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 Visible-Light-Driven SO42-/TiO2 Photocatalyst Synthesized from Binh Dinh (Vietnam) Ilmenite Ore for Rhodamine B Degradation

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Tan Lam Nguyen ◽  
Viet Dinh Quoc ◽  
Thi Lan Nguyen ◽  
Thi Thanh Thuy Le ◽  
Thanh Khan Dinh ◽  
...  
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Photocatalytic Degradation ◽  
Surface Area ◽  
Rhodamine B ◽  
Low Cost ◽  
Tio2 Photocatalyst ◽  
Tio2 Sample ◽  
Sunlight Irradiation ◽  
Visible Light Driven

A low-cost and simplistic approach for the synthesis of nanosized SO42-/TiO2 photocatalyst was successfully performed using Binh Dinh ilmenite ore and H2SO4 as titanium and sulfur sources, respectively. The experimental results indicate that the obtained material exists in the form of particles with a size of about 22 nm and has a specific surface area of about 49 m2 g-1. Compared with the TiO2 sample, the SO42-/TiO2 sample shows much higher photocatalytic degradation of rhodamine B (RhB) under the sunlight irradiation. In more details, the nanosized SO42-/TiO2 sample obtained is capable of completely decomposing RhB after 9 hours of irradiation by a 60 W LED lamp with a corresponding intensity of 9,500 Lux. However, when the SO42-/TiO2 is irradiated by the sunlight with the intensity of 65,000 Lux, it only takes 2 hours to completely decompose rhodamine B (RhB), facilitating the use of SO42-/TiO2 as a potential photocatalyst for the RhB photodegradation.

scholarly journals SYNTHESIS AND CHARACTERIZATION OF PHOTOCATALYS Fe2O3 PILLARED MONTMORILLONITE DOPED TiO2 AND ITS APPLICATION FOR RHODAMINE B PHODODEGRADATION USING VISIBLE LIGHT IRRADIATION

Jurnal Kimia ◽  
2020 ◽  
pp. 82
Author(s):  
D. A. D. N. Dewi ◽  
I N. Simpen ◽  
I W. Suarsa
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rhodamine B ◽  
High Specific Surface Area ◽  
Montmorillonite Clay ◽  
Pillared Montmorillonite ◽  
Bet Method ◽  
Acid And Base

A montmorillonite clay modified with semiconductor metal can act as a photocatalyst material. Montmorillonite clays were chosen because of their natural characteristics which are easily to be modified and have high specific surface area. This research aims to modify montmorillonite clay into photocatalyst material. The montmorillonite clay was intercalated using Fe2O3 to produce Fe2O3-pillared montmorillonite clay, then doped with TiO2 to form a photocatalyst material Fe2O3-PILC / TiO2. Modifications were intended to increase the specific surface area and number of active photocatalyst sites and thus increase the ability of photodegradation. The characterization carried out included characterizing the pillar formation using X-ray Diffraction (XRD), specific surface area by the BET method (Bruneau, Emmet, and Teller), a the number of surface acid-base sites by the titration method. Photocatalyst with the best character was Fe2O3-PILC / TiO2 1: 3 with specific surface area, number of acid and base sites respectively 45,947 m2/g, 20,1736 x 1023 sites/gram and 19,0044 x 1023 sites/gram. The result of photodegradation at optimum condition with visible light at pH 3 using 400 mg photocatalyst was 99.84%.   Keywords: photocatalyst, Fe2O3, montmorillonite clay, TiO2, rhodamine B

scholarly journals Photocatalytic H2 Evolution, CO2 Reduction, and NOx Oxidation by Highly Exfoliated g-C3N4

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1147
Author(s):  
Nadia Todorova ◽  
Ilias Papailias ◽  
Tatiana Giannakopoulou ◽  
Nikolaos Ioannidis ◽  
Nikos Boukos ◽  
...  
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Photocatalytic Performance ◽  
Uv Light ◽  
Co2 Reduction ◽  
H2 Production ◽  
Thermal Treatments ◽  
H2 Evolution ◽  
Photocatalytic H2 Evolution

