The Solvent Influent on the Properties of TiO2: V4+ Nanoparticles Prepared by Hydrothermal Method

2012 ◽  
Vol 548 ◽  
pp. 105-109
Author(s):  
Nguyen Minh Thuy ◽  
Duong Quoc Van ◽  
Le Thi Hong Hai ◽  
Nguyen Manh Nghia ◽  
Nguyen Hong Quan
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Hydrothermal Method ◽  
Crystal Size ◽  
Anatase Phase ◽  
Visible Light Region ◽  
Average Crystal Size ◽  
Light Region ◽  
Visible Irradiation ◽  
Normalized Concentration

TiO2and Vanadium doped TiO2nanoparticles were synthesized by hydrothermal method. The solvents are water, oleic acid, or oxalic acid, which have affected the forms and sizes of the grains in the samples. The solvent can make the spherical nanograins, or the stick form grains, what influences the photo activity of the materials. The Vanadium doped TiO2nanoparticles had identical anatase phase with average crystal size of 8-20nm. The absorption spectra of doped samples exhibited the long tailed absorption in the visible light region above 380nm. The photocatalytic activity under the irradiation of visible light was evaluated by the degradation of phenol aqueous solutions, which is one of the products from photocatalytic oxidations of benzene. The samples TiO2:0.5%V4+have visible light photocatalystic activity; after 360min under the visible irradiation the normalized concentration of phenol decreased to 9%.

Characterization and activity of visible-light driven TiO2 photocatalyst doped with tungsten

2010 ◽  
Vol 62 (9) ◽  
pp. 2128-2133 ◽  
Author(s):  
T. Putta ◽  
M. C. Lu ◽  
J. Anotai
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Anatase Phase ◽  
Sol Gel ◽  
Light Illumination ◽  
Visible Light Region ◽  
Light Region ◽  
Acid Type ◽  
Visible Light Driven ◽  
Amorphous Tio2

This research aimed to expand the activity of TiO2 down to the visible light region by modifying the sol-gel conditions and doping with tungsten. The optimum conditions for calcination temperature, acid type, and heating rate were 200°C, HNO3, and 1°C/min, respectively. The undoped TiO2 synthesized under these conditions could significantly absorb the visible light whereas the commercial Degussa P-25 could not. The absorptivity decreased sequentially as the wavelength increased from 400 to 700 nm. Within 6 h of 2-W blue-light illumination, 23% of 0.1 mM 2-chlorophenol was removed. The XRD result showed that the crystalline was anatase phase. The visible-light absorption property of the TiO2 became even better when doped with tungsten. At the optimum W to TiO2 ratio of 0.5%, the degradation of 0.1 mM 2-chlorophenol increased to 53% indicating a higher photocatalytic activity. Both crystalline and amorphous TiO2 could exhibit the photocatalytic activity under the visible light region.

PHOTOCATALYTIC ACTIVITY UNDER VISIBLE LIGHT REGION OF Ca-MODIFIED TiO2NP FILMS PREPARED BY SPARKING OFF Ca-ELECTROPLATED Ti TIPS

2018 ◽  
Vol 25 (Supp01) ◽  
pp. 1840002 ◽  
Author(s):  
NIDCHAMON JUMRUS ◽  
ARISARA PANTHAWAN ◽  
TEWASIN KUMPIKA ◽  
WATTIKON SROILA ◽  
EKKAPONG KANTARAK ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Quartz Substrate ◽  
Ambient Air ◽  
Visible Light Region ◽  
Structural And Optical Properties ◽  
Uniform Size ◽  
Light Region ◽  
Vis Spectroscopy ◽  
Electroplating Process

In this work, calcium (Ca)-modified titanium dioxide (TiO2) nanoparticulate (NP) films were successfully prepared using sparking off Ca-electroplated Ti tips. Aqueous solution of calcium carbonate (CaCO3) was used as electrolyte in the electroplating process. The experiment was carried out using electric current of 0.02[Formula: see text]mA applied to titanium electrodes for 10[Formula: see text]min. The NP films with small and uniform size were deposited on quartz substrate using the sparking process with a high DC voltage of 4[Formula: see text]kV in ambient air. The as-deposited NP films were then annealed at 800∘C, 900∘C and 1000∘C for 3[Formula: see text]h under atmospheric pressure to improve their crystallinity. Morphology, structural and optical properties of the NP films were characterized by SEM, XRD, Raman, XPS and UV-Vis spectroscopy. The effects of annealing temperature on the properties of the as-deposited and annealed NP films were reported. Furthermore, photocatalytic activity against 10 [Formula: see text]M of methylene blue (MB) under visible light region will be discussed.

