scholarly journals Photocatalytic activity of BiFeO3/ZnFe2O4 nanocomposites under visible light irradiation

RSC Advances ◽  
2018 ◽  
Vol 8 (13) ◽  
pp. 6988-6995 ◽  
Author(s):  
B. Safizade ◽  
S. M. Masoudpanah ◽  
M. Hasheminiasari ◽  
A. Ghasemi
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Photocatalytic Efficiency

BiFeO3-25 wt% ZnFe2O4 exhibits a low specific surface area, high magnetization, and maximum photocatalytic efficiency of 97%.

scholarly journals Synthesis of Ag3PO4 using Hydrophylic Polymer and Their Photocatalytic Activities under Visible Light Irradiation

2017 ◽  
Vol 12 (2) ◽  
pp. 206 ◽  
Author(s):  
Uyi Sulaeman ◽  
Bin Liu ◽  
Shu Yin ◽  
Tsugio Sato
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Visible Light Irradiation ◽  
Photoelectron Spectroscopy ◽  
Light Irradiation ◽  
X Ray ◽  
Photocatalytic Activities

The highly active Ag3PO4 photocatalysts were successfully synthesized using the hydrophylic polymer of PVA (polyvinyl alcohol), PEG (polyethylene glycol) and PVP (polyvinyl pyrrolidone). The products were characterized using X-ray diffraction (XRD), Diffuse reflection spectroscopy (DRS), Field emission scanning electron microscope (FE-SEM), Brunauer–Emmett–Teller (BET) specific surface area, and X-ray photoelectron spectroscopy (XPS). Photocatalytic activities were evaluated using decomposition of Rhodamine B (RhB) under visible light irradiation. The results showed that the PVA, PEG, and PVP increased the specific surface area and enhanced the photocatalytic activity of Ag3PO4. The highest photocatalytic activity could be observed in Ag3PO4 synthesized with PVA, mainly due to an increase in electron excitation induced by PVA chemically adsorbed on the surface. Copyright © 2017 BCREC Group. All rights reservedReceived: 13rd November 2016; Revised: 10th February 2017; Accepted: 10th February 2017How to Cite: Sulaeman, U., Liu, B., Yin, S., Sato, T. (2017). Synthesis of Ag3PO4 using Hydrophylic Polymer and Their Photocatalytic Activities under Visible Light Irradiation. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2): 206-211 (doi:10.9767/bcrec.12.2.767.206-211)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.767.206-211 

Enhanced photocatalytic activity of a hollow TiO2–Au–TiO2 sandwich structured nanocomposite

RSC Advances ◽  
2016 ◽  
Vol 6 (23) ◽  
pp. 18958-18964 ◽  
Author(s):  
Qianqian Ding ◽  
Yunxia Zhang ◽  
Guozhong Wang ◽  
Hongjian Zhou ◽  
Haimin Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Large Specific Surface Area

The hollow mesoporous TiO2–Au–TiO2 nanospheres with stability, large specific surface area can enhance visible-light-induced photocatalytic activity.

scholarly journals Photocatalytic degradation of metoxuron in aqueous suspensions ofTiO2. Analytical and kinetic studies

2002 ◽  
Vol 4 (4) ◽  
pp. 147-151 ◽  
Author(s):  
Amina Amine Khodja ◽  
Bernadette Lavedrine ◽  
Claire Richard ◽  
Tahar Sehili
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Photocatalytic Degradation ◽  
Surface Area ◽  
Specific Surface Area ◽  
Kinetic Studies ◽  
Photocatalytic Efficiency ◽  
Aqueous Suspensions ◽  
Degussa P25 ◽  
Ring Hydroxylation

The photocatalytic degradation of metoxuron [3-(3-chloro-4-methoxyphenyl)-1,1-dimethylurea] in aqueous suspensions ofTiO2was investigated. Several intermediate photoproducts were identified using NMR and MS techniques. Oxidation or removal of the methyl of terminal nitrogen and ring hydroxylation were found to occur. 2-Propanol was shown to decrease the rate of photocatalytic degradation, inhibiting partly ring hydroxylation and completely reactions on terminal nitrogen. In contrast, basification of the suspensions accelerated the degradation significantly. Degussa P25TiO2was found to exhibit a higher photocatalytic activity than MillenniumTiO2in spite of a generally smaller specific surface area. Within the MillenniumTiO2series, the photocatalytic efficiency increased with the specific surface area.

