Band Gap Implications on Nano-TiO2 Surface Modification with Ascorbic Acid for Visible Light-Active Polypropylene Coated Photocatalyst

The effect of surface modification using ascorbic acid as a surface modifier of nano-TiO2 heterogeneous photocatalyst was studied. The preparation of supported photocatalyst was made by a specific paste containing ascorbic acid modified TiO2 nanoparticles used to cover Polypropylene as a support material. The obtained heterogeneous photocatalyst was thoroughly characterized (scanning electron microscope (SEM), RAMAN, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and Diffuse Reflectance Spectra (DRS) and successfully applied in the visible light photodegradation of Alizarin Red S in water solutions. In particular, this new supported TiO2 photocatalyst showed a change in the adsorption mechanism of dye with respect to that of only TiO2 due to the surface properties. In addition, an improvement of photocatalytic performances in the visible light photodegration was obtained, showing a strict correlation between efficiency and energy band gap values, evidencing the favorable surface modification of TiO2 nanoparticles.

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Facile Preparation of Efficient WO3Photocatalysts Based on Surface Modification

Journal of Nanomaterials ◽

10.1155/2015/502514 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Min Liu ◽

Hongmei Li ◽

Yangsu Zeng

Keyword(s):

Photocatalytic Activity ◽

Surface Modification ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Impregnation Method ◽

Light Spectra ◽

Simple Strategy ◽

Visible Light Active ◽

Efficient Charge ◽

Surface Modified

Tungsten trioxide (WO3) was surface modified with Cu(II) nanoclusters and titanium dioxide (TiO2) nanopowders by using a simple impregnation method followed by a physical combining method. The obtained nanocomposites were studied by scanning electron microscope, X-ray photoelectron spectroscopy spectra, UV-visible light spectra, and photoluminescence, respectively. Although the photocatalytic activity of WO3was negligible under visible light irradiation, the visible light photocatalytic activity of WO3was drastically enhanced by surface modification of Cu(II) nanoclusters and TiO2nanopowders. The enhanced photocatalytic activity is due to the efficient charge separation by TiO2and Cu(II) nanoclusters functioning as cocatalysts on the surface. Thus, this simple strategy provides a facile route to prepare efficient visible-light-active photocatalysts for practical application.

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VISIBLE LIGHT ACTIVE Cu2+/TiO2 NANOCATALYST FOR DEGRADATION OF DICHLORVOS

International Journal of Nanoscience ◽

10.1142/s0219581x12500305 ◽

2012 ◽

Vol 11 (05) ◽

pp. 1250030 ◽

Cited By ~ 3

Author(s):

TESHOME ABDO SEGNE ◽

SIVA RAO TIRUKKOVALLURI ◽

SUBRAHMANYAM CHALLAPALLI

Keyword(s):

Catalytic Activity ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Sol Gel ◽

Light Illumination ◽

X Ray ◽

Photo Catalytic Activity ◽

Visible Light Active ◽

Adsorption Desorption

The advantage of doping of TiO2 with copper has been utilized for enhanced degradation of pesticide under visible light irradiation. The sol–gel method has been undertaken for the synthesis of copper-doped TiO2 by varying the dopant loadings from 0.25 wt.% to 1.0 wt.% of Cu2+ . The doped samples were characterized by UV-Visible Diffuse Reflectance Spectroscopy (DRS), N2 adsorption–desorption (BET), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectrometry (EDS). The photocatalytic activity of the catalyst was tested by degradation of dichlorvos under visible light illumination. The results found that 0.75 wt.% of Cu2+ doped nanocatalysts have better photo catalytic activity than the rest of percentages doped, undoped TiO2 and Degussa P25. The reduction of band gap was estimated and the influence of the process parameters on photo catalytic activity of the catalyst has been explained.