Preparation of Fe/N Co-Doped TiO2 Powders by Mild Hydrothermal Method

2014 ◽  
Vol 804 ◽  
pp. 217-220 ◽  
Author(s):  
Jun Na Xu ◽  
Wen Xiu Liu ◽  
Peng Sun ◽  
Ming Guan ◽  
Wen Bin Cao
Keyword(s):  
Grain Size ◽  
Visible Light ◽  
Hydrothermal Method ◽  
Visible Light Irradiation ◽  
Light Absorption ◽  
Visible Light Region ◽  
Light Region ◽  
One Step ◽  
Lower Temperature ◽  
Co Doped

Yellow colored anatase Fe/N co-doped TiO2powders have been successfully synthesized by one step hydrothermal method at a lower temperature. The grain size was about 10 nm and the specific surface area of the powders ranged from 160 to 166 m2/g. The light absorption of Fe/N co-doped TiO2powders was enhanced in the visible light region of 400~500 nm and a new absorption peak at about 470 nm appeared when the Fe/Ti ratio exceeded 0.5%. The visible light photoactivity of Fe/N co-doped TiO2powders has been greatly improved than that of un-doped TiO2powders under visible light irradiation.

scholarly journals N-Doped Carbon-Coated ZnS with Sulfur-Vacancy Defect for Enhanced Photocatalytic Activity in the Visible Light Region

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1657 ◽  
Author(s):  
Hao Peng ◽  
Daixin Liu ◽  
Xiaogang Zheng ◽  
Xiaojin Fu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Vacancy Defect ◽  
Visible Light Region ◽  
Sulfur Vacancy ◽  
Cycle Times ◽  
Light Region ◽  
Efficient Charge ◽  
Visible Light Driven ◽  
Carbon Coated

In this work, N-doped carbon-coated ZnS with a sulfur-vacancy defect (ZnS@N-C) was performed for the visible-light-driven photodegradation of tetracycline hydrochloride (TCH). The obtained ZnS@N-C exhibited enhanced photocatalytic activity compared with ZnS for TCH removal. Among these ZnS@N-C composites, ZnS@N-C-3 with N-doped content of 3.01% (100 nm) presented the best visible-light photocatalytic activity and superior long-term photocatalytic stability after five cycle times for TCH removal in the visible light region. This may be ascribed to the interface between the N-doped carbon shell and ZnS with a sulfur-vacancy defect for efficient charge transfer and the restrained recombination of charge carriers. Electron spin resonance (ESR) results indicate that the ·O2‒ radical plays a crucial role in the enhanced photocatalytic activity of ZnS@N-C-3.

Overall water splitting using (oxy)nitride photocatalysts

2006 ◽  
Vol 78 (12) ◽  
pp. 2267-2276 ◽  
Author(s):  
Kazuhiko Maeda ◽  
Kentaro Teramura ◽  
Nobuo Saito ◽  
Yasunobu Inoue ◽  
Hisayoshi Kobayashi ◽  
...  
Keyword(s):  
Solid Solution ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Water Splitting ◽  
Electronic Configuration ◽  
Oxide Nanoparticles ◽  
Visible Light Region ◽  
Overall Water Splitting ◽  
Light Region

Oxynitride photocatalysts with d10 electronic configuration are presented as effective non-oxide catalysts for overall water splitting. Germanium nitride (β-Ge3N4) having a band gap of 3.8-3.9 eV modified with RuO2 nanoparticles as a cocatalyst is shown to achieve stoichiometric decomposition of H2O into H2 and O2 under UV irradiation (λ > 200 nm). A novel solid solution of GaN and ZnO, (Ga1-xZnx)(N1-xOx), with a band gap of 2.4-2.8 eV (depending on composition) achieves overall water splitting under visible light (λ > 400 nm) when loaded with an appropriate cocatalyst. The narrower band gap of the solid solution is attributed to the bonding between Zn and N atoms at the top of the valence band. The photocatalytic activity of (Ga1-xZnx)(N1-xOx) for overall water splitting is strongly dependent on both the cocatalyst and the crystallinity and composition of the material. The quantum efficiency of (Ga1-xZnx)(N1-xOx) with Rh and Cr mixed-oxide nanoparticles is 2-3 % at 420-440 nm, which is the highest reported efficiency for overall water splitting in the visible-light region.

scholarly journals Enhancing the photocatalytic activity of Cu0.25Zn0.75S nanodisks by metallic Ag loading in the visible-light region