g-C3N4, with specific surface area up to 513 m2/g, was prepared via three successive thermal treatments at 550 °C in air with gradual precursor mass decrease. The obtained bulk and exfoliated (1ex, 2ex and 3ex) g-C3N4 were characterized and tested as photocatalysts for H2 production, CO2 reduction and NOx oxidation. The exfoliated samples demonstrated graphene-like morphology with detached (2ex) and sponge-like framework (3ex) of layers. The surface area increased drastically from 20 m2/g (bulk) to 513 m2/g (3ex). The band gap (Eg) increased gradually from 2.70 to 3.04 eV. Superoxide radicals (·O2−) were mainly formed under UV and visible light. In comparison to the bulk, the exfoliated g-C3N4 demonstrated significant increase in H2 evolution (~6 times), CO2 reduction (~3 times) and NOx oxidation (~4 times) under UV light. Despite the Eg widening, the photocatalytic performance of the exfoliated g-C3N4 under visible light was improved too. The results were related to the large surface area and low e−-h+ recombination. The highly exfoliated g-C3N4 demonstrated selectivity towards H2 evolution reactions.

Preparation and Photocatalytic Properties of Nanosized La3+ and Co2+ Co-Doped TiO2 by Microemulsions

2007 ◽  
Vol 336-338 ◽  
pp. 1943-1945
Author(s):  
Wei Liang Liu ◽  
Dan Li Lu ◽  
Chang Chun Ge ◽  
Jian Hua Chen ◽  
Zhi Ping He
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Uv Light ◽  
Pure Tio2 ◽  
Doped Tio2 ◽  
Co Doped

La3+ and Co2+ co-doped titania nanoparticles were prepared from reacting TiOSO4, La(NO3)3 and Co(NO3)2 with NH4OH in water/Triton X-100/n-hexanol/cyclohexane microemulsions. The structure, surface morphology and the specific surface area of the samples were characterized. The photocatalytic efficiency of as-prepared TiO2 was tested by photodegrading methyl orange. The results showed that doping with La3+ and Co2+ could suppress the growth of TiO2 grains and increase the specific surface area; When the calcination temperature increased from 300°C to 900°C, the average crystallite size of the particles increased from 7.3nm to 35.6 nm andthe specific surface area of the particles decreased rapidly from 205.5m2/g to 41.2m2/g. The synthesized amorphous particles wer transformed into anatase phase at 300°C, and further into rutile phase at 900°C. UV-Vis diffuse reflectance spectrum revealed that La3+ and Co2+ co-doped TiO2 absorbed UV light and visible light, while pure TiO2 could only absorb UV light. In the experiments of photodegrading methyl orange, it was proved that La3+ and Co2+ co-doped TiO2 had high photocatalytic activity under UV light and visible light, while pure TiO2 showed photocatalytic activity just under UV light.

scholarly journals Utilization of Pharmaceutical Technology Methods for the Development of Innovative Porous Metasilicate Pellets with a Very High Specific Surface Area for Chemical Warfare Agents Detection

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1860
Author(s):  
Jiří Zeman ◽  
Sylvie Pavloková ◽  
David Vetchý ◽  
Adam Staňo ◽  
Zdeněk Moravec ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Uv Light ◽  
Detection System ◽  
Chemical Warfare Agents ◽  
High Specific Surface Area ◽  
Ammonium Bicarbonate ◽  
Toxic Substances ◽  
Pharmaceutical Technology

Pharmaceutical technology offers various dosage forms that can be applied interdisciplinary. One of them are spherical pellets which could be utilized as a carrier in emerging second-generation detection tubes. This detection system requires carriers with high specific surface area (SSA), which should allow better adsorption of toxic substances and detection reagents. In this study, a magnesium aluminometasilicate with high SSA was utilized along with various concentrations of volatile substances (menthol, camphor and ammonium bicarbonate) to increase further the carrier SSA after their sublimation. The samples were evaluated in terms of physicochemical parameters, their morphology was assessed by scanning electron microscopy, and the Brunauer–Emmett–Teller (BET) method was utilized to measure SSA. The samples were then impregnated with a detection reagent o-phenylenediamine-pyronine and tested with diphosgene. Only samples prepared using menthol or camphor were found to show red fluorescence under the UV light in addition to the eye-visible red-violet color. This allowed the detection of diphosgene/phosgene at a concentration of only 0.1 mg/m3 in the air for samples M20.0 and C20.0 with their SSA higher than 115 m2/g, thus exceeding the sensitivity of the first-generation DT-12 detection tube.