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Enhanced Visible Light Photocatalytic Activity of Mesoporous AnataseTiO2Codoped with Nitrogen and Chlorine

International Journal of Photoenergy ◽

10.1155/2012/593245 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 9

Author(s):

Xiuwen Cheng ◽

Xiujuan Yu ◽

Zipeng Xing ◽

Lisha Yang

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Band Gap ◽

Light Absorption ◽

Photoelectron Spectroscopy ◽

Sol Gel ◽

Visible Region ◽

X Ray ◽

Visible Light Photocatalytic Activity ◽

Visible Light Photocatalytic

Anatase mesoporous titanium dioxide codoped with nitrogen and chlorine (N-Cl-TiO2) photocatalysts were synthesized through simple one-step sol-gel reactions in the presence of ammonium chloride. The resulting materials were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflection spectrum (UV-vis DRS). XRD results indicated that codoping with nitrogen and chlorine could effectively retard the phase transformation of TiO2from anatase to rutile and the growth of the crystallite sizes. XPS revealed that nitrogen and chlorine elements were incorporated into the lattice of TiO2through substituting the lattice oxygen atoms. DRS exhibited that the light absorption of N-Cl-TiO2in visible region was greatly improved. As a result, the band gap of TiO2was reduced to 2.12 eV. The photocatalytic activity of the as-synthesized TiO2was evaluated for the degradation of RhB and phenol under visible light irradiation. It was found that N-Cl-TiO2catalyst exhibited higher visible light photocatalytic activity than that of P25 TiO2and N-TiO2, which was attributed to the small crystallite size, intense light absorption in visible region, and narrow band gap.

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Silver/Carbon Codoped Titanium Dioxide Photocatalyst for Improved Dye Degradation under Visible Light

International Journal of Photoenergy ◽

10.1155/2017/3079276 ◽

2017 ◽

Vol 2017 ◽

pp. 1-9 ◽

Cited By ~ 12

Author(s):

P. Nyamukamba ◽

L. Tichagwa ◽

S. Mamphweli ◽

L. Petrik

Keyword(s):

Visible Light ◽

Band Gap ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance ◽

Diffuse Reflectance Spectroscopy ◽

Dye Degradation ◽

Rutile Phase ◽

X Ray Diffraction ◽

X Ray ◽

Hydrolysis Of

Herein, we report the synthesis of quartz supported TiO2 photocatalysts codoped with carbon and silver through the hydrolysis of titanium tetrachloride followed by calcination at 500°C. The prepared samples were characterized by UV-Vis diffuse reflectance spectroscopy, high resolution scanning electron microscopy (HRSEM), Raman spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Codoping of TiO2 with Ag and carbon resulted in an increase in the surface area of the photocatalyst and altered the ratio of the anatase to rutile phase. The absorption edge of all the doped TiO2 photocatalysts redshifted and the band gap was reduced. The lowest band gap of 1.95 eV was achieved by doping with 0.5% Ag. Doping TiO2 using carbon as the only dopant resulted in a quartz supported photocatalyst that showed greater photocatalytic activity towards methyl orange than undoped TiO2 and also all codoped TiO2 photocatalysts under visible light irradiation.

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A self-sacrifice template route to iodine modified BiOIO3: band gap engineering and highly boosted visible-light active photoreactivity

Physical Chemistry Chemical Physics ◽

10.1039/c5cp06685a ◽

2016 ◽

Vol 18 (11) ◽

pp. 7851-7859 ◽

Cited By ~ 24

Author(s):

Jingwen Feng ◽

Hongwei Huang ◽

Shixin Yu ◽

Fan Dong ◽

Yihe Zhang

Keyword(s):

Surface Modification ◽

Visible Light ◽

Band Gap ◽

Visible Light Photocatalysis ◽

Band Gap Engineering ◽

Visible Light Active

In this work we demonstrate the continuously adjustable band gap and visible-light photocatalysis activation of WBG BiOIO3via iodine surface modification.

