scholarly journals Degradation of Typical Indoor Air Pollutants Using Fe-Doped TiO2Thin Film under Daylight Illumination

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Shuaijie Wang ◽  
Hao Yu ◽  
Xingxing Cheng
Keyword(s):  
Thin Film ◽  
Sol Gel ◽  
Visible Region ◽  
Preparation Condition ◽  
Solar Light ◽  
Photocatalytic Reaction ◽  
X Ray Diffraction ◽  
Vis Spectroscopy ◽  
Doped Titania ◽  
Indoor Air Pollutants

A type of iron-doped titania thin film was prepared by means of sol-gel method to degrade indoor formaldehyde (HCHO), ammonia (NH3), and benzene (C6H6) under sunlight. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy, and energy dispersive spetra (EDS). The results showed that the iron was doped in the TiO2photocatalyst successfully. The absorption edge of doped TiO2had red shifts and the doped TiO2had a stronger absorption than the pure TiO2in the visible region. Fe-doped TiO2thin film prepared with the optimal preparation condition could remove indoor HCHO, NH3and C6H6effectively under solar light irradiation. The removal percentage of HCHO, NH3or C6H6after 9 h photocatalytic reaction under solar light reached 55%, 53.1%, and 37.5%, respectively, when they existed in the air individually. When the three pollutants were mixed in the air, the removal percentage decreased to 33.3%, 28.3%, and 28%. The degradation reaction of the three pollutants followed the pseudo first-order kinetics, which reflects that the photocatalytic reaction was controlled by the surface chemical reaction and the reaction rate was controlled by concentration of reactants.

scholarly journals Solar Photocatalytic Degradation of Typical Indoor Air Pollutants Using TiO2Thin Film Codoped with Iron(III) and Nitrogen

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Shuaijie Wang ◽  
Xingxing Cheng
Keyword(s):  
Indoor Air ◽  
Air Pollutants ◽  
Reaction Rate ◽  
Sol Gel ◽  
Visible Region ◽  
Reaction Rate Constant ◽  
Solar Light ◽  
Photocatalytic Ability ◽  
Vis Spectroscopy ◽  
Indoor Air Pollutants

A type of iron and nitrogen codoped titania thin film was prepared by sol-gel method to degrade three typical indoor air pollutants: formaldehyde (HCHO), ammonia (NH3), and benzene (C6H6) under solar light. X-ray diffraction (XRD), UV-Vis spectroscopy, and energy dispersive spectra (EDS) were employed to characterize the photocatalysts. The results showed that the Fe/N codoped TiO2had a stronger absorption in the visible region than pure, Fe-doped, and N-doped TiO2and exhibited excellent photocatalytic ability for the degradation of indoor HCHO, NH3, and C6H6. When the three pollutants existed in indoor air at the same time, the removal percentages of HCHO, NH3, or C6H6after 6 h photocatalytic reaction under solar light reached 48.8%, 50.6%, and 32.0%. The degradation reaction of the three pollutants followed the pseudo-first-order kinetics with the reaction rate constants in the order of 0.110 h−1for ammonia, 0.109 h−1for formaldehyde, and 0.060 h−1for benzene. The reaction rate constant decreased with the increase of initial reactant concentration, which reflected that there was oxidation competition between the substrate and its intermediate during the photocatalytic process.

scholarly journals Preparation, characterization and enhanced photocatalytic activity of Ni2+ doped titania under solar light

2010 ◽  
Vol 8 (1) ◽  
pp. 142-148 ◽  
Author(s):  
L. Gomathi Devi ◽  
Nagaraju Kottam ◽  
S. Girish Kumar ◽  
K. Eraiah Rajashekhar
Keyword(s):  
Band Gap ◽  
Anatase Phase ◽  
Sol Gel ◽  
Visible Region ◽  
Analytical Techniques ◽  
Red Shift ◽  
Solar Light ◽  
Spectral Studies ◽  
Doped Titania ◽  
Charge Carrier Trapping

