Synthesis and Photocatalytic Property of BiVO4/FeVO4 Composite Novel Photocatalyst

2010 ◽  
Vol 129-131 ◽  
pp. 784-788 ◽  
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Dong Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Photocatalytic Property ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Triclinic Phase ◽  
Xrd Patterns

BiVO4/FeVO4 composite photocatalyst samples were prepared by calcining the mixture of FeVO4 and BiVO4 precusor which were prepared through liquid phase precipitation method for further increasing the photocatalytic efficiency of FeVO4. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microsoope（SEM）and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. The XRD patterns indicate that BiVO4/FeVO4 composite photocatalysts consist of triclinic phase and the lattice was not distorted beacause of doping Bi. But the morphology change greatly and the specific surface area has little change. In the experimental conditions used, the optimal photocatalytic activity for all the prepared samples was reached when BiVO4 doping was 22 at%. The degradation rate of MO was increased by 20％ or so than that of pure FeVO4.

scholarly journals Preparation and photocatalytic activity of the layered titanates

2010 ◽  
Vol 4 (2) ◽  
pp. 69-73 ◽  
Author(s):  
Marija Milanovic ◽  
Ivan Stijepovic ◽  
Ljubica Nikolic
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Photocatalytic Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Bet Method ◽  
Ft Ir

Titanate structures were synthesized in highly alkaline solution using hydrothermal procedure. As-prepared powders were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). A specific surface area of the powders was measured by BET method. Results confirmed formation of layered trititanates, already after one hour of hydrothermal synthesis. To examine the photocatalytic activity of the as-prepared layered titanates, methylene blue (MB) was employed as a target compound in response to visible light at ambient temperature. It was observed that the specific surface area, size distribution and crystallinity are important factors to get high photocatalytic activity for the decomposition of MB. .

Influence of pH Value and Precipitant on Zn2SnO4 Formation via Co-Precipitation Method

2011 ◽  
Vol 291-294 ◽  
pp. 61-64
Author(s):  
Yu Shiang Wu ◽  
Min He Tsau
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ph Value ◽  
Particle Morphology ◽  
Nano Particles ◽  
Precipitation Method ◽  
Strong Base ◽  
Co Precipitation

Nanorod-shaped zinc stannate Zn2SnO4 (ZTO) with great photocatalytic activity was successfully synthesized via a co-precipitation method. In this paper, a strong base (NaOH) and a weak base (Na2CO3) are adopted as precipitants in order to form the precursor precipitate. The titration endpoints are fixed at pH6, pH8, and pH10 in order to adjust the solution precipitant quantity. Dependent variables above were not seen in other research before. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results show that the powders synthesized were ZTO nano-particles. Photocatalytic activity of the powders was measured utilizing a photocatalytic degradation reaction with methylene blue (MB) solution. The smallest particles were obtained by utilizing NaOH as a precipitant and adjusting pH to 6. Based on TEM images, the ZTO had nano-rod particle morphology. However, when precipitant Na2CO3 was utilized, particles agglomerated together, reducing specific surface area. Hence, the former sample shows better photocatalytic activity than the latter one. Consequently, powders titrated to pH6 by precipitant NaOH and calcined for 1 hour will form partly nano-rod particles with slight agglomeration, increasing the specific surface area of ZTO and bringing about the best photocatalytic characteristics.

scholarly journals MECHANOCHEMICAL SYNTHESIS OF CALCIUM TITANATE AND RESEARCH OF ITS PHOTOCATALYTIC ACTIVITY

2018 ◽  
Vol 59 (6) ◽  
pp. 83 ◽  
Author(s):  
Konstantin V. Ivanov ◽  
Alexandr V. Agafonov ◽  
Olyga V. Alexeeva
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Biological Tissues ◽  
Calcium Titanate ◽  
Ceramic Technology ◽  
X Ray Diffraction ◽  
X Ray

Recently much attention is paid to the synthesis and study of the properties of inorganic materials, based on alkaline earth titanates with a perovskite structure that have various polymorphic forms depending on the temperature. Calcium titatanat (CaTiO3) can be selected from the variety of perovskites because of its relatively high dielectric constant, unique photochemical properties, chemical stability, and compatibility with biological tissues, which leads to its application in microelectronics, photocatalysis and biomedicine as bone implants. In this paper, a solid-phase synthesis of calcium titanate was carried out by ceramic technology using mechanochemistry methods. This method allows to obtain calcium titanate directly by mechanochemical activation from the initial mixture of Ca (OH)2 and TiO2, which significantly reduces the energy consumption for its production. Structural changes in the synthesized material during calcination at 120 °C, 200 °C, 400 °C, 600 °C, and 800 °C were studied. The particle size and specific surface area of powders synthesized and calcined at 800 °C was measured by laser diffraction ("Analysette 22") and the low temperature (77K) nitrogen adsorption-desorption vapor, respectively. The phase composition of the obtained materials was studied by X-ray diffraction. It was found on the basis of studies of the particle size distribution that synthesized and calcined powders contain nanoparticles with sizes of 377 and 422 nm. The samples of CaTiO3 calcined at 120 °C and 800 °C have a mesoporous structure, the specific surface area was 46 and 7 m2/g, respectively, and average pore size in powders was 4 nm. It was found by the X-ray diffraction technique that the uncalcined sample contains admixtures of CaCO3 and TiO2 that can be removed completely at 600 °C.The photocatalytic activity of the synthesized material has been studied by the example of Rhodamine B dye decoloration on the calcium titanate calcined at 800°C. It was found that the decomposition degree of dye in solution was 77% for 80 min at a 6.7% shadow adsorption.