TiO2 composite films on different substrates with enhanced visible light photocatalytic performance

2020 ◽  
Vol 13 (07) ◽  
pp. 2051037
Author(s):  
Ke Han ◽  
Guobao Li ◽  
Fang Li ◽  
Mingming Yao
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Composite Films ◽  
Methyl Green ◽  
Photogenerated Electrons

For the sake of improving the photocatalytic performance of TiO2, we prepared the B/Ag/Fe tridoped TiO2 films on common glass and stone substrates by the sol–gel method. In this work, the optical absorption, recombination of photogenerated electrons (e−) and holes (h[Formula: see text]), crystal types, thermal stability, composition, specific surface area and photocatalytic activity of the modified TiO2 films were investigated. The results indicated that B/Ag/Fe tridoping not only enhanced the absorption of visible light by TiO2, but inhibited the recombination of electron–hole (e−/h[Formula: see text]) pairs. The tridoping also promoted the formation of anatase and prevented the transformation of anatase to rutile at high temperature. The composite TiO2 has a large specific surface area, about three times that of pure TiO2. The photocatalytic activity of the TiO2 films were evaluated by methyl green (MG) and formaldehyde degradation. In all samples, the B/Ag/Fe tridoped TiO2 film exhibited the highest degradation rate of MG under both ultraviolet and visible light irradiation. The improvement of photocatalytic performance of TiO2 films is due to the synergistic effect of the B/Ag/Fe tridoping, which enhances the absorption of visible light and prolongs the lifetime of e−/h[Formula: see text] pairs and facilitates transfer of interface charge.

scholarly journals Gemini surfactant abetted synthesis of mesoporous Mn/Mg bimetal doped TiO2 nanomaterial: Characterization and photocatalytic activity studies under visible light irradiation

2020 ◽  
Author(s):  
Sankara Rao Miditana ◽  
Siva Rao Tirukkovalluri ◽  
Imandi Manga Raju ◽  
Shaik Abdul Alim ◽  
Genji Jaishree ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Surface Area ◽  
Visible Light Irradiation ◽  
Gemini Surfactant ◽  
Light Irradiation ◽  
Oh Radicals ◽  
X Ray ◽  
Ft Ir

Abstract The present work mainly aimed to synthesize different weight percentages (0.25-1.00 wt%) of Manganese (Mn2+) and Magnesium (Mg2+) bimetal ions doped TiO2 nanomaterial assisted with different weight percentages (5-15 wt%) of Gemini Surfactant (GS) using sol-gel method. The bimetal doped and undoped TiO2 photocatalysts were characterized by X-ray Diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), UV-Visible Diffused Reflectance Spectroscopy, Transmission Electron Microscopy, Brunauer-Emmett-Teller surface area analyzer, and Photoluminescence Spectroscopy. Characterization results evinced that Mn2+/Mg2+ bimetal ions doping and encapsulation of GS on TiO2 nanoparticles promote the formation of mesoporous multi-particle anatase TiO2 nanocatalysts with a narrowed band gap, less particle size, and high surface area. The surface elemental composition of the 0.25 wt% Mn2+& 1.00 wt% Mg2+ bimetal doped TiO2 in presence of 10 wt% of Gemini surfactant (after calcination) revealed the presence of both the metal dopants Mn2+ and Mg2+ along with the Ti and O and their chemical interactions were further confirmed by FT-IR results. The photocatalytic activity of these catalysts was assessed by the degradation of Methyl Red (MR) using visible light irradiation. To understand the effect of different reaction parameters on the photocatalytic activity of the nanocatalysts such as the dopant concentration, GS concentration, catalyst dosage, solution pH, and initial dye concentrations were investigated and optimized to achieve the best performance. The photoluminescence results conclude that OH radicals are the crucial reactive species responsible for oxidative photocatalytic degradation of MR.

New Silica Supported Titanium Dioxide Catalysts: Characteristics and Photocatalytic Efficiency in Waste Water Depollution

2006 ◽  
Vol 61 (10) ◽  
pp. 1311-1318 ◽  
Author(s):  
Noureddine Kamil ◽  
Mohamed Khalid El Amrani ◽  
Najiba Benjelloun
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Calcination Temperature ◽  
Specific Surface Area ◽  
Inductively Coupled Plasma ◽  
Aqueous Suspension ◽  
Textile Dye ◽  
Photocatalytic Efficiency

