scholarly journals TiO2Nanocatalysts Supported on a Hybrid Carbon-Covered Alumina Support: Comparison between Visible Light and UV Light Degradation of Rhodamine B

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Mphilisi M. Mahlambi ◽  
Ajay K. Mishra ◽  
Shivani B. Mishra ◽  
Rui W. Krause ◽  
Bhekie B. Mamba ◽  
...  
Keyword(s):  
Visible Light ◽  
Rhodamine B ◽  
Uv Light ◽  
Reaction Rate Constant ◽  
Titania Nanoparticles ◽  
Impregnation Method ◽  
Alumina Support ◽  
Photodegradation Efficiency ◽  
Carbon Covered Alumina ◽  
Hybrid Carbon

Titania nanoparticles were successfully supported on carbon-covered alumina (CCA) supports via the impregnation method to form carbon-covered alumna titania (CCA/TiO2). The CCA supports were synthesised through an equilibrium adsorption of toluene 2,4-diisocyante where the N=C=O irreversibly adsorbs on the alumina and pyrolysis at 700°C affords CCA supports. These CCA/TiO2nanocatalysts were tested for their photocatalytic activity both under UV and visible light using Rhodamine B as a model pollutant. The reaction rate constant of the CCA/TiO2was found to be higher than that of unsupported titania and the reaction kinetics were found to follow an apparent first-order rate law. The CCA/TiO2nanocatalysts had a much larger surface area than the unsupported titania and they exhibited overall higher photodegradation efficiency under both UV and visible light than unsupported TiO2.

scholarly journals Photodegradation of Rhodamine B in Presence of CaO and NiO-CaO Catalysts

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Tobias Kornprobst ◽  
Johann Plank
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Rhodamine B ◽  
Uv Light ◽  
Mechanistic Study ◽  
Light Conditions ◽  
No Adsorption ◽  
Charged Surfaces ◽  
Positively Charged

A CaO catalyst was prepared by mild calcination (650°C) of facilely precipitated Ca(OH)2and compared to an NiO-CaO catalyst obtained from an Ni(OH)2/Ca(OH)2coprecipitate as a precursor. Both catalysts degraded rhodamine B (RB) effectively when exposed to ultraviolet light but exhibited slower degradation under visible light conditions. Under UV light, CaO was more effective than NiO-CaO, while in visible light, the opposite was observed. A mechanistic study revealed no influence of the specific surface area of the catalysts on RB degradation, no adsorption of RB on the positively charged surfaces of the catalysts, and only incomplete degradation of RB. Consequently, both materials represent nonconventional photocatalysts.

scholarly journals Synthesis of V2O5 Nanoflakes on PET Fiber as Visible-Light-Driven Photocatalysts for Degradation of RhB Dye

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yim-Leng Chan ◽  
Swee-Yong Pung ◽  
Srimala Sreekantan
Keyword(s):  
Visible Light ◽  
Uv Light ◽  
High Surface ◽  
Research Work ◽  
High Surface Area ◽  
Order Kinetic ◽  
Polymeric Fibers ◽  
Photodegradation Efficiency ◽  
Continuous Flow Condition ◽  
Visible Light Driven

The visible-light-driven semiconductor photocatalysts are the current research focus techniques used to decompose organic pollutants/compounds. The photodegradation efficiency of organic compounds by photocatalyst is expected to be better compared to UV-light-driven semiconductor photocatalysts technique since the major components of our solar energy are visible light (~44%). However, as most of the previous research work has been carried out using semiconductor photocatalysts in the form of powder, extra steps and costs are needed to remove this powder from the slurry to prevent secondary pollution. In this research work, we will explain our fabrication technique of V2O5 nanoflakes by growing radially on PET fibers. By utilizing the flexibility and high surface area of polymeric fibers as novel substrate for the growth of V2O5 nanoflakes, the Rhodamine B (RhB) could be degraded under visible light irradiation. The photodegradation of RhB solution by V2O5 nanoflakes followed the 1st order kinetic with a constant rate of 0.0065 min−1. The success of this research work indicates that V2O5 nanoflakes grown on PET fibre could be possibly used as organic waste water purifier under continuous flow condition. A photodegradation mechanism of V2O5 nanostructures to degrade RhB dye is proposed based on the energy diagram.

scholarly journals Hydrothermal Synthesis of MoS2/rGO Heterostructures for Photocatalytic Degradation of Rhodamine B under Visible Light