RSC Advances ◽  
2019 ◽  
Vol 9 (24) ◽  
pp. 13787-13796 ◽  
Author(s):  
Jinyang Zhang ◽  
Fuyan Kang ◽  
Hao Peng ◽  
Jing Wen ◽  
Xiaogang Zheng
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Organic Pollutants ◽  
Visible Light Irradiation ◽  
Rhodamine B ◽  
Methyl Violet ◽  
Light Irradiation ◽  
Visible Light Region ◽  
Ciprofloxacin Hydrochloride ◽  
Light Region

Ag-loaded Cu0.25Zn0.75S (Ag/Cu0.25Zn0.75S) photocatalysts were synthesized for the photodegradation of organic pollutants such as rhodamine B (RhB), methyl violet (MV) and ciprofloxacin hydrochloride (CIP) under visible-light irradiation.

scholarly journals A Comparison Study of Photocatalytic Activity of Fe3O4/TiO2 and Ag/TiO2 on the Degradation of 2, 4-Dichlorophenol

2020 ◽  
Author(s):  
narjes esmaeili ◽  
azadeh ebrahimian pirbazari ◽  
Ziba Khodaee
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Crystal Size ◽  
Anatase Phase ◽  
Organic Pollutant ◽  
Analytical Techniques ◽  
Pure Tio2 ◽  
Tio2 Anatase ◽  
Structure Morphology ◽  
Xrd Patterns

In this work, pure TiO2 and binary nanocomposites of Fe3O4/TiO2 and Ag/TiO2 were synthesized in order to improve photocatalytic performance of these samples for degradation of 2, 4-dichlorophenol (2, 4-DCP) as an organic pollutant. A range of analytical techniques including XRD, DRS, SEM/EDX, and elemental mapping were employed to reveal the crystal structure, morphology and property of the nanocomposites. XRD data demonstrated that the prepared samples are purely in TiO2 anatase phase and cubic spinel Fe3O4 exist in the synthesized nanocomposite. We calculated the TiO2 crystal size from XRD patterns, in the range of 8.35-11.09 nm. The presence of Ag, Fe, O, and Ti atoms in the synthesized nanocomposites was confirmed by SEM/EDX. We obtained 30.43, 32.02 and 42.40 % degradation of 2, 4-DCP (100 ml 2, 4-DCP 40 ppm and 0.01 g catalyst) for pure TiO2, Fe3O4/TiO2 and Ag/TiO2, respectively, after 180 min of irradiation under visible light. Similar conditions were employed for 2, 4-DCP degradation under UV irradiation, we obtained 53.05, 51.00 and 71.50 % degradation of 2, 4-DCP pure TiO2, Fe3O4/TiO2 and Ag/TiO2, respectively. Thus, the synthesized binary nanocomposites exhibited higher photocatalytic activity compared to pure TiO2 under visible light.

scholarly journals A Comparison Study of Photocatalytic Activity of Fe3O4/TiO2 and Ag/TiO2 on the Degradation of 2, 4-Dichlorophenol

2020 ◽  
Author(s):  
Narjes Esmaeili ◽  
Azadeh Ebrahimian Pirbazari ◽  
Ziba Khodaee
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Crystal Size ◽  
Anatase Phase ◽  
Organic Pollutant ◽  
Analytical Techniques ◽  
Pure Tio2 ◽  
Tio2 Anatase ◽  
Structure Morphology ◽  
Xrd Patterns

In this work, pure TiO2 and binary nanocomposites of Fe3O4/TiO2 and Ag/TiO2 were synthesized in order to improve photocatalytic performance of these samples for degradation of 2, 4-dichlorophenol (2, 4-DCP) as an organic pollutant. A range of analytical techniques including XRD, DRS, SEM/EDX, and elemental mapping were employed to reveal the crystal structure, morphology and property of the nanocomposites. XRD data demonstrated that the prepared samples are purely in TiO2 anatase phase and cubic spinel Fe3O4 exist in the synthesized nanocomposite. We calculated the TiO2 crystal size from XRD patterns, in the range of 8.35-11.09 nm. The presence of Ag, Fe, O, and Ti atoms in the synthesized nanocomposites was confirmed by SEM/EDX. We obtained 30.43, 32.02 and 42.40 % degradation of 2, 4-DCP (100 ml 2, 4-DCP 40 ppm and 0.01 g catalyst) for pure TiO2, Fe3O4/TiO2 and Ag/TiO2, respectively, after 180 min of irradiation under visible light. Similar conditions were employed for 2, 4-DCP degradation under UV irradiation, we obtained 53.05, 51.00 and 71.50 % degradation of 2, 4-DCP pure TiO2, Fe3O4/TiO2 and Ag/TiO2, respectively. Thus, the synthesized binary nanocomposites exhibited higher photocatalytic activity compared to pure TiO2 under visible light.

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