◽  
Author(s):  
Chun Hua Bai ◽  
Shui Lin Zheng ◽  
Zhi Ming Sun ◽  
Shao Min Lei ◽  
Jing Ya Gui ◽  
...  

It is very prospective to prepare low-cost TiO2/nonmetallic minerals photocatalytic material, which utilizes sun as light source to treatment environmental problems. TiO2/kaolinite nanocomposite was prepared by sol-gel method, using layered kaolinite as substrate and Ti(OC4H9)4 as precursor. The optimum process conditions were achieved. In addition, photocatalytic material was modified by mean of Fe3+chemical doping and Fe2O3 heat-banding to enhance photocatalytic activity. AZO-dye wastewater containing Direct Blue and Direct Purple was treated by these two kinds of photocatalyst under UV-light and sunlight separately. The results showed that both methods improved material photocatalytic activity in some way and the photocatalytic efficiency was raised significantly in sunlight as well as in UV-light. The photocatalytic effect of Fe2O3 heat-banding was superior to Fe3+chemical doping. The characterization of SEM, TEM, AFM shown that the 1-10nm anatase TiO2 crystal grain was doped on surface of the kaolinite particles which is as like as ‘forest on the ground’. To further analyze the mechanism of the material, XPS was adopted to analyses the chemical composition, elements, valence state.

Author(s):  
Yoshiki Kurokawa ◽  
Dang Trang Nguyen ◽  
KozoK Taguchi

Titanium dioxide (TiO_2) is the most popular photocatalytic material. However, its operation is limited to UV light only. In this paper, we tried to improve the visible light responsiveness of TiO_2 by doping Nickel (Ni) using sol-gel method. By combining Ni-doped TiO_2 powder with commercially available P25 TiO_2 powder to make photocatalytic thin films, significant improvement in photocatalytic activity has been obtained. Furthermore, we also studied the relationship between the surface condition of photocatalytic thin films and their photocatalytic activity. The surface condition was improved by multilayer electrophoresis deposition method. Based on experimental results, by combining 10 - 20 wt% Ni-doped TiO_2 with P25 TiO_2, we could significantly enhance the photocatalytic activity of P25 TiO_2.


2019 ◽  
Vol 36 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Chee Yong Fong ◽  
Sha Shiong Ng ◽  
NurFahana Mohd Amin ◽  
Fong Kwong Yam ◽  
Zainuriah Hassan

Purpose This study aims to explore the applicability of the sol-gel-derived GaN thin films for UV photodetection. Design/methodology/approach GaN-based ultraviolet (UV) photodetector with Pt Schottky contacts was fabricated and its applicability was investigated. The current-voltage (I-V) characteristics of the GaN-based UV photodetector under the dark current and photocurrent were measured. Findings The ideality factors of GaN-based UV photodetector under dark current and photocurrent were 6.93 and 5.62, respectively. While the Schottky barrier heights (SBH) for GaN-based UV photodetector under dark current and photocurrent were 0.35 eV and 0.34 eV, respectively. The contrast ratio and responsivity of this UV photodetector measured at 5 V were found to be 1.36 and 1.68 μA/W, respectively. The photoresponse as a function of time was measured by switching the UV light on and off continuously at different forward biases of 1, 3 and 6 V. The results showed that the fabricated UV photodetector has reasonable stability and repeatability. Originality/value This work demonstrated that GaN-based UV photodetector can be fabricated by using the GaN thin film grown by low-cost and simple sol-gel spin coating method.


RSC Advances ◽  
2018 ◽  
Vol 8 (13) ◽  
pp. 6752-6758 ◽  
Author(s):  
Yuanyang Wang ◽  
Yinghua Zhang ◽  
Haiqiang Lu ◽  
Yanxin Chen ◽  
Zhenmin Liu ◽  
...  

Two new types of N-doped ZrO2 photocatalysts ZON and AZON have been synthesized using ethylenediamine as the nitrogen source by a facile and low-cost sol–gel method.


2018 ◽  
Vol 762 ◽  
pp. 278-282
Author(s):  
Anzelms Zukuls ◽  
Gundars Mežinskis ◽  
Aigars Reinis ◽  
Ingus Skadins ◽  
Juta Kroica ◽  
...  

Prepared and heat-treated sol-gel ZnO-TiO2 coatings onto microscope glass slides were characterised by atomic force microscopy (AFM), scanning electron microscopy (SEM), as well as absorption spectra of light has been obtained. Thermally treated xerogels were characterised by X-ray diffraction (XRD). As well as their photocatalytic activity using methyl orange (MO) and observing the colour changes over the time in visible light (VIS) and ultra violet (UV) light has been determined. The influence of ZnO concentration on morphology, photocatalytic activity and antibacterial properties of coatings was analysed. The growth of S. epidermidis on the surface of the samples was inhibited due to photocatalytic properties of coatings.


