Preparation of Visible Light Responsive Photocatalyst from Titanium Dioxide Nanotubes Modified with Antimony Trisulfide

Titanium dioxide (TiO2) nanotubes with a highly ordered structure were grown by a self-organized anodization process. The photodeposition process was used to improve the visible light response of titanium dioxide (TiO2) nanotubes. The irradiation was carried out with 500 W halogen lamp for 1, 5, 15, 30 and 60 min in the mixed ethanol solution of antimony trisulfide (Sb2S3). The obtained samples were annealed at 250 °C for 30 min. The morphology of the fabricated sample was characterized by a field emission scanning electron microscope (FE-SEM). The phase of samples was determined by X- ray diffractometer (XRD). The weight percentages of a component in the sample were measured by X-ray fluorescence spectrometry (XRF). UV-Vis diffuse reflectance spectra (DRS) of the samples were recorded. All titanium dioxide (TiO2) nanotube samples prepared by anodization process were anatase phase. All composite titanium dioxide (TiO2) nanotube /Sb2S3samples were a crystalline phase. The percentage of Sb and S increase with increasing of photodeposition’s time. The increasing photodeposition of antimony trisulfide (Sb2S3) on titanium (TiO2) nanotubes from 1 to 60 min lead to increasing of photoabsorption property of the material in the visible region.

Download Full-text

Visible Light Induced Photocatalytic Degradation of Methyl Red with Codoped Titania

Journal of Catalysts ◽

10.1155/2014/962419 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Susmitha Thota ◽

Siva Rao Tirukkovalluri ◽

Sreedhar Bojja

Keyword(s):

Visible Light ◽

Photocatalytic Degradation ◽

Anatase Phase ◽

Sol Gel ◽

Visible Region ◽

Oxygen Demand ◽

Analytical Techniques ◽

Active Species ◽

Methyl Red ◽

X Ray

Photocatalysis using semiconductor oxides was being investigated extensively for the degradation of dyes in effluent water. This paper reports our findings on visible light induced photocatalytic degradation of azo dye, methyl red mediated nitrogen and manganese codoped nano-titanium dioxide (N/Mn-TiO2). The codoped samples with varying weight percentages were synthesized by sol-gel method and characterized by various analytical techniques. The X-ray diffraction data showed that the synthesized samples were in anatase phase with 2θ at 25.3°. UV-visible diffuse reflectance spectral analysis revealed that the presence of dopants in TiO2 caused a significant absorption shift towards visible region and their presence was confirmed by X-ray photoelectron spectral data. The release of hydroxyl radical (major active species in photocatalytic degradation) by the photocatalyst in aqueous solution under visible light irradiation was quantitatively investigated by the photoluminiscent technique (PL). The effect of various experimental parameters like dopant concentration, pH, catalyst dosage, and initial dye concentrations was investigated and optimum conditions were established. The extent of mineralization of methyl red was studied by chemical oxygen demand (COD) assays and the results showed complete mineralization of the dye.

Download Full-text

SYNTHESIS OF MESOPOROUS OF NyTi1–xCexO2–y STRUCTURES AND ITS VISIBLE LIGHT INDUCED PHOTOCATALYTIC PERFORMANCE

NANO ◽

10.1142/s1793292013500513 ◽

2013 ◽

Vol 08 (05) ◽

pp. 1350051 ◽

Cited By ~ 3

Author(s):

R. RANGEL ◽

J. D. GARCÍA-ESPINOZA ◽

I. ESPITIA ◽

P. QUINTANA ◽

P. BARTOLO-PÉREZ ◽

...