Silica gel supported titanium dioxide photocatalysts were prepared by sintering TiO2/SiO2 mixtures under variations of TiO2 content, calcination temperature and calcination time. The method allowed to obtain catalyst samples, which can be used in aqueous suspension and which were found to be easily separated by decantation after the photocatalytic treatment. The photocatalytic efficiency of the catalysts was tested by carrying out the photooxidation of the textile dye Acid Red 88 (AR88) in aqueous solution, used as “model” water pollutant. The obtained photoefficiency results were correlated to catalyst physicochemical characteristics, as determined by Inductively Coupled Plasma (ICP) analysis, X-ray diffraction, specific surface area (BET) and scanning electron microscopy (SEM). No positive correlation has been observed between titanium dioxide content and photocatalytic efficiency. The decrease of photocatalytic activity at high calcination temperature (1000 °C) is attributed to the phase transition anatase/rutile as well as to the decreasing specific surface area. According to SEM analysis, no significant fixation of TiO2 on silica is observed for catalysts prepared at low temperature (400 °C). The observed photocatalytic activity is consequently due to free TiO2 particles. The best efficiency is observed for photocatalyst prepared at 800 °C and containing around fifty percent titanium dioxide.

scholarly journals Three-Dimensional Zn0.5Cd0.5S/Reduced Graphene Oxide Hybrid Aerogel: Facile Synthesis and the Visible-Light-Driven Photocatalytic Property for Reduction of Cr(VI) in Water

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Wei Xiao ◽  
Wenjie Zhou ◽  
Yanhua Zhang ◽  
Liangliang Tian ◽  
Hongdong Liu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Visible Light ◽  
Specific Surface ◽  
Reduced Graphene Oxide ◽  
Surface Area ◽  
Specific Surface Area ◽  
Three Dimensional ◽  
Reduced Graphene ◽  
Visible Light Driven

A series of three-dimensional ZnxCd1-xS/reduced graphene oxide (ZnxCd1-xS/RGO) hybrid aerogels was successfully synthesized based on a one-pot hydrothermal approach, which were subsequently used as visible-light-driven photocatalysts for photoreduction of Cr(VI) in water. Over 95% of Cr(VI) was photoreduced by Zn0.5Cd0.5S/RGO aerogel material within 140 min, and such photocatalytic performance was superior to that of other ZnxCd1-xS/RGO aerogel materials (x≠0.5) and bare Zn0.5Cd0.5S. It was assumed that the enhanced photocatalytic activity of Zn0.5Cd0.5S/RGO aerogel was attributed to its high specific surface area and the preferable synergetic catalytic effect between Zn0.5Cd0.5S and RGO. Besides, Zn0.5Cd0.5S/RGO aerogel materials were robust and durable enough so that they could be reused several times with merely limited loss of photocatalytic activity. The chemical composition, phase, structure, and morphology of Zn0.5Cd0.5S/RGO aerogel material were carefully examined by a number of techniques like XRD, SEM, TEM, BET, Raman characterizations, and so on. It was found that Zn0.5Cd0.5S/RGO aerogel possessed hierarchically porous architecture with the specific surface area as high as 260.8 m2 g−1. The Zn0.5Cd0.5S component incorporated in Zn0.5Cd0.5S/RGO aerogel existed in the form of solid solution nanoparticles, which were uniformly distributed in the RGO matrix.

scholarly journals Development of a novel photocatalyst for the photocatalytic treatment of industrial wastewater

2021 ◽  
Author(s):  
Mohsen Nasirian
Keyword(s):  
Photocatalytic Activity ◽  
Transition Metal ◽  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mass Ratio ◽  
Thermal Synthesis ◽  
Composite Photocatalyst ◽  
X Ray

Heterogeneous semiconductor photocatalysts have been shown to be efficient for the degradation of refractory organics into simple compounds. Among all photocatalysts, TiO2 is the most used one. Two issues that arise with the use of unmodified TiO2 as a photocatalyst are the unwanted fast recombination of electron/hole pairs and the lower effectiveness in the presence of visible light irradiation. Doping a transition metal or a non-metal into TiO2 and its combination with another photocatalyst have been used to enhance its photoactivity. This study is to develop a new photocatalyst by the combination of TiO2 with another semiconductor oxide (Fe2O3) and its doping with transition metal such as Ag. Combined photocatalysts of Fe2O3 /TiO2 (with different mass ratio of Fe:TiO2) is synthesized and then silver ion is doped to combine photocatalysts (with different mass ratio of Ag:TiO2) to produce a new composite photocatalyst of Ag/TiO2/Fe2O3. A new method of UV-assisted thermal synthesis is also employed to prepare the new composite photocatalyst. Methyl orange (MO) and Congo red (CR), as model pollutants, are used to test the developed photocatalyst. In addition, nitrogen-doped titanium dioxide photocatalyst (N-TiO2) with heterojunction structures is synthesized by three different approaches including new UV-assisted thermal synthesis, annealing, and microwave techniques. The novel UV-assisted thermal synthesis has produced encouraging results as a preparation method to prepare N-TiO2 at lower temperature and atmospheric pressure as well as a lower cost. Design of Experiment (DOE) along with response surface methodology (RSM) is used to optimize the photocatalytic activity of N-TiO2 as well as the affecting parameters (wavelength, light intensity, pH, and initial TOC) for decomposition of organics. The structure of all synthesized composite photocatalysts are investigated by X-ray diffraction (XRD). Scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDS) is employed to evaluate surface characteristics and elemental analysis of synthesized photocatalysts. Specific surface area of photocatalysts is measured based on Brunauer, Emmett and Teller (BET) technique. Results show that bare TiO2 has the lowest photocatalytic activity in degradation of organics. When silver is doped to TiO2, the degradation of MO is slightly enhanced at specific mass ratio. The presence of Fe2O3 in the new composite causes a red shift and enhances the potential to absorb higher range of visible light. Results from XRD confirmed that Fe3+ substitutes with Ti4+ in the crystal lattice of TiO2 and crystal defect occurs. The degradation of MO in presence of Ag/TiO2/Fe2O3 (Ag/TiO2=0.005 w:w and Fe:TiO2= 0.01 w:w) reached to 95.6% under sunlight in three hours with a red shift towards visible light. It is observed that there is an optimum specific surface area of photocatalysts by doping and combining photocatalysts.