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Thi Thuy Trang Phan ◽  
Thi Thanh Huong Nguyen ◽  
Ha Tran Huu ◽  
Thanh Tam Truong ◽  
Le Tuan Nguyen ◽  
...  
Keyword(s):  
Visible Light ◽  
Rhodamine B ◽  
Life Time ◽  
Absorption Capacity ◽  
Mass Ratio ◽  
Hydrothermal Temperature ◽  
Synthesis Conditions ◽  
Photodegradation Efficiency ◽  
Reduced Graphene ◽  
Structure Morphology

MoS2/rGO composites were synthesized by hydrothermal method from the precursors of MoS2 and reduced graphene oxide (rGO) prepared in the former steps. The influence of the synthesis conditions including hydrothermal temperature and mass ratio of MoS2 to rGO on the structure, morphology, and optical absorption capacity of the MoS2/rGO composites was systematically investigated using physicochemical characterizations. The photocatalytic performance of as-prepared samples was investigated on the degradation of Rhodamine B under visible light, in which, the composites obtained at hydrothermal temperature of 180°C and MoS2/rGO mass ratio of 4/1 exhibited the highest photodegradation efficiency of approx. 80% after 4 hours of reaction. This enhancement in photocatalytic behaviour of composites could be assigned to the positive effect of rGO in life time expansion of photoinduced electrons—holes.

MICROWAVE-ASSISTED HYDROTHERMAL SYNTHESIS OF NITROGEN-DOPED TITANIA NANOPARTICLES

2008 ◽  
Vol 01 (03) ◽  
pp. 173-176 ◽  
Author(s):  
SHU YIN ◽  
BIN LIU ◽  
TSUGIO SATO
Keyword(s):  
Visible Light ◽  
Uv Light ◽  
Hydrothermal Process ◽  
Nitrogen Monoxide ◽  
High Specific Surface Area ◽  
Titania Nanoparticles ◽  
Photocatalytic Ability ◽  
Nitrogen Doped ◽  
Microwave Assisted ◽  
Doped Titania

Nitrogen-doped titania ( TiO 2-x N y) nanoparticles with excellent visible-light-reactive photocatalytic activity were successfully prepared by a microwave-assisted hydrothermal process. The obtained TiO 2-x N y powders showed high specific surface area, fine particle size and excellent photocatalytic ability for the oxidative destruction of nitrogen monoxide under irradiation of both visible-light (λ > 510 nm) and UV light (λ > 290 nm).

Synthesis and characterization of BN/Bi2WO6 composite photocatalysts with enhanced visible-light photocatalytic activity

RSC Advances ◽  
2015 ◽  
Vol 5 (108) ◽  
pp. 88832-88840 ◽  
Author(s):  
Weibin Li ◽  
Qi Wang ◽  
Liying Huang ◽  
Yeping Li ◽  
Yuanguo Xu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Rhodamine B ◽  
Synthesis And Characterization ◽  
Impregnation Method ◽  
Visible Light Photocatalytic Activity ◽  
Composite Photocatalysts ◽  
Visible Light Photocatalytic

Bi2WO6 modified with few-layer BN was synthesized by an impregnation method. The as-prepared BN/Bi2WO6 photocatalysts exhibited a higher photocatalytic activity for the degradation of Rhodamine B (RhB) than the pure Bi2WO6.

Photocatalytic Degradation of Carbaryl over Novel MWNT-TiO2 Nanocomposite under Visible Light Irradiation

2011 ◽  
Vol 233-235 ◽  
pp. 476-480
Author(s):  
Ke Dai ◽  
Hai Bo Chen ◽  
Xu Li ◽  
Hao Chen ◽  
Qiao Yun Huang
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Ring Opening ◽  
Uv Light ◽  
Light Irradiation ◽  
Photodegradation Efficiency ◽  
Uv Light Irradiation ◽  
Ring Opening Reaction ◽  
Visible Light Driven ◽  
Direct Growth

The MWNT-TiO2nanocomposite was synthesized via direct growth of TiO2nanoparticles on the surface of the functionalized MWNTs by the hydrothermal treatment and utilized as the photocatalyst in the carbaryl degradation under both visible light and UV light irradiation. Visible-light-driven activity and enhanced UV-light-driven activity are both achieved as the composite MWNTs with TiO2can efficiently enhance the light absorption and charge separation and then photocatalytic activity. The photodegradation efficiency of carbaryl was examined by HPLC and IC techniques, which demonstrates that carbaryl can be readily degraded under visible light irradiation. Based on the obtained experimental results, assisted with the computer simulation of carbaryl molecule on PM3 level, it is presumed that the degradation of carbaryl starts with the break of N21-C23 and C19-N21 bonds and ends in the generation of naphthalen-1-ol before the ring-opening reaction.