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance ◽

Anatase Phase ◽

Visible Region ◽

Textural Properties ◽

Band Gap Energy ◽

X Ray ◽

Xrd Diffraction

The present work was addressed to study the visible light induced performance as photocatalysts of mesoporous N y Ti 1–x Ce x O 2–y structures obtained under microwave irradiation. The titanium dioxide ( TiO 2) was doped with cerium and nitrogen in order to improve the quantum efficiency of the TiO 2 and to shift its adsorption spectra to the visible region. The prepared meso-powders were analyzed by means of X-ray diffraction (XRD), scanning Electron microscopy (SEM), infrared (IR) spectroscopy, transmission electronic microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The surface area was evaluated by means of the Brunauer-Emmett-Teller (BET) method and ultraviolet (UV)-visible diffuse reflectance measurements were performed in order to determine the band gap energy. In addition, the photocatalytic activity of the samples was evaluated by monitoring the photodegradation of methylene blue (MB) under UV and visible light energy irradiation. The results show that our methodology is an effective way for incorporating cerium and nitrogen into TiO 2 compound, which in turn, increases its photocatalytic activity. The diffuse reflectance analysis confirms that the absorption edge was shifted towards the visible region of the optical spectrum. The XRD diffraction patterns indicate homogeneous solid solutions in which prevails the anatase phase. It was observed a reduction in crystal size from 13.1 nm to 7.7 nm for N y Ti 0.98 Ce 0.02 O 2–y in comparison to TiO 2. The textural properties of the synthesized compounds were determined, by means of adsorption isotherms indicating the formation of mesoporous structures. IR spectra show characteristic vibration signals attributed to Ti–O–Ti bonds, as well as vibrations assigned to cerium and nitrogen bonds. The XPS analyses evidence the presence of Ce 3+/ Ce 4+ redox couple and Ti–N bonds. The photocatalityc efficiency was evaluated in the degradation of MB monitoring the absorbance change at 664 nm. The degradation of this compound was 91.4% using N y Ti 0.98 Ce 0.02 O 2–y as photocatalyst under UV energy in 90 min. Also 38.7% of MB degradation was achieved in 150 min under visible light radiation.

Download Full-text

Enhancement of Visible Light-Responsive Photocatalytic Efficiency by Using a Laccaic Acid-Modified Titanium Dioxide Photocatalyst

Journal of the Brazilian Chemical Society ◽

10.21577/0103-5053.20220006 ◽

2022 ◽

Author(s):

Montri Aiempanakit ◽

Jariyaporn Sangkaworn ◽

Nattawan Worawannotai ◽

Kritapas Laohhasurayotin ◽

Weerachai Sangchay ◽

...

Keyword(s):

Visible Light ◽

Anatase Phase ◽

Visible Region ◽

Nitrogen Adsorption ◽

Hydroxyl Groups ◽

Impregnation Method ◽

Sem Images ◽

Tio2 Sample ◽

X Ray ◽

Xrd Patterns

In this study, a laccaic acid-modified TiO2 photocatalyst (Lac-TiO2) was prepared via an impregnation method with 0.50, 1.00, 2.50, and 5.00 wt.% laccaic acid. The products’ physical properties were examined through X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoemission spectroscopy (XPS), UV-Vis diffused reflectance spectroscopy (DRS), Fourier-transform infrared spectroscopy (FTIR), nitrogen adsorption/desorption, and photoluminescence (PL) spectroscopy. A possible photocatalytic mechanism was also proposed. XRD patterns revealed the anatase phase of TiO2 and Lac-TiO2 samples. High-magnification FE-SEM images showed that the TiO2 and Lac-TiO2 samples exhibited spherical-like structures. XPS results complementarily confirmed the presence of Ti, O, and C as the main elements of the Lac-TiO2 samples. Interestingly, the DRS spectra of the Lac-TiO2 samples extended into the visible region. FTIR spectra presented the characteristic bands of TiO2 and hydroxyl groups on the TiO2 surface. Instead of hydroxyl groups, the characteristic bands of laccaic acid were observed on the surface of the Lac-TiO2 samples. The photocatalytic properties of the Lac-TiO2 samples were evaluated in terms of methyl orange degradation under visible light irradiation. The Lac-TiO2 samples showed higher photocatalytic performance than the TiO2 sample.

Download Full-text

Cu Doped TiO2: Visible Light Assisted Photocatalytic Antimicrobial Activity and High Temperature Anatase Stability

10.26434/chemrxiv.7159733.v1 ◽

2018 ◽

Cited By ~ 2

Author(s):

Snehamol Mathew ◽

Priyanka Ganguly ◽

Stephen Rhatigan ◽

Vignesh Kumaravel ◽

Ciara Byrne ◽

...