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Synthesis of Oxygen Deficient TiO2 for Improved Photocatalytic Efficiency in Solar Radiation

Catalysts ◽

10.3390/catal11080904 ◽

2021 ◽

Vol 11 (8) ◽

pp. 904

Author(s):

Kassim Olasunkanmi Badmus ◽

Francois Wewers ◽

Mohammed Al-Abri ◽

Mohd Shahbaaz ◽

Leslie F. Petrik

Keyword(s):

Solar Radiation ◽

Visible Light ◽

Band Gap ◽

Tio2 Nanoparticles ◽

Energy Band ◽

High Energy ◽

Orange Ii ◽

Tio2 Photocatalyst ◽

Energy Band Gap ◽

Visible Light Active

The photocatalytic activities of TiO2 have been limited mainly to absorbing in the ultraviolet spectrum which accounts for only 5% of solar radiation. High energy band gap and electron recombination in TiO2 nanoparticles are responsible for its limitations as a photocatalyst. An oxygen deficient surface can be artificially created on the titanium oxide by zero valent nano iron through the donation of its excess electrons. A visible light active TiO2 nanoparticle was synthesized in the current investigation through simple chemical reduction using sodium boro-hydride. The physical and textural properties of the synthesized oxygen deficient TiO2 photocatalyst was measured using scanning/ transmission electron microscopy while FTIR, XRD and nitrogen sorption methods (BET) were employed for its further characterizations. Photochemical decoloration of orange II sodium dye solution in the presence of the synthesized TiO2 was measured using an UV spectrophotometer. The resulting oxygen deficient TiO2 has a lower energy band-gap, smaller pore sizes, and enhanced photo-catalytic properties. The decoloration (88%) of orange (II) sodium salt solution (pH 2) under simulated solar light was possible at 20 min. This study highlights the effect of surface oxygen defects, crystal size and energy band-gap on the photo-catalytical property of TiO2 nanoparticles as impacted by nano zero valent iron. It opens a new window in the exploitation of instability in the dopant ions for creation of a visible light active TiO2 photocatalyst.

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The Photocatalytic Degradation of Vehicle Exhausts by an Fe/N/Co–TiO2 Waterborne Coating under Visible Light

Materials ◽

10.3390/ma12203378 ◽

2019 ◽

Vol 12 (20) ◽

pp. 3378 ◽

Cited By ~ 4

Author(s):

Huiyun Xia ◽

Guanyu Liu ◽

Rui Zhang ◽

Lifang Song ◽

Huaxin Chen

Keyword(s):

Visible Light ◽

Tio2 Nanoparticles ◽

Photoelectron Spectroscopy ◽

Alkali Resistance ◽

Vehicle Exhaust ◽

Exposure Test ◽

Pencil Hardness ◽

Tio2 Nps ◽

X Ray ◽

Degradation Rates

Based on the three-dimensional network structure of a polymer and the principle of photocatalysts, a visible-light-responsive and durable photocatalytic coating for the degradation of vehicle exhaust (VE) has been constructed using a waterborne acrylic acid emulsion as the coating substrate; Fe/N/Co–TiO2 nanoparticles (NPs) as photocatalytic components; and water, pigments, and fillers as additives. The visible-light-responsive Fe/N/Co–TiO2 NPs with an average size of 100 nm were prepared by sol-gel method firstly. The co-doping of three elements extended the absorption range of the modified TiO2 nanoparticles to the visible light region, and showed the highest light absorption intensity, which was confirmed by the ultraviolet-visible absorption spectra (UV-Vis). X-ray diffraction (XRD) measurements showed that element doping prevents the transition from anatase to rutile and increases the transition temperature. TiO2 was successfully doped due to the reduction of the chemical binding energy of Ti, as revealed by X-ray photoelectron spectroscopy (XPS). The degradation rates of NOX, CO, and CO2 in VE by Fe/N/Co–TiO2 NPs under visible light were 71.43%, 23.79%, and 21.09%, respectively. In contrast, under the same conditions, the degradation efficiencies of coating for VE decreased slightly. Moreover, the elementary properties of the coating, including pencil hardness, adhesive strength, water resistance, salt, and alkali resistance met the code requirement. The photocatalytic coating exhibited favorable reusability and durability, as shown by the reusability and exposure test.

