Visible-light photocatalytic activity and recyclability of N-doped TiO2 films grown by MOCVD

Abstract Nitrogen-doped TiO2 films were grown on borosilicate glass substrates at 400 °C by the metallorganic chemical vapor deposition (MOCVD) for removing dye from water under visible light. The effect of N-doping on the structural, surface, and photocatalytic properties of films was evaluated. X-ray photoelectron spectroscopy (XPS) analyses revealed that 1.56 and 2.44 at% of nitrogen were incorporated into the films by varying the NH3 flux during the growth. Methyl orange dye degradation experiments showed that the N-doped films presented photoactivity under visible light. The film containing 2.44 at% of nitrogen exhibited the best photocatalytic behavior, with 55% of efficiency. Recyclability tests under visible light showed that the film efficiency dropped gradually after each test. N-TiO2 films grown by MOCVD have the potential to be used in environmental applications by removing pollutants using a green method under sunlight or even under internal illumination, although its reuse is limited.

Download Full-text

FeYO3@rGO nanocomposites: Synthesis, characterization and application in photooxidative degradation of atrazine under visible light

Materials Express ◽

10.1166/mex.2021.1957 ◽

2021 ◽

Vol 11 (5) ◽

pp. 706-716

Author(s):

Nada D. Al-Khthami ◽

Tariq Altalhi ◽

Mohammed Alsawat ◽

Mohamed S. Amin ◽

Yousef G. Alghamdi ◽

...

Keyword(s):

Visible Light ◽

Photoelectron Spectroscopy ◽

Sol Gel ◽

Bandgap Energy ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Reduced Graphene ◽

Structural Surface ◽

Adsorption Desorption

Different organic pollutants have been remediated photo catalytically by applying perovskite photocatalysts. Atrazine (ATR) is a pesticide commonly detected as a pollutant in drinking, surface and ground water. Herein, FeYO3@rGO heterojunction was synthesized and applied for photooxidation decomposition of ATR. First, FeYO 3nanoparticles (NPs) were prepared via routine sol-gel. After that, FeYO3 NPs were successfully incorporated with different percentages (5, 10, 15 and 20 wt.%) of reduced graphene oxide (rGO) in the synthesis of novel FeYO3@rGO photocatalyst. Morphological, structural, surface, optoelectrical and optical characteristics of constructed materials were identified via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), adsorption/desorption isotherms, diffusive reflectance (DR) spectra, and photoluminescence response (PL). Furthermore, photocatalytic achievement of the constructed materials was evaluated via photooxidative degradation of ATR. Various investigations affirmed the usefulness of rGO incorporation on the advancement of formed photocatalysts. Actually, novel nanocomposite containing rGO (15 wt.%) possessed diminished bandgap energy, as well as magnified visible light absorption. Furthermore, such nanocomposite presented exceptional photocatalytic achievement when exposed to visible light as ATR was perfectly photooxidized over finite amount (1.6 g · L-1) from the optimized photocatalyst when illuminated for 30 min. The advanced photocatalytic performance of constructed heterojunctions could be accredited mainly to depressed recombination amid induced charges. The constructed FeYO3@rGO nanocomposite is labelled as efficient photocatalyst for remediation of herbicides from aquatic environments.

Download Full-text

Ferromagnetic Properties of N-Doped and Undoped TiO2 Rutile Single-Crystal Wafers with Addition of Tungsten Trioxide

Materials ◽

10.3390/ma11101934 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1934 ◽

Cited By ~ 1

Author(s):

Jing Xu ◽

Haiying Wang ◽

Zhongpo Zhou ◽

Zhaorui Zou

Keyword(s):

