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.

scholarly journals Structural and optical properties of AgCl-sensitized TiO2 (TiO2 @AgCl) prepared by a reflux technique under alkaline condition

Cerâmica ◽  
2018 ◽  
Vol 64 (370) ◽  
pp. 190-196 ◽  
Author(s):  
V. A. Mu’izayanti ◽  
H. Sutrisno
Keyword(s):  
Visible Light ◽  
Surface Area ◽  
Alkaline Condition ◽  
Visible Light Region ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Light Region ◽  
Vis Spectroscopy ◽  
Xrd Patterns ◽  
Tio2 Rutile

Abstract The AgCl-sensitized TiO2 (TiO2@AgCl) has been prepared from the precursor of TiO2-rutile type which on its surface adsorb chloride anion (Cl-) and various amounts of silver using AgNO3 as starting material: AgNO3/(AgNO3+TiO2) mass ratio of 0.00, 1.14, 3.25, 6.38 and 10.32%. Reflux under alkaline condition was the employed technique. All samples were characterized by X-ray diffraction (XRD) and diffuse reflectance UV-vis spectroscopy. The sample without the addition of AgNO3 was analyzed by scanning electron microscope and surface area analyzer. The morphology of the sample showed a distribution of microspheres of approximately 0.5 to 1.0 µm and the specific surface area was 68 m2/g. XRD patterns indicated that the sample without the addition of AgNO3 contained two types of TiO2: rutile (major) and anatase (minor), whereas the samples with the addition of AgNO3 consisted of one phase of AgCl and two types of TiO2: rutile and anatase. The bandgaps of the samples were in the range of 2.97 to 3.24 eV, which were very close to the bandgap of intrinsic TiO2 powder. The presence of 0.8, 2.6 and 4.4 wt% of AgCl in each sample resulted in an additional bandgap in visible light region of 1.90, 1.94 and 2.26 eV, respectively, whereas the presence of 9.4 wt% of AgCl in the sample resulted in two bandgaps in visible light region of 1.98 and 1.88 eV.

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.

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.

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%.

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.

Effect of Calcination Temperature on Light Absorption and Visible Light Photocatalytic Activity of N Doped TiO2 Nano-Crystalline

2020 ◽  
Vol 12 (3) ◽  
pp. 449-453 ◽  
Author(s):  
Bo Wang ◽  
Ruiling Zhang ◽  
Jin Xu ◽  
Songyan Qin ◽  
Jiajun Zheng ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Hydroxyl Groups ◽  
Visible Light Region ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Nano Crystalline ◽  
Light Region ◽  
Visible Light Photocatalytic

N doped TiO2 nano-crystalline was prepared through hydrolysis-precipitation process in the presence of ammonia water. The resulting materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). It was found that N was incorporated into the lattice of TiO2 through substituting lattice oxygen atoms and coexisted in the forms of substitutional N (O–Ti–N) and interstitial N (Ti–O–N). Further, doping with N could greatly improve the phase transformation of TiO2 from rutile to anatase and light absorption in visible light region. The high visible light photocatalytic activity for the degradation of RhB of N doped TiO2 was mainly attributed to the small crystallite size, mixed phase composition, intense light absorption in visible light region, narrow band gap energy and surface hydroxyl groups.

Influence of Pt and Pd Modification on the Visible Light Photocatalytic Activity of N-Doped Titania Photocatalysts

2016 ◽  
Vol 16 (4) ◽  
pp. 3570-3576 ◽  
Author(s):  
Yulong Hu ◽  
Fu Dong ◽  
Hongfang Liu ◽  
Xingpeng Guo
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Metallic State ◽  
Visible Light Region ◽  
Electron Hole ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Light Region ◽  
Doped Titania ◽  
Visible Light Photocatalytic

Pd and Pt modified N-doped titania nanoparticle powders were prepared by a facile sol–gel method. Nitrogen doping and metal modification were carried out simultaneously during the preparation process. The as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and X-ray photoelectron spectroscopy (XPS). The visible light photocatalytic activities of the asprepared samples were evaluated by analyzing their effect on the photocatalytic decomposition of methyl orange (MO). The chemical state of the metal is the key factor determining the performance of metal modified N-doped titania. The Pd used to modify the N-doped titania (Pd-NT) in our study was of the PdOx(x≤2) species, which increased the absorbance in the visible light region, decreased the recombination of photo-generated electron–hole pairs, and resulted in a significant enhancement in the visible light photocatalytic activity. The Pt species used to modify the N-doped titania (Pt-NT) was mainly in the metallic state, which resulted in a decrease in the absorbance in the visible light region, and an increase in the recombination of photo-generated electron–hole pairs. Pt modification led to a deterioration in the visible light photocatalytic activity of the material.

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