Synthesis of a novel visible light responsive γ-Fe2O3/SiO2/C-TiO2 magnetic nanocomposite for water treatment

2018 ◽  
Vol 78 (12) ◽  
pp. 2500-2510 ◽  
Author(s):  
Henry H. Mungondori ◽  
Spencer Ramujana ◽  
David M. Katwire ◽  
Raymond T. Taziwa
Keyword(s):  
Water Treatment ◽  
Visible Light ◽  
Surface Area ◽  
Fine Particles ◽  
Uv Light ◽  
Sol Gel ◽  
Spherical Shape ◽  
Solar Irradiation ◽  
Bet Surface Area ◽  
Average Pore

AbstractThis work investigates the preparation of a magnetically recoverable photocatalytic nanocomposite of maghemite nanoparticles coated with silica and carbon doped titanium dioxide. The novel nanocomposite boasts the advantages of efficient photocatalytic degradation of organic pollutants in water and ease of recovery of the fine particles after water treatment. The photocatalytic nanocomposite was successfully synthesized through a stepwise approach via co-precipitation and sol-gel methods. Characterisation by Fourier transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) substantiated the existence of the intended structure of the nanocomposite and the particles were found to be in the size range of 15–22 nm with a quasi-spherical shape. Brunauer–Emmett–Teller (BET) surface area analysis revealed an average surface area of 55.20 m2/g, which is higher than that of commercial TiO2 (Degussa P25, 50.00 m2/g), and an average pore diameter of 8.36 nm. A 5 ppm methylene blue solution was degraded with an efficiency of 96.8% after 3 h of solar irradiation, which was 19.7% greater than using the same photo-catalyst under strict UV light irradiation. Photo-catalysis using these nanoparticles was observed to be very effective. The prepared novel visible light active nanocomposite has great potential for incorporation into water treatment systems because it exhibits good stability and magnetism, as well as high photocatalytic efficiency.

Preparation of Nitrogen-Deficient Graphitic Carbon Nitride with a Large Specific Surface Area by Melt Pretreatment and Its Photocatalytic Performance

NANO ◽  
2020 ◽  
Vol 15 (06) ◽  
pp. 2050079
Author(s):  
Xuelei Li ◽  
Jinfeng Bai ◽  
Jiaqi Li ◽  
Chao Li ◽  
Junru Zhang ◽  
...  
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Nitride ◽  
Mesoporous Structure ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Large Specific Surface Area ◽  
X Ray

In this study, nitrogen-deficient graphitic carbon nitride (M-LS-g-C3N4) with a mesoporous structure and a large specific surface area was obtained by calcination after melt pretreatment using urea as a precursor. X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption, X-ray photoelectron spectroscopy (XPS), UV-Vis, ESR and photoluminescence (PL) were used to characterize the structure, morphology and optical performance of the samples. The TEM results showed the formation of a mesoporous structure on the 0.1[Formula: see text]M-LS-g-C3N4 surface. The porous structure led to an increase in the specific surface area from 41.5[Formula: see text]m2/g to 124.3[Formula: see text]m2/g. The UV-Vis results showed that nitrogen vacancies generated during the modification process reduced the band gap of g-C3N4 and improved the visible light absorption. The PL spectra showed that the nitrogen defects promoted the separation of photogenerated electron–hole pairs. In the visible light degradation of methyl orange (MO), the reaction rate constant of 0.1[Formula: see text]M-LS-g-C3N4 reached 0.0086[Formula: see text][Formula: see text], which was 5.05 times that of pure g-C3N4. Superoxide radicals and photogenerated holes were found to be the main active species in the reaction system. This study provides an efficient, green and convenient means of preparing graphitic carbon nitride with a large specific surface area.

Preparation, Characterization and Visible-Light Photocatalytic Properties of BiOCl/BiOI Nanocomposites

2012 ◽  
Vol 586 ◽  
pp. 10-17 ◽  
Author(s):  
Kai Jin Huang ◽  
Hou Guang Liu ◽  
Fang Li Yuan ◽  
Chang Sheng Xie
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Quantum Efficiency ◽  
Specific Surface Area ◽  
Light Absorption ◽  
Critical Factor ◽  
Photocatalytic Properties ◽  
Impregnation Method ◽  
Visible Light Photocatalytic

BiOCl/BiOI nanocomposites were synthesized using a thermal impregnation method for the first time. The intense visible-light absorption and large specific surface area gave 4wt.％BiOCl/BiOI nanocomposites the best visible-light photocatalytic properties among all the catalysts for the photodegradation of methyl orange,about 78％ after 2 h. But decreased activities were obtained with the increase of BiOCl content in the nanocomposites. Considering the light absorption,specific surface area and the quantum efficiency, the high recombination of the photoinduced electron-hole pairs of the catalysts that lowed the quantum efficiency was believed to be the critical factor for their decreased photocatalytic activities.

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