Magnetic Properties ◽

Single Crystal ◽

Saturation Magnetization ◽

Photoelectron Spectroscopy ◽

Oxygen Vacancies ◽

Tio2 Surface ◽

Doped Tio2 ◽

X Ray ◽

N Doping ◽

Tio2 Rutile

In this work, undoped, N-doped, WO3-loaded undoped, and WO3-loaded with N-doped TiO2 rutile single-crystal wafers were fabricated by direct current (DC) magnetron sputtering. N-doping into TiO2 and WO3 loading onto TiO2 surface were used to increase and decrease oxygen vacancies. Various measurements were conducted to analyze the structural and magnetic properties of the samples. X-ray diffraction results showed that the N-doping and WO3 loading did not change the phase of all samples. X-ray photoelectron spectroscopy results revealed that W element loaded onto rutile single-crystal wafers existed in the form of WO3. UV-Vis spectrometer results showed that the absorption edge of WO3-loaded undoped and WO3-loaded with N-doped TiO2 rutile single-crystal wafers had red shift, resulting in a slight decrease in the corresponding band gap. Photoluminescence spectra indicated that oxygen vacancies existed in all samples due to the postannealing atmosphere, and oxygen vacancies density increased with N-doping, while decreasing with WO3 loading onto TiO2 surface. The magnetic properties of the samples were investigated, and the saturation magnetization values were in the order N-doped > WO3-loaded with N-doped > undoped > WO3-loaded undoped rutile single-crystal wafers, which was the same order as the oxygen vacancy densities of these samples. N-doping improved the saturation magnetization values, while WO3-loaded decreased the saturation magnetization values. This paper reveals that the magnetic properties of WO3-loaded with N-doped rutile single-crystal wafers originate from oxygen vacancies.

Download Full-text

Synthesis of Hollow Flower-Like Fe3O4/MnO2/Mn3O4 Magnetically Separable Microspheres with Valence Heterostructure for Dye Degradation

Catalysts ◽

10.3390/catal9070589 ◽

2019 ◽

Vol 9 (7) ◽

pp. 589 ◽

Cited By ~ 4

Author(s):

Mingliang Ma ◽

Yuying Yang ◽

Yan Chen ◽

Fei Wu ◽

Wenting Li ◽

...

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Organic Contaminants ◽

Dye Degradation ◽

Catalytic Performance ◽

X Ray ◽

Composite Microspheres ◽

Magnetically Separable ◽

Mno2 Nanosheet

In this manuscript, hollow flower-like ferric oxide/manganese dioxide/trimanganese tetraoxide (Fe3O4/MnO2/Mn3O4) magnetically separable microspheres were prepared by combining a simple hydrothermal method and reduction method. As the MnO2 nanoflower working as precursor was partially reduced, Mn3O4 nanoparticles were in situ grown from the MnO2 nanosheet. The composite microspheres were characterized in detail by employing scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), vibration sample magnetometer (VSM) and UV–visible spectrophotometer (UV–vis). Under visible light conditions, the test for degrading rhodamine B (RhB) was used to verify the photocatalytic activity of the photocatalyst. The results showed that the efficiency of the Fe3O4/MnO2/Mn3O4 photocatalyst in visible light for 130 min is 94.5%. The catalytic activity of photocatalyst far exceeded that of the Fe3O4/MnO2 component, and after four cycles, the catalytic performance of the catalyst remained at 78.4%. The superior properties of the photocatalyst came from improved surface area, enhanced light absorption, and efficient charge separation of the MnO2/Mn3O4 heterostructure. This study constructed a green and efficient valence heterostructure composite that created a promising photocatalyst for degrading organic contaminants in aqueous environments.

Download Full-text

Liquid-phase non-thermal plasma-prepared N-doped TiO2 for azo dye degradation with the catalyst separation system by ceramic membranes

Water Science & Technology ◽

10.2166/wst.2010.334 ◽

2010 ◽

Vol 62 (5) ◽

pp. 1060-1066 ◽

Cited By ~ 3

Author(s):

Hsu-Hui Cheng ◽

Shiao-Shing Chen ◽

Yi-Wen Cheng ◽

Wei-Lun Tseng ◽

Yi-Hui Wang

Keyword(s):

Photocatalytic Activity ◽

Liquid Phase ◽

Thermal Plasma ◽

Membrane Separation ◽

Dye Degradation ◽

Ceramic Membranes ◽

Doped Tio2 ◽

Vis Spectroscopy ◽

N Doping ◽

Non Thermal Plasma

This study strived to improve the photocatalytic activity by using liquid-phase non-thermal plasma (LPNTP) technology for preparing N-doping TiO2 as well as to separate/recover the N-dope TiO2 particles by using ceramic ultrafiltration membrane process. The yellow color N-doped TiO2 photocatalysts, obtained through the LPNTP process, were characterized with UV–Vis spectroscopy, X-ray diffraction (XRD), and electron spectroscopy for chemical analysis (ESCA). The UV–Vis spectrum of N-doped TiO2 showed that the absorption band was shifted to 439 nm and the band gap was reduced to 2.82 eV. The structure analysis of XRD spectra showed that the peak positions and the crystal structure remained unchanged as anatase after plasma-treating at 13.5 W for 40 min. The photocatalytic activity of N-doped TiO2 was evaluated by azo dyes under visible light, and 63% of them was degraded after 16 hours in a continuous-flow photocatalytic system. For membrane separation/recover system, the recovery efficiency reached 99.5% after the ultrafiltration had been carried out for 90 min, and the result indicated that the photocatalyst was able to be separated/recovered completely.

