Microwave Assisted Solvothermal Synthesis and Visible Light Photocatalytic Properties of Nb and N Co-Doped SrTiO3 Nanoparticles

2010 ◽  
Vol 63 ◽  
pp. 52-57 ◽  
Author(s):  
Uyi Sulaeman ◽  
Shu Yin ◽  
Tsugio Sato

Niobium and nitrogen co-doped SrTiO3 possessing excellent visible light responsive photocatalytic activity was successfully synthesized by microwave-assisted solvothermal reaction using SrCl2.6H2O, Ti(OC3H7)4, NbCl5 and hexamethylenetetramine in KOH aqueous solution. The photocatalytic activity was determined by DeNOx ability using LED lamps with the wavelengths of 627 nm (red), 530 nm (green), 445 nm (blue) and 390 nm (UV). The photocatalytic activity of SrTiO3 for DeNOx ability in visible light region could be improved by co-doping Nb5+ and N3-. The excellent visible light photocatalytic activity of this substance may be due to the generation of a new band gap that enables to absorb visible light and decrease in the lattice defects which acts as a recombination center of photoinduced electrons and holes.

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Uyi Sulaeman ◽  
Shu Yin ◽  
Tsugio Sato

Ta and N co-doped SrTiO3was synthesized by microwave-assisted solvothermal reaction using SrCl2⋅6H2O, Ti(OC3H7)4, TaCl5, and HMT (hexamethylenetetramine) in KOH and oleic acid mixed solutions. The products were characterized by XRD, TG-DTA, BET surface area measurement, TEM, EDX, DRS, PL-Spectra, and XPS. The nanoparticles of perovskite-type SrTi1-xTaxO3-yNy(x=0−0.1) were successfully synthesized. The photocatalytic activity of SrTiO3for DeNOxability in the visible light region could be improved by the codoping of Ta5+and N3-. The excellent visible light photocatalytic activity of this substance may be due to the generation of a new band gap by doping nitrogen that enables the absorption of visible light as well as a decrease in the incidence of the lattice defects, which acts as a recombination center of photo-induced electrons and holes by codoping with Ta5+.


2011 ◽  
Vol 239-242 ◽  
pp. 1923-1928
Author(s):  
Qian Lin Chen ◽  
Yuan Wang ◽  
Chun Yan Zhong ◽  
Yu Guo

La3+/halogen (F-, Cl-and Br-) co-doped TiO2was synthesized by alkoxide hydrolysis method. The prepared La3+/halogen TiO2photocatalysts with anatase phases and rutile phases were characterized with XRD, EDS, TEM and surface area analytic technology. Methyl orange was used as model pollutants to evaluate its visible light photocatalytic activity. The results showed that the co-doping of La3+and halogen ions improved the surface area of TiO2. Compared with 450°C and 650°C, La3+/Cl-and La3+/Br-co-doped TiO2calcined at 550°C exhibited much higher photocatalytic activity. The optimal doping ratio of La3+/F-, La3+/Cl-and La3+/Br-was 0.4, 0.6, and 0.5 ((wt%)/(wt%)), respectively. Moreover, the degradation ratio of methyl orange on La3+/halogen co-doped TiO2with the optimal ratio were all higher than the maximum degradation ratio on La3+, F-, Cl-and Br-doped TiO2prepared by the same method.


2020 ◽  
Vol 12 (3) ◽  
pp. 449-453 ◽  
Author(s):  
Bo Wang ◽  
Ruiling Zhang ◽  
Jin Xu ◽  
Songyan Qin ◽  
Jiajun Zheng ◽  
...  

N doped TiO2 nano-crystalline was prepared through hydrolysis-precipitation process in the presence of ammonia water. The resulting materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). It was found that N was incorporated into the lattice of TiO2 through substituting lattice oxygen atoms and coexisted in the forms of substitutional N (O–Ti–N) and interstitial N (Ti–O–N). Further, doping with N could greatly improve the phase transformation of TiO2 from rutile to anatase and light absorption in visible light region. The high visible light photocatalytic activity for the degradation of RhB of N doped TiO2 was mainly attributed to the small crystallite size, mixed phase composition, intense light absorption in visible light region, narrow band gap energy and surface hydroxyl groups.


2016 ◽  
Vol 16 (4) ◽  
pp. 3570-3576 ◽  
Author(s):  
Yulong Hu ◽  
Fu Dong ◽  
Hongfang Liu ◽  
Xingpeng Guo

Pd and Pt modified N-doped titania nanoparticle powders were prepared by a facile sol–gel method. Nitrogen doping and metal modification were carried out simultaneously during the preparation process. The as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and X-ray photoelectron spectroscopy (XPS). The visible light photocatalytic activities of the asprepared samples were evaluated by analyzing their effect on the photocatalytic decomposition of methyl orange (MO). The chemical state of the metal is the key factor determining the performance of metal modified N-doped titania. The Pd used to modify the N-doped titania (Pd-NT) in our study was of the PdOx(x≤2) species, which increased the absorbance in the visible light region, decreased the recombination of photo-generated electron–hole pairs, and resulted in a significant enhancement in the visible light photocatalytic activity. The Pt species used to modify the N-doped titania (Pt-NT) was mainly in the metallic state, which resulted in a decrease in the absorbance in the visible light region, and an increase in the recombination of photo-generated electron–hole pairs. Pt modification led to a deterioration in the visible light photocatalytic activity of the material.


Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 457 ◽  
Author(s):  
Huoli Zhang ◽  
Changxin Zhu ◽  
Jianliang Cao ◽  
Qingjie Tang ◽  
Man Li ◽  
...  

In this study, α-Fe2O3@g-C3N4 photocatalyst was synthesized using an ultrasonic assisted self-assembly preparation method. The α-Fe2O3@g-C3N4 photocatalyst had a stronger optical absorption in the visible light region than pure graphitic carbon nitride (g-C3N4). The Z-Scheme heterojunction between α-Fe2O3 and g-C3N4 significantly inhibited the recombination of electrons and holes. The photocatalytic performances of α-Fe2O3@g-C3N4 photocatalyst were excellent in degradation of Rhodamine B (RhB) under visible light irradiation. The results indicated that 5 wt.% α-Fe2O3/g-C3N4 had the optimal photocatalytic activity because two-dimension (2D) α-Fe2O3 nanosheets can be well-dispersed on the surface of g-C3N4 layers by ultrasonic assisted treatment. A possible photocatalytic mechanism is also discussed.


2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Uyi Sulaeman ◽  
Shu Yin ◽  
Tsugio Sato

Perovskite-type nitrogen-doped SrTiO3nanoparticles of 50–80 nm in diameter were successfully synthesized by the solvothermal of Ti(OC3H7)4, SrCl2⋅6H2O, and hexamethylenetetramine in KOH aqueous solution. Nitrogen-doped SrTiO3showed excellent photocatalytic activity under both UV and visible light irradiation, that is, the photocatalytic activity of N-doped SrTiO3for DeNOxreaction was greater than that of SrTiO3and commercial TiO2(Degussa P25) in both visible light region (>510 nm) and UV light region (>290 nm). The excellent visible light photocatalytic activity of this substance was caused by generating a new band gap that absorbs visible light.


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