scholarly journals Effect of dopant concentration on photocatalytic activity of TiO2 film doped by Mn non-uniformly

2006 ◽  
Vol 4 (2) ◽  
pp. 234-245 ◽  
Author(s):  
Kaijian Zhang ◽  
Wei Xu ◽  
Xinjun Li ◽  
Shaojian Zheng ◽  
Gang Xu
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Degradation Rate ◽  
Dopant Concentration ◽  
Pure Titanium ◽  
Open Circuit ◽  
Tio2 Films ◽  
Uniform Doping ◽  
Effect Of Doping

AbstractThe thin films of TiO2 doped by Mn non-uniformly were prepared by sol-gel method under process control. In our preceding study, we investigated in detail, the effect of doping mode on the photocatalytic activity of TiO2 films showing that Mn non-uniform doping can greatly enhance the activity. In this study we looked at the effect of doping concentration on the photocatalytic activity of the TiO2 films. In this paper, the thin films were characterized by UV-vis spectrophotometer and electrochemical workstation. The activity of the photocatalyst was also evaluated by photocatalytic degradation rate of aqueous methyl orange under UV radiation. The results illustrate that the TiO2 thin film doped by Mn non-uniformly at the optimal dopant concentration (0.7 at %) is of the highest activity, and on the contrary, the activity of those doped uniformly is decreased. As a comparison, in 80 min, the degradation rate of methyl orange is 62 %, 12 % and 34 % for Mn non-uniform doping film (0.7 at %), the uniform doping film (0.7 at %) and pure titanium dioxide film, respectively. We have seen that, for the doping and the pure TiO2 films, the stronger signals of open circuit potential and transient photocurrent, the better photocatalytic activity. We also discusse the effect of dopant concentration on the photocatalytic activity of the TiO2 films in terms of effective separation of the photon-generated carriers in the semiconductor.

scholarly journals The Role of H2C2O4 and Na2CO3 as Precipitating Agents on The Physichochemical Properties and Photocatalytic Activity of Bismuth Oxide

2020 ◽  
Vol 18 (1) ◽  
pp. 129-137
Author(s):  
Yayuk Astuti ◽  
Rizka Andianingrum ◽  
Abdul Haris ◽  
Adi Darmawan ◽  
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Physicochemical Properties ◽  
Bismuth Oxide ◽  
Rate Constants ◽  
Degradation Rate ◽  
Precipitation Method ◽  
Methyl Orange Degradation ◽  
Methyl Orange Dye

AbstractSynthesis of bismuth oxide synthesis through the precipitation method using H2C2O4 and Na2CO3 precipitating agents, identification of physicochemical properties and its photocatalysis activity for methyl orange degradation were conducted. The bismuth oxide synthesis was undertaken by dissolving Bi(NO3)3.5H2O in HNO3, then added precipitating agents to form precipitate. The results showed that bismuth oxide produced by H2C2O4 precipitating agent was a yellow powder containing a mixture of α-Bi2O3 (monoclinic) and β-Bi2O3 (tetragonal), porous with size of 28-85 μm. Meanwhile, the use of Na2CO3 as precipitating agent resulted in bismuth oxide consisting of α-Bi2O3 and β-Bi2O3 and Bi2O4, irregular shape without pore being 40-115 μm in size. Bismuth oxide synthesized with H2C2O4 precipitating agent showed higher photocatalytic activity compared to bismuth oxide synthesized using Na2CO3 on degrading methyl orange dye with degradation rate constants of 2.35x10-5 s-1 for H2C2O4 and 1.81x10-5 s-1 for Na2CO3.

The Study on the Influential Factors of Photocatalytic Performance of Eosin-Sensitized TiO2 Nanoparticles

2013 ◽  
Vol 827 ◽  
pp. 3-7
Author(s):  
Shun Jiang He ◽  
Xue Yan Du ◽  
Qiao Wang ◽  
Jing Xu
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photocatalytic Degradation ◽  
Degradation Rate ◽  
Photocatalytic Performance ◽  
Influential Factors ◽  
Sunlight Irradiation ◽  
Sensitization Time

The photocatalytic activity of eosin-sensitized TiO2 nanoparticles on photocatalytic degradation rate (PDR) of methyl orange under sunlight irradiation was studied. The influential factors on the degradation, such as eosin concentration, TiO2 dosage, sensitization time and sensitization temperature were also investigated. The results show that: The performance of TiO2 nanoparticles for PDR of methyl orange has been improved obviously for eosin sensitizing. The PDR of methyl orange reached 45.28% under the conditions of eosin concentration of 20mg/L, TiO2 dosage of 0.5000g/L, sensitization time of 24h and sensitization temperature of 20°C.