Preparation of Photocatalytic Porous Nano-ZnO from Galvanizing Dross

2019 ◽  
Vol 298 ◽  
pp. 186-194
Author(s):  
Peng Hui Wu ◽  
Jun Lin Xie ◽  
Jia Ming Yang ◽  
Wen Hao Yang ◽  
Chi Mao ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Calcination Temperature ◽  
Specific Surface Area ◽  
Hexagonal Wurtzite Structure ◽  
Growth Direction ◽  
X Ray Diffraction ◽  
Nano Zno ◽  
20 Nm

By using an acid free wet chemical method, porous nano-ZnO with high photocatalytic performance was synthesized from galvanizing dross at room temperature. The route is an environmental way to realize high value conversion and reuse of galvanizing dross. X-ray diffraction, microstructure, electron diffraction and specific surface area analyses show, the prepared porous nano-ZnOs are hexagonal wurtzite structure ZnO strips. The strips are consist of ZnO nanoparticles, the strips growth direction is perpendicularly to the C axis when the calcination temperature is up to 350°C. With the increase of calcination temperature, the specific surface area of ZnO decreases and the crystallinity increases. The photocatalytic activity of nano-ZnO is related to its crystallinity and grain size. When the calcination temperature is 400°C and the calcination time is 2h, the nano-ZnO has been completely crystallized, the ZnO particle size is uniform and is about 20 nm, the photocatalytic activity is the best and can reach up to 95%.

Synthesis of Novel Core-Shell Structured Hydroxyapatite/Meso-Silica for Removal of Methylene Blue from Aqueous Solutions

2012 ◽  
Vol 463-464 ◽  
pp. 543-547 ◽  
Author(s):  
Cheng Feng Li ◽  
Xiao Lu Ge ◽  
Shu Guang Liu ◽  
Fei Yu Liu
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
Precipitation Method ◽  
Core Shell ◽  
Adsorption Desorption

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.

scholarly journals Adsorption of pharmaceuticals from aqueous solutions using biochar derived from cotton gin waste and guayule bagasse

Biochar ◽  
2020 ◽  
Author(s):  
Marlene C. Ndoun ◽  
Herschel A. Elliott ◽  
Heather E. Preisendanz ◽  
Clinton F. Williams ◽  
Allan Knopf ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Functional Groups ◽  
Specific Surface Area ◽  
High Surface ◽  
Strong Interactions ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Cotton Gin Waste ◽  
Cotton Gin

Abstract Biochars produced from cotton gin waste (CG) and guayule bagasse (GB) were characterized and explored as potential adsorbents for the removal of pharmaceuticals (sulfapyridine-SPY, docusate-DCT and erythromycin-ETM) from aqueous solution. An increase in biochar pyrolysis temperature from 350 οC to 700 οC led to an increase in pH, specific surface area, and surface hydrophobicity. The electronegative surface of all tested biochars indicated that non-Coulombic mechanisms were involved in adsorption of the anionic or uncharged pharmaceuticals under experimental conditions. The adsorption capacities of Sulfapyridine (SPY), Docusate (DCT) and Erythromycin (ETM) on biochar were influenced by the contact time and solution pH, as well as biochar specific surface area and functional groups. Adsorption of these pharmaceutical compounds was dominated by a complex interplay of three mechanisms: hydrophobic partitioning, hydrogen bonding and π–π electron donor–acceptor (EDA) interactions. Despite weaker π–π EDA interactions, reduced hydrophobicity of SPY− and increased electrostatic repulsion between anionic SPY− and the electronegative CG biochar surface at higher pH, the adsorption of SPY unexpectedly increased from 40% to 70% with an increase in pH from 7 to 10. Under alkaline conditions, adsorption was dominated by the formation of strong negative charge-assisted H-bonding between the sulfonamide moiety of SPY and surface carboxylic groups. There seemed to be no appreciable and consistent differences in the extent of DCT and ETM adsorption as the pH changed. Results suggest the CG and GB biochars could act as effective adsorbents for the removal of pharmaceuticals from reclaimed water prior to irrigation. High surface area biochars with physico-chemical properties (e.g., presence of functional groups, high cation and anion exchange capacities) conducive to strong interactions with polar-nonpolar functionality of pharmaceuticals could be used to achieve significant contaminant removal from water. Graphic Abstract