AbstractAnatase TiO2 was prepared by sol-gel method through the hydrolysis of TiCl4. Ni2+ was doped into the TiO2 matrix in the concentration range of 0.02 to 0.1 at.% and characterized by various analytical techniques. Powder X-ray diffraction revealed only anatase phase for all the samples, while diffuse reflectance spectral studies indicated a red shift in the band gap absorption to the visible region. The photocatalytic activities of these photocatalysts were probed for the degradation of methyl orange under natural solar light. The photocatalyst with optimum doping of 0.08 at.% Ni2+, showed enhanced activity, which is attributed to: (i) effective separation of charge carriers and (ii) large red shift in the band gap to visible region. The influence of crystallite size and dopant concentration on the charge carrier trapping — recombination dynamics is investigated.

scholarly journals Growth of Zn1−x CdxO nanocrystalline thin films by sol-gel method and their characterization for optoelectronic applications

2014 ◽  
Vol 32 (4) ◽  
pp. 688-695 ◽  
Author(s):  
Munirah Munirah ◽  
Ziaul Khan ◽  
Mohd. Khan ◽  
Anver Aziz
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Visible Region ◽  
Zno Thin Films ◽  
Band Edge Emission ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cd Doping ◽  
Vis Spectroscopy ◽  
Doped Zno

AbstractThis paper describes the growth of Cd doped ZnO thin films on a glass substrate via sol-gel spin coating technique. The effect of Cd doping on ZnO thin films was investigated using X-ray diffraction (XRD), UV-Vis spectroscopy, photoluminescence spectroscopy, I–V characteristics and field emission scanning electron microscopy (FESEM). X-ray diffraction patterns showed that the films have preferred orientation along (002) plane with hexagonal wurtzite structure. The average crystallite sizes decreased from 24 nm to 9 nm, upon increasing of Cd doping. The films transmittance was found to be very high (92 to 95 %) in the visible region of solar spectrum. The optical band gap of ZnO and Cd doped ZnO thin films was calculated using the transmittance spectra and was found to be in the range of 3.30 to 2.77 eV. On increasing Cd concentration in ZnO binary system, the absorption edge of the films showed the red shifting. Photoluminescence spectra of the films showed the characteristic band edge emission centred over 377 to 448 nm. Electrical characterization revealed that the films had semiconducting and light sensitive behaviour.

scholarly journals Evolution of Monoclinic CaAl2O4 Nanocrystallites via Chemical Route and Its Optical Investigations

2021 ◽  
Vol 16 (2) ◽  
Author(s):  
Bindiya Goswami ◽  
Neelam Rani ◽  
Rachna Ahlawat
Keyword(s):  
Calcium Aluminate ◽  
Sol Gel ◽  
Visible Region ◽  
Photo Luminescence ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Phosphor Material ◽  
Vis Spectroscopy ◽  
Scherrer Formula ◽  
New Generation

Nanocrystalline calcium aluminate (CaAl2O4) powder is an adequate phosphor material. Calcium aluminate is a versatile member belongs to a category of alkaline earth aluminates phosphor. It has multifaceted applications in different areas such as photocatalysis, sensing, optoelectronic devices, displays, and imaging etc. In the present study, calcium aluminate has been prepared by well-known citrate sol-gel technique. X-ray diffraction (XRD) method has been used to analysis the amorphous and crystalline behavior of the prepared samples. The sample annealed at 800° indicates the monoclinic phase with enhanced intensity of the prominent diffraction peaks. By using Debye-Scherrer formula the grain size of crystalline powder is calculated ~10 nm. FTIR spectra confirmed the molecular orientation and bond structure in the prepared nanomaterial. Surface morphology and elemental composition present in prepared samples has been examined by Scanning electron microscope and energy dispersive spectroscopy. Uv-vis spectroscopy result showed red shift in the nanopowder with thermal treatment. In material science, due to their long-lasting photo-luminescence properties in visible region these aluminates are very attractive for evolution of new generation inorganic phosphor materials.