Keyword(s):

Visible Light ◽

Visible Light Irradiation ◽

Density Functional ◽

Anatase Phase ◽

Sol Gel ◽

Chemical Properties ◽

Light Irradiation ◽

Health Concern ◽

Bacterial Inactivation ◽

X Ray

Indoor surface contamination by microbes is a major public health concern. A damp environment is one potential sources for microbe proliferation. Smart photocatalytic coatings on building surfaces using semiconductors like titania (TiO2) can effectively curb this growing threat. Metal-doped titania in anatase phase has been proved as a promising candidate for energy and environmental applications. In this present work, the antimicrobial efficacy of copper (Cu) doped TiO2 (Cu-TiO2) was evaluated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) under visible light irradiation. Doping of a minute fraction of Cu (0.5 mol %) in TiO2 was carried out via sol-gel technique. Cu-TiO2 further calcined at various temperatures (in the range of 500 °C – 700 °C) to evaluate the thermal stability of TiO2 anatase phase. The physico-chemical properties of the samples were characterised through X-ray diffraction (XRD), Raman spectroscopy, X-ray photo-electron spectroscopy (XPS) and UV-visible spectroscopy techniques. XRD results revealed that the anatase phase of TiO2 was maintained well, up to 650 °C, by the Cu dopant. UV-DRS results suggested that the visible light absorption property of Cu-TiO2 was enhanced and the band gap is reduced to 2.8 eV. Density functional theory (DFT) studies emphasises the introduction of Cu+ and Cu2+ ions by replacing Ti4+ ions in the TiO2 lattice, creating oxygen vacancies. These further promoted the photocatalytic efficiency. A significantly high bacterial inactivation (99.9%) was attained in 30 mins of visible light irradiation by Cu-TiO2.

Download Full-text

The Photocatalytic and Antibacterial Performance of Nitrogen-Doped TiO2: Surface-Structure Dependence and Silver-Deposition Effect

Nanomaterials ◽

10.3390/nano10112261 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2261 ◽

Cited By ~ 2

Author(s):

Abdul Wafi ◽

Erzsébet Szabó-Bárdos ◽

Ottó Horváth ◽

Mihály Pósfai ◽

Éva Makó ◽

...

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Surface Area ◽

Photocatalytic Performance ◽

Visible Region ◽

Bet Surface Area ◽

Doped Tio2 ◽

X Ray ◽

Nitrogen Doped ◽

Visible Light Driven

Catalysts for visible-light-driven oxidative cleaning processes and antibacterial applications (also in the dark) were developed. In order to extend the photoactivity of titanium dioxide into the visible region, nitrogen-doped TiO2 catalysts with hollow and non-hollow structures were synthesized by co-precipitation (NT-A) and sol–gel (NT-U) methods, respectively. To increase their photocatalytic and antibacterial efficiencies, various amounts of silver were successfully loaded on the surfaces of these catalysts by using a facile photo-deposition technique. Their physical and chemical properties were evaluated by using scanning electron microscopy (SEM), transmission electron microscopy–energy dispersive X-ray spectroscopy (TEM–EDS), Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction (XRD), and diffuse reflectance spectra (DRS). The photocatalytic performances of the synthesized catalysts were examined in coumarin and 1,4-hydroquinone solutions. The results showed that the hollow structure of NT-A played an important role in obtaining high specific surface area and appreciable photoactivity. In addition, Ag-loading on the surface of non-hollow structured NT-U could double the photocatalytic performance with an optimum Ag concentration of 10−6 mol g−1, while a slight but monotonous decrease was caused in this respect for the hollow surface of NTA upon increasing Ag concentration. Comparing the catalysts with different structures regarding the photocatalytic performance, silverized non-hollow NT-U proved competitive with the hollow NT-A catalyst without Ag-loading for efficient visible-light-driven photocatalytic oxidative degradations. The former one, due to the silver nanoparticles on the catalyst surface, displayed an appreciable antibacterial activity, which was comparable to that of a reference material practically applied for disinfection in polymer coatings.