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Cu2O–TiO2 Composite for Photocatalytic Degradation of Benzene and its derivatives Using Visible Light

Current Nanoscience ◽

10.2174/1573413717666210127102749 ◽

2021 ◽

Vol 17 ◽

Author(s):

Satya Vijaya Kumar Nune ◽

Ravi Kumar Golimidi

Keyword(s):

Visible Light ◽

Photocatalytic Degradation ◽

Band Gap ◽

Tio2 Nanoparticles ◽

Uv Light ◽

High Surface ◽

High Surface Area ◽

Visible Region ◽

Copper Ion ◽

Visible Light Active

Background: Heterostructured nanocomposites have gained huge attention for their catalytic properties lately. A wide array of different visible-light-active photocatalysts (VLAPs) have been extensively studied of the past couple of years to fine tune the band gap of various stable semiconductors. Objective: The current investigation reports the sensitization of TiO2 nanoparticles with nano sized cuprous oxide, a wellstudied p-type semiconductor, which has a relatively narrow band gap ranging between 2.1 eV & 2.6 eV, to obtain a visible light active photocatalyst. Methods: visible-light-active Cu2O–TiO2 nanocomposite synthesized using solvo-thermal technique. The nanocomposite’s structure and size properties were studied using powder diffraction (XRD), electron microscopy (FESEM and HRTEM). Cu2O–TiO2 nanocomposite was tested on benzene, toluene and chlorobenzene in contaminated water, under UV and under visible light, for effective implementation in photocatalytic degradation of volatile organic contaminants. Results: The said nanocomposite was crystalline and found to be 40–50 nm in size. No apparent change in the crystal lattice of TiO2 was observed due to the introduction of copper ion, and the nanocomposite also retained high surface area of 76.28 m2 /g. The efficiency of the Cu2O-TiO2 nanoparticles degradation is studied both under UV light and under visible. Cu2O-TiO2 nanoparticles have achieved 97 – 99% degradation of benzene, 92 – 97% degradation of toluene and 95 – 98% degradation of chlorobenzene in water. Conclusion: The said Cu2O–TiO2 nanocomposite is photo-active and showed an overall 95% degradation within 2 hours of treatment under the visible region.

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Synthesis and Optimization of Visible Light Active BiVO4Photocatalysts for the Degradation of RhB

International Journal of Photoenergy ◽

10.1155/2015/612857 ◽

2015 ◽

Vol 2015 ◽

pp. 1-14 ◽

Cited By ~ 13

Author(s):

Rong Ran ◽

Joanne Gamage McEvoy ◽

Zisheng Zhang

Keyword(s):

Visible Light ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance ◽

Reflectance Spectrophotometry ◽

X Ray Diffraction ◽

X Ray ◽

Visible Light Range ◽

Excellent Photocatalytic Activity ◽

Visible Light Active ◽

Uv Visible

Monoclinic BiVO4powders were synthesized via a novel route using potassium metavanadate (KVO3) prepared by calcination of K2CO3and V2O5as a starting material and followed by hydrothermal treatment and were investigated for the degradation of Rhodamine B (RhB) under visible light irradiation. The synthesized BiVO4particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-Visible (UV-Vis) light diffuse reflectance spectrophotometry. The synthesis produced pure monoclinic BiVO4particles with multimorphological features containing flower-like, flake-ball, flake, cuboid-like, and plate-like shapes and exhibited strong absorption in the visible light range. The BiVO4prepared via KVO3possessed excellent photocatalytic activity for the degradation of RhB under visible light. The performance of this catalyst was found to be superior to other BiVO4photocatalysts prepared via ammonium metavanadate (NH4VO3) using coprecipitation, combustion, and calcination methods reported in literature, respectively.

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