scholarly journals Gemini surfactant assisted synthesis of mesoporous Mn/Mg bimetal doped TiO2 nanomaterial: Characterization and photocatalytic activity studies under visible light irradiation

2021 ◽  
Author(s):  
Sankara Rao Miditana ◽  
Siva Rao Tirukkovalluri ◽  
Imandi Manga Raju ◽  
Shaik Abdul Alim ◽  
Genji Jaishree ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Surface Area ◽  
Visible Light Irradiation ◽  
Gemini Surfactant ◽  
Light Irradiation ◽  
Methyl Red ◽  
X Ray ◽  
Ft Ir

Abstract The present work mainly aimed to synthesize different weight percentages (0.25-1.00 wt%) of Manganese (Mn2+) and Magnesium (Mg2+) bimetal ions doped TiO2 nanomaterial assisted with different weight percentages (5-15 wt%) of Gemini surfactant (GS) using sol-gel method. The bimetal doped and undoped TiO2 photocatalysts were characterized by X-ray Diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), UV-Visible Diffused Reflectance Spectroscopy, Transmission Electron Microscopy, Brunauer-Emmett-Teller surface area analyzer, and Photoluminescence Spectroscopy. Characterization results revealed that mesoporous multi-particle anatase TiO2 nanoparticles with a narrowed band gap, small particle size, and high surface area were formed due to the combined effect of Mn2+/Mg2+ bimetal ions doping and effective encapsulation of GS over the initially formed TiO2 nanoparticles. The surface elemental composition of the 0.25 wt% Mn2+ and 1.00 wt% Mg2+ bimetal doped TiO2 in the presence of 10 wt% of GS (after calcination) revealed the presence of both the metal dopants Mn2+ and Mg2+ along with the Ti and O and their chemical interactions were further confirmed by FT-IR results. The photocatalytic activity of these catalysts was assessed by the degradation of Methyl Red using visible light irradiation. To understand the effect of different reaction parameters on the photocatalytic activity of the nanocatalysts such as the dopant concentration, surfactant concentration, catalyst dosage, solution pH, and initial dye concentrations were investigated and optimized to achieve the best performance. The photoluminescence results conclude that OH radicals are the crucial reactive species responsible for oxidative photocatalytic degradation of Methyl Red.

scholarly journals The Simplest Way to Iodine-Doped Anatase for Photocatalysts Activated by Visible Light

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Václav Štengl ◽  
Tomáš Matys Grygar
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Aqueous Suspension ◽  
Organometallic Compounds ◽  
Orange Ii ◽  
Iodine Doping ◽  
Doped Titania

Iodine-doped TiO2was prepared by thermal hydrolysis of aqueous solutions of the titanium peroxo-complex, which includes no organic solvents or organometallic compounds. The synthesized samples were characterized by X-ray diffraction (XRD), Raman spectroscopy (RS), infrared spectroscopy (IR), specific surface area (BET), and porosity determination (BJH). The morphology and particle size was determined by high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). All prepared samples have a red-shifted band-gap transition, well crystalline anatase structure, and porous particles with a 100–200 m2 g−1specific surface area. The photocatalytic activity of iodine-doped titania samples was determined by decomposition of Orange II dye during irradiation at 365 nm and 400 nm. Iodine doping promotes the titania photocatalytic activity very efficiently under visible light irradiation. The titania sample with 0.32 wt.% I has the highest catalytic activity during the photocatalyzed degradation of Orange II dye in an aqueous suspension in the UV and visible regions.

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