Download Full-text

One-Pot Hydrothermal Synthesis of Sulfur-Doped SnO2 Nanoparticles and their Enhanced Photocatalytic Properties

NANO ◽

10.1142/s1793292016500351 ◽

2016 ◽

Vol 11 (03) ◽

pp. 1650035 ◽

Cited By ~ 6

Author(s):

Lin Ma ◽

Limei Xu ◽

Xuyao Xu ◽

Xiaoping Zhou ◽

Lingling Zhang

Keyword(s):

Visible Light ◽

Photoelectron Spectroscopy ◽

Electrochemical Impedance ◽

Sno2 Nanoparticles ◽

Light Response ◽

One Pot ◽

X Ray ◽

Transmission Electron ◽

Light Region ◽

Vis Spectroscopy

Sulfur-doped SnO2 nanoparticles with ultrafine sizes have been successfully prepared by a one-pot hydrothermal method. The obtained samples are characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM), thermogravimetric (TG), analyzer UV-Vis spectroscopy, photoluminescence (PL) and electrochemical impedance spectroscopy (EIS). The experimental results indicate that the doping level of sulfur element as well as the bandgaps of SnO2 can be controlled to a certain extent by varying the amount of L-cysteine (L-cys). When evaluated as photocatalysts in the degradation of rhodamine B (RhB) and reduction of Cr(VI) under visible light region, the resultant sulfur-doped SnO2 nanoparticles demonstrate obviously enhanced photocatalytic activities due to the markedly improved visible light response and effective separation of the photo-generated electron–hole pairs.

Download Full-text

Preparation of Fe-DopedTiO2Nanotubes and Their Photocatalytic Activities under Visible Light

International Journal of Photoenergy ◽

10.1155/2013/981753 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 6

Author(s):

Honghui Teng ◽

Shukun Xu ◽

Dandan Sun ◽

Ying Zhang

Keyword(s):

Visible Light ◽

Visible Region ◽

Molar Ratio ◽

X Ray Diffraction ◽

Visible Absorption ◽

X Ray ◽

Transmission Electron ◽

Photocatalytic Activities ◽

Ultrasonic Assisted ◽

Uv Visible

Fe-doped TiO2nanotubes (Fe-TNTs) have been prepared by ultrasonic-assisted hydrothermal method. The structure and composition of the as-prepared TiO2nanotubes were characterized by transmission electron microscopy, X-ray diffraction, and UV-Visible absorption spectroscopy. Their photocatalytic activities were evaluated by the degradation of MO under visible light. The UV-visible absorption spectra of the Fe-TNT showed a red shift and an enhancement of the absorption in the visible region compared to the pure TNT. The Fe-TNTs were provided with good photocatalytic activities and photostability and under visible light irradiation, and the optimum molar ratio of Ti : Fe was found to be 100 : 1 in our experiments.

Download Full-text

Extension of the Optical Absorption of TiO2 Nanopaticles to Visible Light Region by Doping with Cobalt

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.181-182.348 ◽

2011 ◽

Vol 181-182 ◽

pp. 348-351

Author(s):

Yi Ding ◽

Xiao Jun Xu ◽

Zhang Hua Gan ◽

Rui Xiong ◽

Hai Lin Liu

Keyword(s):

Optical Absorption ◽

Visible Light ◽

Light Absorption ◽

Anatase Phase ◽

Electron Transition ◽

Binding Energies ◽

Visible Absorption ◽

Visible Light Absorption ◽

X Ray ◽

Light Region

TiO2 nanoparticles doped with different cobalt concentrations were fabricated by using so-gel method. The crystal structures and the morphology of the samples were characterized by using x-ray diffractmetry (XRD) and transmission electron microscopy (TEM), respectively. It was found that all the samples are anatase phase and the nanoparticles are of the size around 10 nm. Investigations of the binding energies of different element with X-ray photoelectron spectrometry (XPS) revealed that Co ions are in Co2+ state and take the substitutional sites. No Co clusters were detected in the samples. The optical absorption properties of the samples were studied by using UV-vis absorption spectroscopy. It was noticed that cobalt doped TiO2 has a significant visible light absorption in contrast to pure TiO2: besides a noticeable red shift in absorption edge, an extra visible light absorption peak appears at a wavelength around 600 nm. The visible absorption in cobalt doped TiO2 may attribute to the electron transition from impurity levels induced by the substitutional Co ions and the oxygen vacancies to the conduct band.