Synthesis and Characterization of Refluxed Sols and TiO2 Thin Films Using TiOSO4

2007 ◽  
Vol 336-338 ◽  
pp. 2189-2192
Author(s):  
Lei Ge ◽  
Ming Xia Xu ◽  
Hai Bo Fang ◽  
Ming Sun
Keyword(s):  
Thin Films ◽  
Methyl Orange ◽  
Uv Light ◽  
Methyl Orange Solution ◽  
Light Transmittance ◽  
Tio2 Films ◽  
Tio2 Thin Films ◽  
Photocatalytic Activities ◽  
Orange Solution ◽  
Degradation Of Methyl Orange

Nano anatase TiO2 thin films on glass slide substrates were prepared via a dip-coating method using refluxed sols (RS) as precursors, then dried under infrared light and calcined at 500°C for 30min. The RS sols and TiO2 films were characterized by FT-IR, XRD, TEM, UV-Vis and SEM. The photocatalytic activities of the film samples were tested by the degradation of methyl orange solution with a concentration of 10mg/L under UV light irradiation. The results reveal that the RS sols are flavescent, alkalescent and contain needle-like anatase crystals. The TiO2 films are uniform, compact and transparent, their maximal light transmittance exceed 80% under visible light region. The degradation of methyl orange results illustrate that the RS-6 TiO2 thin films show the best photocatalytic activities, the decoloration rate of the methyl orange solution with RS-6 TiO2 thin films reachs 99% after irradiated 160min under UV light.

Synthesis and Recycle of ZnO Particles for Degradation of Methyl Orange Aqueous Solution

2011 ◽  
Vol 121-126 ◽  
pp. 587-591 ◽  
Author(s):  
Li Qin Wang ◽  
Xiang Ni Yang ◽  
Xiu Li Zhao ◽  
Yang Han ◽  
Rui Jun Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Lamellar Structure ◽  
Degradation Rate ◽  
Mesoporous Structure ◽  
High Photocatalytic Activity ◽  
Type Iv ◽  
Zno Particles ◽  
Adsorption Desorption

The ZnO particles with mesoporous and lamellar structure were synthesized in the method of precipitation, using zinc acetate as precursor. The ZnO particles were characterized by the means of scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and N2 adsorption–desorption measurements. The photoactivity of as-prepared ZnO particles was evaluated by degradation experiment of methyl orange aqueous solution. The results showed the obtained ZnO particles were irregular polygons with lamellar structure, and the particle size was in the range of 50 nm to 300 nm. According to XRD and N2 absorption results, ZnO particles were pure and integrated crystals with high crystallinity, and adsorption-desorption isotherms correspond to the typical type IV isotherm with a hysteresis loop of type H3, which showed ZnO particles had mesoporous structure with slit pore shape. The ZnO particles had high photocatalytic activity, the maximum degradation rate of methyl orange aqueous solution can reach 99%. When reused for the fifth time, the photocatalytic activity of ZnO particles was similar with the fresh ones, and recycled for the tenth time, the degradation rate of methyl orange aqueous solution still standed by 84.7%.

scholarly journals A Review on the Pathways of the Improved Structural Characteristics and Photocatalytic Performance of Titanium Dioxide (TiO2) Thin Films Fabricated by the Magnetron-Sputtering Technique

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 598 ◽  
Author(s):  
Yu-Hsiang Wang ◽  
Kazi Hasibur Rahman ◽  
Chih-Chao Wu ◽  
Kuan-Chung Chen
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Magnetron Sputtering ◽  
Band Gap ◽  
Vapor Deposition ◽  
Degree Of Crystallinity ◽  
Tio2 Films ◽  
Tio2 Thin Films

