Enhanced Photocatalytic Activity of N/Li2MoO4 Co-doped TiO2 Nanoparticles under Visible Light

2021 ◽  
Author(s):  
Jutarat Kwakkaew ◽  
Matthana Khangkhamano ◽  
Rungrote Kokoo ◽  
Weerachai Sangchay
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Visible Region ◽  
Strong Light ◽  
Doped Tio2 ◽  
Vis Spectroscopy ◽  
Wide Range

TiO2-based nanomaterials have been extensively synthesized and used in a wide range of photocatalytic applications. The photocatalytic oxidation process, however, is only activated by irradiation with ultraviolet (UV) light which limits its indoor applications. Herein, to improve such limitations, N/Li2MoO4-doped TiO2 nanoparticles were prepared via sol-gel method. Li2MoO4 concentration was varied. The catalysts were characterized by XRD, XPS, FE-SEM, and UV-Vis spectroscopy. As-synthesized N/Li2MoO4-doped TiO2 catalysts exhibited their crystal sizes of as fine as 20 nm in diameter whereas that of the pure TiO2 was about 35 nm. The absorption ranges of the N/ Li2MoO4-doped catalysts were relocated from UV region toward visible light region. The catalyst with 1 mol% Li2MoO4 offered the highest degradation rate of methylene blue (MB) solution upon visible light irradiation. Its fine crystal size, narrow band gap energy (2.82 eV), high defect concentration, and strong light absorption in visible region are responsible for the enhanced photocatalytic activity of the 1 mol% Li2MoO4.

scholarly journals MoS2/Cu/TiO2 nanoparticles: synthesis, characterization and effect on photocatalytic decomposition of methylene blue in water under visible light

2018 ◽  
Vol 2017 (1) ◽  
pp. 184-193 ◽  
Author(s):  
Desireé M. de los Santos ◽  
Sara Chahid ◽  
Rodrigo Alcántara ◽  
Javier Navas ◽  
Teresa Aguilar ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Visible Region ◽  
Pure Tio2 ◽  
Photocatalytic Decomposition ◽  
Tio2 Sample ◽  
X Ray ◽  
Vis Spectroscopy

Abstract Photodegradation processes are of great interest in a range of applications, one of which is the photodecomposition of pollutants. For this reason, analysing nanoparticles that improve the efficiency of these processes under solar radiation are very necessary. Thus, in this study, TiO2 was doped with Mo and Cu using low-temperature hydrolysis as the method of synthesis. Pure TiO2 and x%MoS2/Cu/TiO2 nanoparticles were prepared, where x is the theoretical quantity of MoS2 added (0.0%, 1.0%, 5.5%, 10.0%), setting the nominal quantity of Cu at 0.5 wt.%. The samples obtained were characterized by X-ray diffraction, Raman spectroscopy, X-ray electron spectroscopy and UV-Vis spectroscopy in diffuse reflectance mode. The results suggest that the TiO2 structure was doped with the Mo6+ and Cu2+ ions in the position of the Ti4+. The x%MoS2/Cu/TiO2 samples presented lower band gap energy values and greater optical absorption in the visible region than the pure TiO2 sample. Lastly, the photocatalytic activity of the samples was assessed by means of the photodegradation of methylene blue under visible light. The results show that when the quantity of Mo in the co-doped samples increased (x%MoS2/Cu/TiO2) there were significant increases of up to 93% in the photocatalytic activity.

scholarly journals Green Synthesis of N/Zr Co-Doped TiO2 for Photocatalytic Degradation of p-Nitrophenol in Wastewater

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 235
Author(s):  
Hayette Benkhennouche-Bouchene ◽  
Julien G. Mahy ◽  
Cédric Wolfs ◽  
Bénédicte Vertruyen ◽  
Dirk Poelman ◽  
...  
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Visible Region ◽  
Chemical Properties ◽  
Pure Tio2 ◽  
Molar Ratio ◽  
Xps Spectra ◽  
Doped Tio2 ◽  
Co Doped

TiO2 prepared by a green aqueous sol–gel peptization process is co-doped with nitrogen and zirconium to improve and extend its photoactivity to the visible region. Two nitrogen precursors are used: urea and triethylamine; zirconium (IV) tert-butoxide is added as a source of zirconia. The N/Ti molar ratio is fixed regardless of the chosen nitrogen precursor while the quantity of zirconia is set to 0.7, 1.4, 2, or 2.8 mol%. The performance and physico-chemical properties of these materials are compared with the commercial Evonik P25 photocatalyst. For all doped and co-doped samples, TiO2 nanoparticles of 4 to 8 nm of size are formed of anatase-brookite phases, with a specific surface area between 125 and 280 m2 g−1 vs. 50 m2 g−1 for the commercial P25 photocatalyst. X-ray photoelectron (XPS) measurements show that nitrogen is incorporated into the TiO2 materials through Ti-O-N bonds allowing light absorption in the visible region. The XPS spectra of the Zr-(co)doped powders show the presence of TiO2-ZrO2 mixed oxide materials. Under visible light, the best co-doped sample gives a degradation of p-nitrophenol (PNP) equal to 70% instead of 25% with pure TiO2 and 10% with P25 under the same conditions. Similarly, the photocatalytic activity improved under UV/visible reaching 95% with the best sample compared to 50% with pure TiO2. This study suggests that N/Zr co-doped TiO2 nanoparticles can be produced in a safe and energy-efficient way while being markedly more active than state-of-the-art photocatalytic materials under visible light.

scholarly journals Visible Light-Driven high Photocatalytic Activity of Cu-Doped TiO2 Nanoparticles Synthesized by Hydrothermal Method

2018 ◽  
Vol 15 (3) ◽  
pp. 197-208 ◽  
Author(s):  
Ravi Kamble ◽  
Smita Mahajan ◽  
Vijaya Puri ◽  
Harish Shinde ◽  
Kalayanrao Garadkar
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Hydrothermal Method ◽  
Anatase Phase ◽  
Visible Region ◽  
Oxygen Demand ◽  
High Photocatalytic Activity ◽  
Tio2 Nps ◽  
Doped Tio2 ◽  
Tio2 Lattice

TiO2 and Cu-doped TiO2 nanoparticles (NPs) with totally extraordinary substance of Cu by exploitation hydrothermal method. The part immaculateness, morphology, molecule estimate, optical properties, and elemental composition of as-incorporated Cu-doped TiO2 NPs were investigated by numerous systematic methods. The XRD designs unveiled Cu-doped TiO2 NPs inside the part unadulterated anatase phase. The plane of (101) XRD and XPS results show the lucky doping of Cu2+ inside the TiO2 lattice. The optical edges of Cu-doped TiO2 demonstrated a transparent light absorption in visible region that assumes an essential part inside the photocatalytic action underneath characteristic daylight. Certain Cu2+ content shows least PL intensity that backings the decrease in recombination rate of charge species. In addition, to get a handle on photocatalytic action, we have tried Cu-doped TiO2 for the degradation of Malachite Green (MG) under visible light. A large portion of 85% degradation was found for Cu-doped TiO2 (1.71 wt.%) underneath daylight minimum of 180 min, severally, that is past that of TiO2 (53%). Also, the degradation of the MG was affirmed by measurement of the chemical oxygen demand of the photodegraded solution. These outcomes demonstrates that the Cu-doped TiO2 NPs are extremely productive for the photodegration of the MG.

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

Catalysts ◽  
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.

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