Download Full-text

Origin of visible-light sensitivity in N-doped TiO2 films

Chemical Physics ◽

10.1016/j.chemphys.2007.05.031 ◽

2007 ◽

Vol 339 (1-3) ◽

pp. 20-26 ◽

Cited By ~ 46

Author(s):

Yoshitaka Nakano ◽

Takeshi Morikawa ◽

Takeshi Ohwaki ◽

Yasunori Taga

Keyword(s):

Visible Light ◽

Light Sensitivity ◽

Tio2 Films ◽

Doped Tio2

Download Full-text

The Biocompatibility of Ti Alloy Improved by Nitrogen-Doped Diamond-Like Carbon Films

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.711.250 ◽

2014 ◽

Vol 711 ◽

pp. 250-254 ◽

Cited By ~ 1

Author(s):

Wufanbieke Baheti ◽

Ming Xin Li ◽

Fu Guo Wang ◽

Jin Ge Song ◽

Long Hua Xu ◽

...

Keyword(s):

Contact Angle ◽

Photoelectron Spectroscopy ◽

Carbon Film ◽

Chemical Vapor ◽

Carbon Films ◽

Diamond Like Carbon ◽

Measuring Device ◽

Nitrogen Doped ◽

Angle Measuring ◽

N Doping

The nitrogen-doped diamond-like carbon film was prepared on Ti6Al4V alloy by using plasma enhanced chemical vapor deposition (PECVD) technique,and its biocompatibility was studied.The surface morphology,chemical composition and contact angle were measured by scanning electron microscope (SEM),X-ray photoelectron spectroscopy(XPS),Raman Spectrometer and contact angle measuring device. Finally, the proliferation rate and cellular morphology of 3T3-E1 osteoblast cells on different sample surfaces were tested and Image J software was used to statistically analyze the count of the adhered cells. The results showed that cell adhesion and proliferation were significantly (P<0.05) increased on nitrogen-doped diamond-like carbon films , which illustrated that N doping improved the biocompatibility of DLC films. This finding has potential clinical application value to modify titanium alloy for new bone formation.

Download Full-text

Origin of visible-light activity of N-doped TiO2 photocatalyst: Behaviors of N and S atoms in a wet N-doping process

Applied Catalysis B Environmental ◽

10.1016/j.apcatb.2012.06.034 ◽

2012 ◽

Vol 128 ◽

pp. 77-83 ◽

Cited By ~ 41

Author(s):

Taizo Sano ◽

Nobuaki Mera ◽

Yusuke Kanai ◽

Chifumi Nishimoto ◽

Sakiko Tsutsui ◽

...

Keyword(s):

Visible Light ◽

Tio2 Photocatalyst ◽

Doped Tio2 ◽

Light Activity ◽

N Doping

Download Full-text

Effects of Substrate Temperature on the Properties of Silicon Oxide Films by PECVD

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.198-199.28 ◽

2012 ◽

Vol 198-199 ◽

pp. 28-31

Author(s):

Chun Ya Li ◽

Xi Feng Li ◽

Long Long Chen ◽

Ji Feng Shi ◽

Jian Hua Zhang

Keyword(s):

Thin Film ◽

Thin Films ◽

Electrical Properties ◽

Photoelectron Spectroscopy ◽

Deposition Temperature ◽

Silicon Oxide ◽

Chemical Vapor ◽

Growth Conditions ◽

X Ray ◽

Glass Substrates

Under different growth conditions, silicon Oxide (SiOx) thin films were deposited successfully on Si (100) substrates and glass substrates by plasma enhanced chemical vapor deposition (PECVD). The thickness, refractive index and growth rate of the thin films were tested by ellipsometer. The effects of deposition temperature on the structure and properties of SiOx films were studied using X ray diffraction (XRD), X ray photoelectron spectroscopy (XPS) and UV-Visible spectroscopy. The results show that the SiOx films were amorphous at different deposition temperature. The peaks of Si2p and O1s shifted to higher binding energy with temperature increasing. The SiOx films had high transmissivity at the range of 400-900nm. By analyzing the observation and data, the influence of deposition parameters on the electrical properties and interface characteristics of SiOx thin film prepared by PECVD is systematically discussed. At last, SiOx thin film with excellent electrical properties and good interface characteristic is prepared under the relatively optimum parameters.