scholarly journals Effect of Synthesis Conditions of Nitrogen and Platinum Co-Doped Titania Films on the Photocatalytic Performance under Simulated Solar Light

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1074
Author(s):  
Daryna Ihnatiuk ◽  
Camilla Tossi ◽  
Ilkka Tittonen ◽  
Oksana Linnik
Keyword(s):  
Sol Gel ◽  
Visible Region ◽  
Solar Light ◽  
Photocatalytic Decomposition ◽  
Homogeneous Distribution ◽  
Synthesis Conditions ◽  
Simulated Solar Light ◽  
Titania Films ◽  
Doped Titania ◽  
Co Doped

Platinum and nitrogen co-doped titania films of different surface morphologies obtained via a sol-gel process have been tested for tetracycline hydrochloride photocatalytic decomposition under simulated solar light. Titania crystallization to anatase is shown by XRD for all films. A shift of the bandgap edge toward the visible region in absorption spectra and, consequently, a narrowing of the bandgap is observed for some films doped with nitrogen and/or exposed to UV pretreatment. The surface peculiarities of the samples are presented by an SEM and TEM investigation. The surface saturation by Pt and N with a homogeneous distribution of Pt ions on the surface as well as bulk as established by XPS and EDS data can be achieved with a certain synthesis procedure. The influence of the platinum content and of the pretreatment procedure on the state and atomic surface concentration of incorporated nitrogen and platinum is studied by XPS analysis: substitutional and interstitial nitrogen, non-metal containing fragments, Pt0, Pt2+ and Pt4+ ions. The photocatalytic activity of the films is ruled by the presence of Pt2+ ions and N rather than Pt0. The formation of the polycrystalline titania structure and Pt0 nanoparticles (NPs) is confirmed by TEM and electron diffraction images. The mechanism of primary photocatalytic processes is proposed.

scholarly journals Structural and optical characterization of aluminum zinc co-doped tin oxide grown by sol-gel spin coating techniques

2020 ◽  
Vol 18 (2) ◽  
pp. 109-117
Author(s):  
Oluwaseun Adedokun ◽  
Ismaila Bello ◽  
Olufunke Adedeji ◽  
Kamoru Talabi ◽  
Olaniyi Olatunji ◽  
...  
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Photon Energy ◽  
Tin Oxide ◽  
Spin Coating ◽  
Sol Gel ◽  
Visible Region ◽  
Gravimetric Method ◽  
X Ray Diffraction ◽  
Co Doped

Aluminum Zinc co-doped Tin Oxide (AZSO) thin film was grown by sol-gel spin coating techniques onto a glass substrate using various doping concentrations (0, 2, 4, 6, and 8 wt%) and the effect of doping on each sample were studied using structural analysis; X-ray Diffraction (XRD) pattern, gravimetric method; thin film thickness and UV photo-spectrometer; optical properties. The results of the XRD were revealed that all the peaks have a tetragonal phase of SnO2, which were oriented at the 110, 101, and 211 planes. The film thickness was observed to vary with doping concentration. In the visible region, all the film samples were exhibited at average transmittance. The coefficient of absorption was gradually increased with an increase in photon energy at a certain level with a decrease in the absorption coefficient as the photon energy increases further. At 550-800 nm range of wavelength, a high extinction coefficient (k) was recorded and the refractive index curves show regular dispersion behavior. The optical conductivity of the films followed a similar pattern, which showed that conductivity increased to a peak at 3.60 eV. The energy bandgap of the film samples (AZSO1 - AZSO5) is 4.095 eV, 4.103 eV, 4.087 eV, 4.114 eV, and 4.106 eV, respectively. The studies show that the properties of Al-Zn co-doped SnO2 films can be explored for optoelectronic applications.