Download Full-text

Photocatalytic Activity of Sol-Gel Derived Bi2O3-TiO2 Nanocomposite

Materials Science Forum ◽

10.4028/www.scientific.net/msf.712.73 ◽

2012 ◽

Vol 712 ◽

pp. 73-83 ◽

Cited By ~ 1

Author(s):

C. Karunakaran ◽

P. Magesan ◽

P. Gomathisankar

Keyword(s):

Visible Light ◽

Deep Level ◽

Anatase Phase ◽

Sol Gel ◽

Spherical Shape ◽

Tween 80 ◽

Electron Microscopic ◽

Sem Images ◽

X Ray ◽

Crystallite Sizes

Bi2O3-TiO2 nanocomposites were obtained by sol-gel method using tween 80 (T-80) or polyvinyl pyrrolidone-polyethylene glycol (PVP-PEG) as templating agent. The powder X-ray diffraction (XRD) patterns of both the composites reveal the crystal structure of Bi2O3 as primitive tetragonal and TiO2 is in anatase phase. The energy dispersive X-ray (EDX) spectra provide the composition of Bi2O3 in Bi2O3-TiO2 (T-80) and Bi2O3-TiO2 (PVP-PEG) as 3.8 and 20.4 mol. %, respectively. The average crystallite sizes of Bi2O3-TiO2 (T-80) and Bi2O3-TiO2 (PVP-PEG), derived from XRD, are 9 and 17 nm, respectively. The scanning electron microscopic (SEM) images show the spherical shape of Bi2O3-TiO2 (T-80) and the composites are polycrystalline. The diffuse reflectance spectra (DRS) of the composites display faint absorption of visible light and strong absorption in UV-A region. The photoluminescence (PL) spectra of both the composites are similar and the observed near band gap emission (NBE) and deep level emission (DLE) agree with those of TiO2. The impedance spectra show that the charge-transfer resistances of the composites do not differ significantly. The visible light photoimpedance spectra display the photoconductance of Bi2O3-TiO2 (PVP-PEG) but not that of Bi2O3-TiO2 (T-80). Although the visible light-photocatalytic activities of the two nanocomposites to degrade dye do not differ significantly Bi2O3-TiO2 (T-80) under UV-A light degrades dyes faster than Bi2O3-TiO2 (PVP-PEG).

Download Full-text

Photoreactive Carbon and Nitrogen-Codoped ZnWO4 Nanoparticles: Synthesis and Reactivity

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.621.172 ◽

2012 ◽

Vol 621 ◽

pp. 172-177 ◽

Cited By ~ 1

Author(s):

Su Hua Chen ◽

Bi Xuan Wang ◽

Xian Hua Qiu ◽

Zhen Sheng Xiong

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Visible Region ◽

Weight Ratio ◽

Morphological Properties ◽

X Ray Diffraction ◽

Visible Spectroscopy ◽

X Ray ◽

Carbon And Nitrogen ◽

Uv Visible

In order to improve ZnWO4 photocatalytic activity under visible light, the C, N-codoped ZnWO4 nanoparticles have been successfully synthesized by choosing C3N4 generated from tripolycyanamide pyrolysis as the source of Carbon and Nitrogen and the influence of C3N4 concentration on structural, optical and morphological properties of C, N-codoped ZnWO4 using X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscopy (SEM) and photocatalytic decoloration of rhodamine B (RhB) aqueous solution under visible light. It was found that the presence of carbon and nitrogen could not improve the crystallization of ZnWO4 species but could enhance their photoabsorption property in the visible region. The results also showed that the photocatalytic activity of the as-prepared ZnWO4 is higher than that of pure ZnWO4 with the optimum effect occurring at RC3N4 = 9 % (the weight ratio of tripolycyanamide to ZnWO4)

Download Full-text