Download Full-text

Green Synthesis of Luminescent Gold-Zinc Oxide Nanocomposites: Cell Imaging and Visible Light–Induced Dye Degradation

Frontiers in Chemistry ◽

10.3389/fchem.2021.639090 ◽

2021 ◽

Vol 9 ◽

Author(s):

Kanika Bharti ◽

Shahbaz Ahmad Lone ◽

Ankita Singh ◽

Sandip Nathani ◽

Partha Roy ◽

...

Keyword(s):

Zinc Oxide ◽

Visible Light ◽

Green Synthesis ◽

Photoelectron Spectroscopy ◽

Sodium Citrate ◽

Dye Degradation ◽

X Ray ◽

Long Duration ◽

Solvent Free Conditions

Green synthesis of gold-zinc oxide (Au-ZnO) nanocomposite was successfully attempted under organic solvent–free conditions at room temperature. Prolonged stirring of the reaction mixture introduced crystallinity in the ZnO phase of Au-ZnO nanocomposites. Luminescence properties were observed in these crystalline Au-ZnO nanocomposites due to in situ embedding of gold nanoparticles (AuNP) of 5–6 nm diameter on the surface. This efficient strategy involved the reduction of Au(III) by Zn(0) powder in aqueous medium, where sodium citrate (NaCt) was the stabilizing agent. Reaction time and variation of reagent concentrations were investigated to control the Au:Zn ratio within the nanocomposites. The reaction with the least amount of NaCt for a long duration resulted in Au-ZnO/Zn(OH)2 nanocomposite. X-ray photoelectron spectroscopy (XPS) confirmed the formation of Zn(OH)2 and ZnO in the same nanocomposite. These nanocomposites were reconnoitered as bioimaging materials in human cells and applied for visible light–induced photodegradation of rhodamine-B dye.

Download Full-text

Photocatalysis over N-Doped TiO2 Driven by Visible Light for Pb(II) Removal from Aqueous Media

Catalysts ◽

10.3390/catal11080945 ◽

2021 ◽

Vol 11 (8) ◽

pp. 945

Author(s):

Endang Tri Wahyuni ◽

Titi Rahmaniati ◽

Aulia Rizky Hafidzah ◽

Suherman Suherman ◽

Adhitasari Suratman

Keyword(s):

Visible Light ◽

Photocatalytic Oxidation ◽

Irradiation Time ◽

Aqueous Media ◽

Visible Region ◽

Significant Activity ◽

Solution Ph ◽

Doped Tio2 ◽

Photo Oxidation ◽

N Doping

The photocatalysis process over N-doped TiO2 under visible light is examined for Pb(II) removal. The doping TiO2 with N element was conducted by simple hydrothermal technique and using urea as the N source. The doped photocatalysts were characterized by DRUVS, XRD, FTIR and SEM-EDX instruments. Photocatalysis of Pb(II) through a batch experiment was performed for evaluation of the doped TiO2 activity under visible light, with applying various fractions of N-doped, photocatalyst mass, irradiation time, and solution pH. The research results attributed that N doping has been successfully performed, which shifted TiO2 absorption into visible region, allowing it to be active under visible irradiation. The photocatalytic removal of Pb(II) proceeded through photo-oxidation to form PbO2. Doping N into TiO2 noticeably enhanced the photo-catalytic oxidation of Pb(II) under visible light irradiation. The highest photocatalytic oxidation of 15 mg/L Pb(II) in 25 mL of the solution could be reached by employing TiO2 doped with 10%w of N content 15 mg, 30 min of time and at pH 8. The doped-photocatalyst that was three times repeatedly used demonstrated significant activity. The most effective process of Pb(II) photo-oxidation under beneficial condition, producing less toxic and handleable PbO2 and good repeatable photocatalyst, suggest a feasible method for Pb(II) remediation on an industrial scale.

Download Full-text