2018 ◽  
Vol 762 ◽  
pp. 408-412
Author(s):  
Raivis Eglītis ◽  
Gundars Mežinskis

In this work two different hydrosols were used to impregnate a commercially available cotton fabric with anatase nanoparticles to give it photocatalytic activity. To increase the activity, different pre-treatment methods were applied. The nanoparticle size was determined using dynamic light scattering and x-ray diffraction and the fabrics were examined using scanning electron microscopy. Photocatalytic activity was measured using the degradation of methyl-orange while irradiating the samples with UV light. The synthesis method allowed to produce anatase with an average particle size of 32 to 37 nm depending on the synthesis method used.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
V. L. Chandraboss ◽  
B. Karthikeyan ◽  
J. Kamalakkannan ◽  
S. Prabha ◽  
S. Senthilvelan

The TiO2/SiO2 and ZnO/SiO2 composite films were prepared by sol-gel dip coating method. The surface morphology and crystal structure of thin films were characterized by means of scanning electron microscopy (SEM) with elementary dispersive X-ray analysis (EDX) and X-ray diffractometer (XRD). Optical properties of films have been investigated using ultraviolet and visible spectroscopy (UV-visible spectroscopy). The photocatalytic activity was established by testing the degradation and decolorization of methyl green (MG) from aqueous solution with artificial UV-light.


2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Manoj Pudukudy ◽  
Zahira Yaakob

AbstractMesoporous spinel Co3O4 nanosheets were synthesised via a simple sol-gel route using the Pluronic P123 triblock copolymer as the stabilising agent. Their structural, morphological, and textural properties were characterised. FTIR spectrum revealed the formation of cobalt oxide without any surface adsorbed impurities. Face centered cubic phase of spinel Co3O4 with the mean crystalline size of 26 nm was assigned by the X-ray diffraction analysis without the formation of other phases. Porous nanosheets and cave-like morphologies were identified from the scanning electron microscopy (SEM) images. Highly agglomerated more or less spherical particles with well separated lattice fringes, representing the oriented growth of nanocrystals, were noticed on the transmission electron microscopy photographs. Surface area analysis revealed that the spinel has high surface area of about 25 m2 g−1 with monomodal mesoporosity. The average pore size distribution was found to be about 15.8 nm. The as-prepared spinel photocatalyst showed a mild photocatalytic activity in the degradation of methylene blue (2.5 mg L−1) under UV light irradiation with air as the oxidising agent. Photocatalytic activity of the as-prepared reusable Co3O4 was found to be higher than that of the commercial spinel powder.


2013 ◽  
Vol 829 ◽  
pp. 902-906 ◽  
Author(s):  
Mohammad Derakhshani ◽  
Hossein Abdizadeh ◽  
Mohammad Reza Golobostanfard

Recently photocatalytic materials have been used in variety of industrial applications. TiO2 is the only suitable photocatalytic material for industrial usage due to its benefits such as non-toxicity, stability, and low cost. TiO2 nanoparticles were successfully synthesized from titanium alkoxide precursor by sol-gel method. Effects of nitrogen doping on the microstructure and phase evolution of the TiO2 nanoparticles were investigated. The X-ray diffraction results of doped samples confirm the presence of anatase as the only crystalline phase. The addition of nitrogen in titania matrix leads to disappearance of rutile traces. The scanning electron microscopy show that TiO2 nanoparticle size decreases by increasing nitrogen doping. Furthermore, DSC-TG results reveal that the crystallization temperature of doped sample shifts to higher temperatures of about 100 °C.


2016 ◽  
Vol 680 ◽  
pp. 193-197
Author(s):  
San Ti Yi ◽  
Si Qin Zhao

TiO2, 1%La/TiO2, 1%Ce/TiO2 and a series of Laand Ce co-doped TiO2 photocatalysts were prepared by sol-gel method. Using sol-gel method combine with hydrothermal method prepared rare earth La, Ce and nitrogen co-doped TiO2 photocatalysts. The microstructure, spectroscopy performance and ion doped form of prepared samples were characterized by X-ray powder diffraction (XRD), UV-Vis diffuse reflectance spectroscopy techniques and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of doped TiO2 were examined by measuring the photodegradation of methyl orange. The results showed that the products were all anatase TiO2 nano powder, doping Laor Cehinder the growth of TiO2 particle, further more, doping Laand Cetogether hinder the growth of TiO2 particle more effective, doping N broaden the light response range of TiO2 photocatalyst. At the same time, the photocatalytic activity results indicated that the prepared samples showed superior UV light photocatalytic activity, the sample 1% (La:Ce,9:1)-N/TiO2 showed the highest UV-vis photocatalytic activity.


2011 ◽  
Vol 391-392 ◽  
pp. 219-224
Author(s):  
Jin Huan Li ◽  
Hong Bo Fang ◽  
Wei Wang ◽  
Gui Fan Liu ◽  
Shao Dong Zhang

Nanocrystals with different Eu3+ doping levels (%) were prepared by sol-gel and hydrothermal synthetic method using titanium tetraisopropoxide (TTIP) as titanium source. The products exhibited anatase phase structure, mesoporosity, and interesting surface compositions with three oxygen species and two titanium species. The crystallite sizes, crystal form, surface shape, composition and optical property of catalysts were characterized by X-ray diffraction patterns, UV-Vis diffuse reflectance spectroscopy, XPS and inductively coupled plasma atomic emission spectroscopy. The products were used as the photocatalysts to degrade a partially hydrolysis polyacrylamide (HPAM) under UV-light irradiation, a very useful polymer in oil recovery. For comparison, Degussa P25 and as-prepared pure TiO2 were also tested under the same conditions. The enhanced photocatalytic activity was obtained on as-prepared Eu3+ composites, and the reasons were explained.


Sign in / Sign up

Export Citation Format

Share Document