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

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

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

Applied Science and Engineering Progress ◽

10.14416/j.asep.2021.10.007 ◽

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.

Download Full-text

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

Catalysts ◽

10.3390/catal11020235 ◽

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.

Download Full-text

Novel adsorption and photocatalytic oxidation for removal of gaseous toluene by V-doped TiO2/PU under visible light

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2015.07.048 ◽

2015 ◽

Vol 300 ◽

pp. 493-503 ◽

Cited By ~ 55

Author(s):

Thanh-Dong Pham ◽

Byeong-Kyu Lee

Keyword(s):

Visible Light ◽

Photocatalytic Oxidation ◽

Doped Tio2 ◽

Gaseous Toluene

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

Formation of hydroxyl radicals and kinetic study of 2-chlorophenol photocatalytic oxidation using C-doped TiO2, N-doped TiO2, and C,N Co-doped TiO2 under visible light

Environmental Science and Pollution Research ◽

10.1007/s11356-015-5570-8 ◽

2015 ◽

Vol 23 (4) ◽

pp. 3884-3896 ◽

Cited By ~ 31

Author(s):

Jirapat Ananpattarachai ◽

Supapan Seraphin ◽

Puangrat Kajitvichyanukul

Keyword(s):

Visible Light ◽

Kinetic Study ◽

Hydroxyl Radicals ◽

Photocatalytic Oxidation ◽

Doped Tio2 ◽

Co Doped

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

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

Material Science Research India ◽

10.13005/msri/150301 ◽

2018 ◽

Vol 15 (3) ◽

pp. 197-208 ◽

Cited By ~ 5

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.

Download Full-text

Photocatalytic Reduction of Methyl Orange Using Titania Photocatalyst Codoped with Nitrogen and Gadolinium under Visible Light Illumination

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.2127 ◽

2009 ◽

Vol 79-82 ◽

pp. 2127-2130 ◽

Cited By ~ 1

Author(s):

Song Tao Gu ◽

Xin Wang ◽

Qiang Liu ◽

Hao Quan Liu ◽

Gui Jun Jiang ◽

...

Keyword(s):

Photocatalytic Activity ◽

Methyl Orange ◽

Visible Light ◽

Synergistic Effects ◽

Sol Gel ◽

Visible Region ◽

Light Illumination ◽

Active Nitrogen ◽

Doped Tio2 ◽

Codoped Tio2

A visible-light-active nitrogen and gadolinium codoped TiO2 catalyst was synthesized by the sol-gel route. For comparison, Gd-doped sample, N-doped sample, and pure titania were prepared through the same method, without adding the corresponding dopants. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD) and Uv-vis spectra. The results showed that the codoped photocatalyst exhibited a smaller size than the undoped titania. The transformation from anatase to rutile was suppressed by doping with N and Gd atoms. Furthermore, the absorbance spectra of N, Gd-codoped TiO2 exhibited a significant red shift to the visible region. The photocatalytic activity of N, Gd-codoped TiO2 was evaluated by photodegradation of methyl orange under visible light irradiation. This codoped sample exhibited enhanced photocatalytic activity compared to N-doped TiO2, Gd-doped TiO2, and pure TiO2. The improvement of the photocatalytic activity was ascribed to the synergistic effects of the N and Gd co-doping.

Download Full-text