Photocatalytic Efficiency for Dye Decolorization of the UV/TiO2, UV/TiO2 + In2O3 and UV/TiO2-In2O3 Systems

2013 ◽  
Vol 831 ◽  
pp. 263-266
Author(s):  
Chung Hsin Wu ◽  
Chao Yin Kuo ◽  
Chih Hao Lai ◽  
Wei Yang Chung
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Dye Decolorization ◽  
X Ray Diffraction ◽  
First Order ◽  
First Order Kinetics ◽  
Vis Spectroscopy ◽  
Reactive Red 2

This study explored the decolorization of C.I. Reactive Red 2 (RR2) by the ultraviolet (UV)/TiO2, UV/TiO2 + In2O3, and UV/TiO2-In2O3 systems. The TiO2-In2O3 was generated by the sol-gel method and TiO2 + In2O3 was created by mixing TiO2 and In2O3 powders. The surface properties of TiO2, In2O3, and TiO2-In2O3 were analyzed by X-ray diffraction, a specific surface area analyzer, UV-vis spectroscopy, and scanning electron microscopy. The specific surface area of TiO2, In2O3, and TiO2-In2O3 was 29.5, 44.6, and 35.7 m2/g, respectively; additionally, the band gap of TiO2, In2O3, and TiO2-In2O3 was 2.95, 2.64, and 2.91 eV; respectively. The decolorization rate constant fit pseudo-first-order kinetics and that of the UV/TiO2, UV/TiO2 + In2O3, and UV/TiO2-In2O3 systems was 0.0023, 0.0031, and 0.0072 min-1; respectively.

Facile synthesis of novel Roe-like TiO2 hollow nanospheres with mesoporous cavity for improved photocatalytic activity

2017 ◽  
Vol 10 (03) ◽  
pp. 1750028 ◽  
Author(s):  
Yan Zhu ◽  
Xiaoxia Yan ◽  
Yuanxin Ge ◽  
Shumin Wang ◽  
Dongmei Deng ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Self Assembly ◽  
Charge Separation ◽  
Synergistic Effects ◽  
Assembly Process ◽  
Hollow Nanospheres ◽  
Facile Synthesis

A facile approach was developed to synthesize novel Roe-like TiO2 hollow nanospheres via a template-assisted self-assembly process. These TiO2 nanospheres possessing mesoporous cavity manifest significantly improved photocatalytic activity owing to the synergistic effects of increased charge separation, more efficient use of the light and specific surface area.

Ultrasonic-Microwave Synergistic Synthesis of RGO–Bi2WO6 Photocatalyst with High Photoactivity for Basic Nitrogen Compounds in Light Oil

NANO ◽  
2016 ◽  
Vol 11 (05) ◽  
pp. 1650052 ◽  
Author(s):  
Ying Chen ◽  
Shenglun Ji ◽  
Tengfei Qiao ◽  
Shuang Miao ◽  
Yu Zhao
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Composite Catalyst ◽  
Photogenerated Carrier ◽  
X Ray Diffraction ◽  
Composite Photocatalyst ◽  
Photocatalytic Activities ◽  
Light Oil ◽  
Ft Ir

Graphene–Bi2WO6 composite photocatalyst with excellent photocatalytic properties were synthetized by ultrasonic-microwave synergistic method. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier infrared (FT-IR) spectrum, specific surface area analyzer (BET) and UV-Vis diffuse reflectance spectra. The photocatalytic activities of as-prepared samples were evaluated by degradation of pyridine in light oil under visible light irradiation. The results show that graphene changed appearance structure of Bi2WO6, which prevented the Bi2WO6 nanosheets reunion arrangement, and increased specific surface area of the catalyst. It can also reduce the recombination probability of photogenerated carrier, so as to improve the photocatalytic activity of the composite catalyst. The optimal amount of graphene is 2%, with the denitrification rate as high as 89.28%, much higher than that of pure Bi2WO6.

Study of Heating Effect on Specific Surface Area, and Changing Optical Properties of ZnO Nanocrystals

2011 ◽  
Vol 403-408 ◽  
pp. 1205-1210
Author(s):  
Jaleh Babak ◽  
Ashrafi Ghazaleh ◽  
Gholami Nasim ◽  
Azizian Saeid ◽  
Golbedaghi Reza ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Energy Gap ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zno Nanocrystals ◽  
Transmission Electron ◽  
Zno Nanocrystal

In this work ZnO nanocrystal powders have been synthesized by using Zinc acetate dehydrate as a precursor and sol-gel method. Then the products have been annealed at temperature of 200-1050°C, for 2 hours. The powders were characterized using X-ray diffraction (XRD), UV-vis absorption and photoluminescence (PL) spectroscopy. The morphology of refrence ZnO nanoparticles have been studied using Transmission Electron Microscope (TEM). During the annealing process, increase in nanocrystal size, defects and energy gap quantitative, and decrease in specific surface area have been observed.

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