scholarly journals Fast and complete degradation of Congo red under visible light with Er3+ and Nd3+ ions doped TiO2 nanocomposites

2011 ◽  
Vol 2 (1) ◽  
pp. 2 ◽  
Author(s):  
Himanshu Narayan ◽  
Hailemichael Alemu ◽  
Daniel N. Alotsi ◽  
Lebohang Macheli ◽  
Madhavi Thakurdesai ◽  
...  
Keyword(s):  
Particle Size ◽  
Visible Light ◽  
Congo Red ◽  
Energy Levels ◽  
Intermediate Energy ◽  
Doped Tio2 ◽  
Complete Destruction ◽  
Efficient Suppression ◽  
Visible Irradiation ◽  
Co Precipitation

We report fast and complete destruction of the dye Congo red (CR) under visible light in the presence of Nd3+ and Er3+ doped TiO2 nanocomposites (NCs). TiO2 NCs with general composition TiO2[R2O3]x, {x=0.1, 0.2; R≡ Nd, Er} and particle size 12-16 nm were synthesized through co-precipitation/hydrolysis (CPH). A set of similar composites was also prepared through solid state reaction (SSR) route, which produced 31- 47 nm particles. After characterization, visible light photocatalytic activity of all the samples was recorded for the degradation of CR. NCs with molar concentration x=0.2 of both doping types produced close to 100% degradation in 180 min. The apparent rate constant (kobs) was found to be 2.91×10–2 min–1 and 2.36×10–2 min–1, for these Nd3+ and Er3+ doped NCs, respectively. The other NCs with x=0.1, also showed significant degradation of CR, but the samples prepared through SSR performed worse. The excellent degradation obtained with the NCs may be attributed to their small particle size. Moreover, the doping of Nd3+ and Er3+ ions further supported the photocatalysis through formation of intermediate energy levels within the band gap of TiO2. These new levels not only acted as electron traps for efficient suppression of the undesired e–/h+ recombination, but also facilitated to a certain extent the absorption of visible irradiation.

Effect of Transition Metal Oxide Doping (Cr, Co, V) in the Photocatalytic Activity of TiO2 for Congo Red Degradation under Visible Light

2014 ◽  
Vol 69 (5) ◽  
Author(s):  
P. W. Koh ◽  
L. Yuliati ◽  
S. L. Lee
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Congo Red ◽  
Sol Gel ◽  
Rutile Phase ◽  
Band Gap Energy ◽  
Electron Recombination ◽  
Doped Tio2 ◽  
Light Region ◽  
Electron Scavenger

Comparative study of Cr, Co or V-doped TiO2 was carried out. The photocatalysts were synthesized via sol-gel method. The results indicated that the dopants of Cr, Co, and V induced anatase to rutile phase transition of TiO2 at different dopant amounts of 1, 4, 2 mol%, respectively. Besides that, the existence of dopant extended the absorption wavelength of TiO2 to visible light region, thus making it a visible-driven photocatalyst. The doped transition metal exhibited different oxidation states on the TiO2 surface. The prepared photocatalysts were tested over photodegradation of Congo Red. Amongst all, Cr-doped TiO2 (3 mol%) was the best photocatalyst attributed to the presence of 45% rutile phase, reduced band gap energy of 2.30 eV and formation of Cr6+, which acted as an electron scavenger to delay the hole-electron recombination. 

scholarly journals Role of particle size in visible light photocatalysis of Congo Red using TiO2·[ZnFe2O4] x nanocomposites

2009 ◽  
Vol 32 (5) ◽  
pp. 499-506 ◽  
Author(s):  
Himanshu Narayan ◽  
Hailemichael Alemu ◽  
Lebohang Macheli ◽  
Mantoa Sekota ◽  
Madhavi Thakurdesai ◽  
...  
Keyword(s):  
Particle Size ◽  
Visible Light ◽  
Congo Red ◽  
Visible Light Photocatalysis

Doping level effect on visible-light irradiation W-doped TiO2–anatase photocatalysts for Congo red photodegradation

2014 ◽  
Vol 17 (7-8) ◽  
pp. 818-823 ◽  
Author(s):  
Asma Mayoufi ◽  
Mohamed Faouzi Nsib ◽  
Ammar Houas
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Congo Red ◽  
Doping Level ◽  
Light Irradiation ◽  
Doped Tio2 ◽  
Tio2 Anatase ◽  
Level Effect

scholarly journals Visible Light Photocatalysis with Rare Earth Ion-Doped Nanocomposites