Titanium dioxide (TiO2) thin films are used for a broad range of applications such as wastewater treatment, photocatalytic degradation activity, water splitting, antibacterial and also in biomedical applications. There is a wide range of synthesis techniques for the deposition of TiO2 thin films, such as chemical vapor deposition (CVD) and physical vapor deposition (PVD), both of which are well known deposition methods. Layer by layer deposition with good homogeneity, even thickness and good adhesive nature is possible by using the PVD technique, with the products being used for photocatalytic applications. This review studies the effects of magnetron sputtering conditions on TiO2 films. This innovative technique can enhance the photocatalytic activity by increasing the thickness of the film higher than any other methods. The main purpose of this article is to review the effects of DC and RF magnetron sputtering conditions on the preparation of TiO2 thin films for photocatalysis. The characteristics of TiO2 films (i.e., structure, composition, and crystallinity) are affected significantly by the substrate type, the sputtering power, the distance between substrate and target, working pressure, argon/oxygen ratio, deposition time, substrate temperature, dopant types, and finally the annealing treatment. The photocatalytic activity and optical properties, including the degree of crystallinity, band gap (Eg), refractive index (n), transmittance (T), and extinction coefficient (k), of TiO2 films are dependent on the above- mentioned film characteristics. Optimal TiO2 films should have a small particle size, a strong degree of crystallinity, a low band gap, a low contact angle, a high refractive index, transmittance, and extinction coefficient. Finally, metallic and nonmetallic dopants can be added to enhance the photocatalytic activity of TiO2 films by narrowing the band gap.

Photocatalytic Degradation of Methyl Orange: Influence of H2O2 in the TiO2-Based System

2008 ◽  
Vol 8 (2) ◽  
pp. 728-732 ◽  
Author(s):  
Luminita Andronic ◽  
Simona Manolache ◽  
Anca Duta
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photocatalytic Oxidation ◽  
Internal Surface ◽  
Doctor Blade ◽  
Spray Pyrolysis Deposition ◽  
Methyl Orange Concentration ◽  
Degradation Of Methyl Orange

The purpose of this study was to investigate the photocatalytic oxidation of a reactive azo dye. The photocatalytic activity of the TiO2 was studied using a reactor equipped with UV-A sources, with maximum emission at 365 nm. The photocatalytic activity of the TiO2 powder (99.9% anatase) and thin films has been measured through the decomposition of methyl orange solutions. The thin film was prepared by doctor blade and spray pyrolysis deposition (SPD). The TiO2 suspensions were prepared at 1 g/L concentration, and the initial methyl orange concentration was fixed at 7.8125 mg/L. The influence of the TiO2 (powder or thin films) and/or O2 and H2O2 on the photobleaching rate, was tested under different experiments, at pH = 5. Thin films (doctor blade) of TiO2 formed of mezo-sized aggregates formed of nanosized anatase crystallites show better photobleaching efficiency than thin film(SPD) due to their large internal surface. The rate is even higher in H2O2 compared to oxygen environment.

Preparation of TiO2 Films on Quartz Glass Plate and Its Study of Photocatalytic Properties in Ultrasound

2011 ◽  
Vol 284-286 ◽  
pp. 970-973 ◽  
Author(s):  
Ping Zhang ◽  
Hai Feng Yang ◽  
Shi Wei Lin ◽  
Yang Cao ◽  
Feng Wen
Keyword(s):  
Thin Films ◽  
Methyl Orange ◽  
Quartz Glass ◽  
Degradation Rate ◽  
Sol Gel ◽  
Glass Plate ◽  
Dip Coating ◽  
Photocatalytic Properties ◽  
Ultrasonic Power ◽  
The Impact

TiO2thin films were prepared successfully by dip-coating technique and sol-gel method on quartz glass plate. The photocatalytic properties of the fabricated TiO2thin films to decompose the Methyl orange(MO) solution with or wihtout ultrasonic vibrations were investigated. Experimental results showed that TiO2thin films had best photocatalytic properties when it was coated four layers and calcined at 500°C. The sonophotocatalytic technology is more effective for the decomposition of methyl orange than single TiO2photocatalytic,the degradation rate increased by 35%.In addition,the degradation rate is affected by reaction time, the impact of ultrasonic power.

