TiO2 mesocrystals built of nanocrystals with exposed {001} facets: facile synthesis and superior photocatalytic ability

2014 ◽  
Vol 2 (46) ◽  
pp. 19589-19593 ◽  
Author(s):  
Yanna Guo ◽  
Hui Li ◽  
Jin Chen ◽  
Xuejing Wu ◽  
Lei Zhou
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Crystallite Size ◽  
Surface Area ◽  
Crystallographic Orientation ◽  
Low Cost ◽  
Facile Synthesis ◽  
Photocatalytic Ability ◽  
Similar Crystallographic Orientation ◽  
The Relationship

A totally novel, extremely easy, much greener and low-cost method has been developed to synthesize TiO2 mesocrystals. These materials are built of TiO2 nanocrystals with similar crystallographic orientation and largely exposed {001} facets. Their unique structure optimizes the relationship between specific surface area, crystallite size and active facets, and therefore leads to superior photocatalytic activity.

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.

Bi2WO6 Nanoparticles Prepared by Combustion Synthesis with Different Fuels and their Photocatalytic Activity

2014 ◽  
Vol 604 ◽  
pp. 93-101
Author(s):  
Maris Kodols ◽  
Sabine Didrihsone ◽  
Janis Grabis
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Citric Acid ◽  
Ethylene Glycol ◽  
Specific Surface ◽  
Crystallite Size ◽  
Combustion Synthesis ◽  
Surface Area ◽  
Specific Surface Area ◽  
Solution Ph

The influence of glycine, glycerine, ethylene glycol and citric acid fuel and their ratio to NO3- on formation and dispersity of Bi2WO6 nanoparticles prepared by combustion synthesis has been studied. The pure crystalline Bi2WO6 with specific surface area 24,8 m2/g and crystallite size of 28 nm was obtained by using glycerine as fuel at its ratio to NO3- of 0,67. The photocatalytic activity of the prepared Bi2WO6 in degradation of methylene blue depended on its specific surface area of samples and solution pH.

scholarly journals Relationship between Synthesis Conditions and Photocatalytic Activity of Nanocrystalline TiO2

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Yosep Han ◽  
Hyung-Seok Kim ◽  
Hyunjung Kim
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Specific Surface ◽  
Crystallite Size ◽  
Surface Area ◽  
Calcination Temperature ◽  
Specific Surface Area ◽  
Molar Ratio ◽  
Hydroxyl Groups ◽  
Synthesis Conditions

The degradation efficiency of methylene blue by TiO2nanoparticles, which were synthesized under different synthesis conditions (i.e., molar ratio of water and titanium tetraisopropoxide (TTIP), pH, and calcination temperature) in a sol-gel process, was systematically investigated. The results showed that increasing the molar ratio of water and TTIP led to the enhanced photocatalytic activity of TiO2nanoparticles, which were likely attributed to the increased specific surface area of TiO2nanoparticles synthesized with high molar ratio. The results were supported by the relative increase in the size of interaggregated pores of the aggregated TiO2nanoparticles. The best photocatalytic activity of TiO2nanoparticles was observed at acidic synthesis conditions; however, the results were not consistent with physical properties for the crystallinity and the crystallite size of TiO2nanoparticles but rather explained by the presence of abundant hydroxyl groups and water molecules existing on the surface of TiO2under acidic synthesis environments. Furthermore, methylene blue degradation experiments revealed that the photocatalytic activity of TiO2nanoparticles was maximized at the calcination temperature of 700°C. The trend was likely due to the combined effect of the anatase crystallinity which showed the highest value at 700°C and the crystallite size/specific surface area which did not excessively increase up to 700°C.

One-step synthesis of spherical NaTaO3 and graphene spherical NaTaO3 nanoparticles with enhanced photocatalytic activity for NO purification

2018 ◽  
Vol 11 (04) ◽  
pp. 1850070 ◽  
Author(s):  
Zimao Ding ◽  
Sheng Guo ◽  
Xiaoyong Wu ◽  
Hussain Fida
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Uv Irradiation ◽  
Mixed Solution ◽  
One Pot ◽  
Photocatalytic Ability ◽  
Water Glycerol

To obtain efficient photocatalytic air purification, a series of NaTaO3 nanoparticles were successfully synthesized through a one-pot solvothermal approach, using water/glycerol mixed solution as solvent. The glycerol not only played an important role for controlling the morphology and particle size, but also remarkably enhanced the specific surface area of the as-prepared NaTaO3. Under optimal conditions, the spherical NaTaO3 (NaTaO3-30) exhibited much higher deNO[Formula: see text] performance under UV irradiation as compared to the cubic NaTaO3 (NaTaO3-0). Furthermore, the graphene spherical NaTaO3 composites were also prepared to further enhance the visible light driven photocatalytic ability of spherical NaTaO3. When 1[Formula: see text]wt.% graphene was loaded, the spherical NaTaO3/graphene showed excellent performance for continuous NO gas destruction under UV irradiation, short wavelength visible light ([Formula: see text][Formula: see text]nm) and even long wavelength visible light ([Formula: see text][Formula: see text]nm), which was superior to spherical NaTaO3 and cubic NaTaO3/graphene. The increased specific surface area, expanded light absorption and accelerated electron transport were responsible for the enhanced photocatalytic activity of the composite. The present work may shed new light on the synthesis of novel perovskite-type NaTaO3-based catalysts with excellent photocatalytic performance.