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Himanshu Narayan ◽  
Hailemichael Alemu ◽  
Lijeloang Setofolo ◽  
Lebohang Macheli
Keyword(s):  
Particle Size ◽  
Rare Earth ◽  
Visible Light ◽  
Apparent Rate Constant ◽  
Rare Earth Ions ◽  
Rare Earth Ion ◽  
Effective Suppression ◽  
Co Precipitation ◽  
Average Size ◽  
Visible Light Photocatalytic

Rare earth (R) ion-doped TiO2 nanocomposites (NCs) with general composition (R: Y, Yb, Gd; , 0.2) were synthesized through co-precipitation/hydrolysis (CPH). NC particles with average size of approximately a few tens of nm were obtained. Similar compositions of polycrystalline (PC) samples with larger particle size were also prepared employing solid state reaction (SSR) method. Visible light photocatalytic activity of all samples was investigated for degradation of Congo red (CR) dye. Both in terms of apparent rate constant () and percent degradation after 180 min (), all NCs produced significantly enhanced degradation as compared to pure TiO2 and PC samples. Best degradation of 95% ( value) resulted with composition of Y3+ doped NC with  min−1. This was followed by of 85 and 80%, produced with Yb3+ and Gd3+ doped, NCs, at around and  min−1, respectively. The observations clearly suggest that enhanced photocatalytic degradation of CR is directly related to smaller particle size of the catalysts. Moreover, the presence of rare earth ions in the composites facilitates further improvement of degradation efficiency through effective suppression of recombination.

scholarly journals Synthesis of N-Doped TiO2 for Efficient Photocatalytic Degradation of Atmospheric NOx

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 109
Author(s):  
Tamal Khan ◽  
Gazi Bari ◽  
Hui-Ju Kang ◽  
Tae-Gyu Lee ◽  
Jae-Woo Park ◽  
...  
Keyword(s):  
Visible Light ◽  
Nitrogen Doping ◽  
No Oxidation ◽  
Doped Tio2 ◽  
Tio2 Lattice ◽  
Light Region ◽  
Wide Range ◽  
Photocatalytic Activities ◽  
Co Precipitation ◽  
High Degree

Titanium oxide (TiO2) is a potential photocatalyst for removing toxic NOx from the atmosphere. Its practical application is, however, significantly limited by its low absorption into visible light and a high degree of charge recombination. The overall photocatalytic activity of TiO2 remains too low since it can utilize only about 4–5% of solar energy. Nitrogen doping into the TiO2 lattice takes advantage of utilizing a wide range of solar radiation by increasing the absorption capability towards the visible light region. In this work, N-doped TiO2, referred to as TC, was synthesized by a simple co-precipitation of tri-thiocyanuric acid (TCA) with P25 followed by heat treatment at 550 degrees C. The resulting nitrogen doping increased the visible-light absorption and enhanced the separation/transfer of photo-excited charge carriers by capturing holes by reduced titanium ions. As a result, TC samples exhibited excellent photocatalytic activities of 59% and 51% in NO oxidation under UV and visible light irradiation, in which the optimum mass ratio of TCA to P25 was found to be 10.

Correlating the visible light photoactivity of N-doped TiO2 with brookite particle size and bridged-nitro surface species

2012 ◽  
Vol 17 ◽  
pp. 1-7 ◽  
Author(s):  
Zs. Pap ◽  
L. Baia ◽  
K. Mogyorósi ◽  
A. Dombi ◽  
A. Oszkó ◽  
...  
Keyword(s):  
Particle Size ◽  
Visible Light ◽  
Surface Species ◽  
Doped Tio2

Visible Light Active Ce-doped TiO2 Nanoparticles for Photocatalytic Degradation of Methylene Blue

2016 ◽  
Vol 13 (1) ◽  
pp. 110-116 ◽  
Author(s):  
Rani P. Barkul ◽  
Farah-Naaz A. Shaikh ◽  
Sagar D. Delekar ◽  
Meghshyam K. Patil
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Tio2 Nanoparticles ◽  
Doped Tio2 ◽  
Visible Light Active

Visible Light Photocatalytic Decolourization of Methyl Orange Using N-Doped TiO2 Nanoparticles

2015 ◽  
Vol 18 (3) ◽  
pp. 1-9 ◽  
Author(s):  
Hussein M. Hadi ◽  
◽  
Hilal S. Wahab ◽  
Keyword(s):  
Methyl Orange ◽  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Doped Tio2 ◽  
Visible Light Photocatalytic

A New Route for the Synthesis of Visible-Light Driven Ag,V Co-Doped TiO2 for Degradation of Organic Pollutant

2020 ◽  
Vol 94 (13) ◽  
pp. 2715-2722
Author(s):  
M. K. Ntobeng ◽  
R. Akbarzadeh
Keyword(s):  
Visible Light ◽  
Organic Pollutant ◽  
Doped Tio2 ◽  
Visible Light Driven ◽  
Co Doped
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