Photocatalytic Methyl Orange Degradation on TiO2-NaX Composite

2010 ◽  
Vol 129-131 ◽  
pp. 804-807
Author(s):  
Hong Wang ◽  
Yang Yu ◽  
Wen Jie Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Solid State ◽  
Degradation Rate ◽  
Pure Tio2 ◽  
Methyl Orange Degradation ◽  
Maximum Value ◽  
Photocatalytic Activities ◽  
Addition Amount ◽  
Better Than

Photocatalytic activities of simple mixture of TiO2 and NaX, and TiO2-NaX composite prepared by solid-state dispersion method were investigated. Methyl orange degradation rate increased sharply when TiO2 concentration was low and reached its maximum value at TiO2 concentration of 200 mg/l when using pure TiO2. After 120 min of irradiation, methyl orange degradation rate could reach 98.4%, which means nearly all of the dye degraded after two hours. The photocatalytic activity of TiO2 and NaX simple mixture increased with increasing amount of NaX up to 60.4% when NaX amount was 1.4 g/l. The composite TiO2-NaX prepared by grinding had lower activity at various NaX addition amount. The photocatalytic activity of composite TiO2-NaX prepared by solid-state dispersion was better than the composite before calcination. However, the maximum degradation rate was only 41.2%, which was still lower than pure TiO2.

Sol-Gel Preparation, Characterization and Photocatalytic Activity of Co Doped Nano-TiO2

2010 ◽  
Vol 177 ◽  
pp. 54-57 ◽  
Author(s):  
Li Na Meng ◽  
Wen Yuan Xu ◽  
Ting Xu
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Sol Gel ◽  
Inhibitory Effect ◽  
Pure Tio2 ◽  
Tio2 Thin Films ◽  
Doped Tio2 ◽  
Co Doping ◽  
Co Doped

Co doped TiO2 nanoparticles and thin films were prepared from Ti(OC4H9)4 by sol-gel method. The influence of Co-doping and its content on the crystallite structure and phase composition of TiO2 was systematically investigated by SEM and XRD, the precursor was analysed by TGA. The photocatalytic activity of nanocomposites was investigated in the photocatalytic degradation of methyl orange. The results indicated that the inhibitory effect of Co-doping on the phase transformation of TiO2 from anatase to rutile receded obviously when the calcination temperature was changed to 650°C from 550°C. Under the ultraviolet light radiation, the favourite Co-doping concentration was 1% and the obtained Co doped TiO2 thin films exhibited higher photocatalytic activity than nanoparticles and pure TiO2 in the photodegradation of methyl orange.

scholarly journals Effect of the Titanium Isopropoxide:Acetylacetone Molar Ratio on the Photocatalytic Activity of TiO2 Thin Films

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4326 ◽  
Author(s):  
Jekaterina Spiridonova ◽  
Atanas Katerski ◽  
Mati Danilson ◽  
Marina Krichevskaya ◽  
Malle Krunks ◽  
...  
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Irradiation Time ◽  
Fold Increase ◽  
Molar Ratio ◽  
Spray Pyrolysis Method ◽  
Chemical Spray Pyrolysis ◽  
Tio2 Films ◽  
Tio2 Thin Films ◽  
Spray Solution

TiO2 thin films with different titanium isopropoxide (TTIP):acetylacetone (AcacH) molar ratios in solution were prepared by the chemical spray pyrolysis method. The TTIP:AcacH molar ratio in spray solution varied from 1:3 to 1:20. TiO2 films were deposited onto the glass substrates at 350 °C and heat-treated at 500 °C. The morphology, structure, surface chemical composition, and photocatalytic activity of the obtained TiO2 films were investigated. TiO2 films showed a transparency of ca 80% in the visible spectral region and a band gap of ca 3.4 eV irrespective of the TTIP:AcacH molar ratio in the spray solution. TiO2 films consist of the anatase crystalline phase with a mean crystallite size in the range of 30–40 nm. Self-cleaning properties of the films were estimated using the stearic acid (SA) test. A thin layer of 8.8-mM SA solution was spin-coated onto the TiO2 film. The degradation rate of SA as a function of irradiation time was monitored by Fourier-transform infrared spectroscopy (FTIR). An increase in the TTIP:AcacH molar ratio from 1:4 to 1:8 resulted in a ten-fold increase in the photodegradation reaction rate constant (from 0.02 to the 0.2 min−1) under ultraviolet light and in a four-fold increase under visible light.

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