scholarly journals Nanocomposite Materials Based on Electrochemically Synthesized Graphene Polymers: Molecular Architecture Strategies for Sensor Applications

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 149
Author(s):  
André Olean-Oliveira ◽  
Gilberto A. Oliveira Brito ◽  
Celso Xavier Cardoso ◽  
Marcos F. S. Teixeira
Keyword(s):  
Conducting Polymers ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Electrochemical Sensors ◽  
Structural Characteristics ◽  
Low Cost ◽  
Large Specific Surface Area ◽  
Molecular Architecture ◽  
Sensor Applications

The use of graphene and its derivatives in the development of electrochemical sensors has been growing in recent decades. Part of this success is due to the excellent characteristics of such materials, such as good electrical and mechanical properties and a large specific surface area. The formation of composites and nanocomposites with these two materials leads to better sensing performance compared to pure graphene and conductive polymers. The increased large specific surface area of the nanocomposites and the synergistic effect between graphene and conducting polymers is responsible for this interesting result. The most widely used methodologies for the synthesis of these materials are still based on chemical routes. However, electrochemical routes have emerged and are gaining space, affording advantages such as low cost and the promising possibility of modulation of the structural characteristics of composites. As a result, application in sensor devices can lead to increased sensitivity and decreased analysis cost. Thus, this review presents the main aspects for the construction of nanomaterials based on graphene oxide and conducting polymers, as well as the recent efforts made to apply this methodology in the development of sensors and biosensors.

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 Optimized Synthesis Temperature and Time to Obtain Crystalline Carbon Nitride with Enhanced Photocatalytic Activity for Phenol Degradation

2020 ◽  
Vol 20 (6) ◽  
pp. 1392
Author(s):  
Leny Yuliati ◽  
Mohd Hayrie Mohd Hatta ◽  
Siew Ling Lee ◽  
Hendrik Oktendy Lintang
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Band Gap ◽  
Surface Area ◽  
Carbon Nitride ◽  
Phenol Degradation ◽  
Synthesis Temperature ◽  
Band Gap Energy ◽  
Synthesis Time ◽  
Gap Energy

In this work, the crystalline carbon nitride photocatalysts were synthesized by an ionothermal technique with varied synthesis temperature of 500, 550, and 600 °C, and synthesis time of 2, 4, and 6 h. Fourier transform infrared spectra showed the successful formation of the prepared carbon nitrides from their characteristic vibration peaks. X-ray diffraction patterns suggested that the same phase of poly(triazine imide) and heptazine could be observed, but with different crystallinity. The optical properties showed that different temperatures and synthesis time resulted in the different band gap energy (2.72–3.02 eV) as well as the specific surface area (24–73 m2 g–1). The transmission electron microscopy image revealed that the crystalline carbon nitride has a near-hexagonal prismatic crystallite size of about 50 nm. Analysis by high-performance liquid chromatography showed that the best photocatalytic activity for phenol degradation under solar light simulator was obtained on the crystalline carbon nitride prepared at the 550 °C for 4 h, which would be due to the high crystallinity, suitable low band gap energy (2.82 eV), and large specific surface area (73 m2 g–1). Controlling both the temperature and synthesis time is shown to be important to obtain the best physicochemical properties leading to high activity.

scholarly journals Flower-like boehmite nanopowders obtained at low temperature from Bayer liquor

2020 ◽  
Vol 14 (2) ◽  
pp. 168-172
Author(s):  
Marija Milanovic ◽  
Zoran Obrenovic ◽  
Ivan Stijepovic ◽  
Ljubica Nikolic
Keyword(s):  
Low Temperature ◽  
Specific Surface ◽  
Surface Area ◽  
Industrial Production ◽  
Single Phase ◽  
Low Cost ◽  
High Specific Surface Area ◽  
Nanocrystalline Powders ◽  
Transition Alumina ◽  
Bayer Liquor

Boehmite nanocrystalline powders were obtained by neutralization of Bayer liquor at 70?C with addition of glucose. Temperature of the neutralization induced formation of the flower-like morphology of the nanopowders. XRD and FTIR results confirmed that the single phase boehmite is formed without any other impurities. Calcination at 500?C led to the formation of transition -alumina with the retention of the flower-like morphology. Both as-synthesised and calcined powders possessed high specific surface area with mesopores between 3-6 nm in diameter. Relatively low temperature of neutralization as well as the use of low cost and ecologically friendly glucose as a surfactant are very promising for the possible application in the industrial production of alumina nanopowders.

Sign in / Sign up

Export Citation Format

Share Document