Effect of W doping level on TiO2 on the photocatalytic degradation of Diuron

2016 ◽  
Vol 75 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Ghania Foura ◽  
Ahcène Soualah ◽  
Didier Robert
Keyword(s):  
Visible Light ◽  
Separation Efficiency ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Pure Tio2 ◽  
Solar Light ◽  
X Ray Diffraction ◽  
Simulated Solar Light ◽  
Uv Visible ◽  
Doped Titania

In the present study, three compositions of W-doped titania nano-photocatalyst are synthesized via the sol–gel method. The powders obtained were characterized by X-ray diffraction, Raman spectroscopy and UV–visible diffuse reflectance spectroscopy. The photocatalytic performances of the different photocatalysts are tested with respect to the degradation of Diuron in water solutions under simulated solar light and visible light irradiation. The W0.03Ti0.97O2 catalyst exhibits better photoactivity than the pure TiO2 even under simulated solar light and visible light. This improvement in activity was attributed to photoelectron/hole separation efficiency.

Degradation of Indoor Ammonia Using TiO2 Thin Film Doped with Iron(III) under Visible Light Illumination

2013 ◽  
Vol 668 ◽  
pp. 136-139
Author(s):  
Shuai Jie Wang ◽  
Hao Yu ◽  
Xue Qin Gao
Keyword(s):  
Thin Film ◽  
Visible Light ◽  
Tio2 Thin Film ◽  
Sol Gel ◽  
Visible Region ◽  
Reaction Rate Constant ◽  
Light Illumination ◽  
Doping Amount ◽  
Doped Tio2 ◽  
Vis Spectroscopy

A type of titania thin film doped with iron(III) was prepared by means of sol-gel method to degrade indoor ammonia (NH3) under visible light irradiation. The photocatalysts was characterized by X-ray diffraction (XRD) and UV-vis spectroscopy. The results demonstrated that the adsorption edge of doped TiO2 thin film had red shifts and the doped TiO2 thin film had a stronger absorption than undoped TiO2 thin film in the visible region. Doping amount of Fe(III) effected the photocatalytic actitivity of Fe-doped TiO2 thin film significantly. The optimal doping amount of Fe(III) was 1%(mole fraction). Using the optimal Fe-doped TiO2 thin film, the removal percentage of NH3 after 9h phtocatalytic reaction under visible light reached 53.1%. The degradation reaction of NH3 was successfully described by the pseudo first-order kinetics. The reaction rate constant decreased with the increase of initial concentration of NH3, which reflected that there was oxidation competition between NH3 and its intermediate during the photocatalytic process.

Photocatalytic Degradation of Methylene Blue by NiO Thin Films under Solar Light Irradiation

2019 ◽  
Vol 56 ◽  
pp. 152-157 ◽  
Author(s):  
Abdelouahab Noua ◽  
Hichem Farh ◽  
Rebai Guemini ◽  
Oussama Zaoui ◽  
Tarek Diab Ounis ◽  
...  
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Visible Region ◽  
Optical Transmittance ◽  
Dip Coating ◽  
Light Irradiation ◽  
Solar Light ◽  
Solar Light Irradiation

Nickel oxide (NiO) thin films were successfully deposited by sol-gel dip-coating method on glass substrates. The structural, morphological and optical properties in addition to the photocatalytic activity of the prepared films were investigated. The results show that the films have a polycrystalline NiO cubic structure with dense NiO grains and average optical transmittance in the visible region. The photocatalytic properties of the films were studied through the degradation of methylene blue and 89% of degradation was achieved for 4.5h of solar light irradiation exposure which indicates the capability of NiO photocatalytic activity.

Structural and Optical Properties of Al Co-Doped ZnCoO Thin Film

2014 ◽  
Vol 989-994 ◽  
pp. 656-659
Author(s):  
Ping Cao ◽  
Yue Bai
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Al Doping ◽  
X Ray ◽  
Uv Emission ◽  
Uv Absorption Spectroscopy ◽  
Co Doped

Al co-doped ZnCoO thin film has been prepared by a sol-gel method. The structural and optical properties of the sample were investigated. X-ray diffraction and UV absorption spectroscopy analyses indicate that Al3+ and Co2+ substitute for Zn2+ without changing the wurtzite structure. With the Al doping, the visible emission increased and the UV emission decreased, which is attributed to the increase of O vacancies and Zn interstitials.

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