Research on Photochromic Compounds with Synthesis and Photochromism of 1-(2-methyl-3-benzofuryl)-2-{2-methyl-5-[4-formyloxyethyl (Rhodamine-B)] phenyl-3-thienyl} Perfluoroyclopentene

2014 ◽  
Vol 1003 ◽  
pp. 55-58
Author(s):  
Dan Dan Xue ◽  
Guan Ming Liao ◽  
Chun Hong Zheng ◽  
Shou Zhi Pu
Keyword(s):  
Visible Light ◽  
Rhodamine B ◽  
Uv Light ◽  
Amorphous Film ◽  
Order Reaction ◽  
First Order Reaction ◽  
Pmma Film ◽  
Photochromic Properties ◽  
Photochromic Compounds ◽  
First Order

A new photochromic diarylethene compound bearing a rhodamine B unit, 1-(2-methyl-3-benzofuryl)-2-{2-methyl-5-[4-formyloxyethyl (rhodamine-B)] phenyl-3-thienyl} perfluorocyclopentene (1o) was synthesized, and its photochromic properties such as photochromism in solution as well as in a polymethylmethacrylate (PMMA) amorphous film were investigated specfically. 1o exhibits good photochromism upon alternating irradiation with UV light and visible light (> 510 nm) in hexane and a PMMA film. The kinetic experiments showed that the cyclization and cycloreversion processes were zeroth and first order reaction, respectively.

Effect of Metal Ions (Ag, Co, Ni, and Pd) on the Visible Light Degradation of Rhodamine B by Carbon-Covered Alumina-Supported TiO2 in Aqueous Solutions

2013 ◽  
Vol 52 (5) ◽  
pp. 1783-1794 ◽  
Author(s):  
Mphilisi M. Mahlambi ◽  
Ajay K. Mishra ◽  
Shivani B. Mishra ◽  
Rui W. Krause ◽  
Bhekie B. Mamba ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Visible Light ◽  
Metal Ions ◽  
Rhodamine B ◽  
Supported Tio2 ◽  
Visible Light Degradation ◽  
Carbon Covered Alumina

scholarly journals Photocatalytic activity under visible light irradiation of cement based materials containing TiO2-xNy nanoparticles

2019 ◽  
pp. 87-96
Author(s):  
Ludovic I. Dorkis ◽  
Juan David Cohen ◽  
Jorge I. Tobón
Keyword(s):  
Visible Light ◽  
Rhodamine B ◽  
Uv Light ◽  
Light Irradiation ◽  
Efficiency Coefficient ◽  
Photocatalytic Efficiency ◽  
X Ray Diffraction ◽  
Cement Pastes ◽  
Uv Light Irradiation ◽  
Munk Function

Self-cleaning activity of Portland cement pastes blended with nanoparticles of titanium oxynitride (TiO2−xNy) was studied. Samples with various amounts of TiO2−xNy (1% and 3%) were evaluated under irradiation of UV and visible light, and with two curing ages (65 hour and 28 days). Rhodamine B was the pigment used and its loss of color on the cement pastes was carried out using a Spectrometer UV/Vis measuring the coordinates CIE (Commission Internationale de l’Eclairage) L∗, a∗, b∗. Discoloration of Rhodamine B on the surface of the samples was established as the photocatalytic efficiency coefficient (ε). In addition, samples with TiO2 nanoparticles (1% and 3%) were studied under the same conditions and their performances were compared with TiO2-xNy. The presence of nitrogen in the tetragonal structure of TiO2 was evidenced by X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectrophotometry and Carbon, Hydrogen and Nitrogen (CHN) analysis. The band gap for TiO2 and TiO2-xNy was determined by the transformed Kubelka-Munk function ( [F (R∞) hv]1/2). The results have shown a similar behavior for both additions under UV light irradiation, with 3% being the addition with the highest photocatalytic efficiency obtained in the early ages of curing time.  TiO2−xNy showed activity under irradiation with visible light, unlike TiO2, which could only be activated under UV light.  At the late curing ages, the samples with 3% of TiO2-xNy showed the highest efficiency under irradiation of UV and visible light.

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