Hydrothermal Splitting of Titanate Fibers to Single-Crystalline TiO2 Nanostructures with Controllable Crystalline Phase, Morphology, Microstructure, and Photocatalytic Activity

2008 ◽  
Vol 112 (24) ◽  
pp. 8809-8818 ◽  
Author(s):  
Liming Shen ◽  
Ningzhong Bao ◽  
Yanqing Zheng ◽  
Arunava Gupta ◽  
Taicheng An ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Crystalline Phase ◽  
Phase Morphology ◽  
Single Crystalline ◽  
Tio2 Nanostructures

Preparation of Macroprous C12A7 Mayenite Monoliths via a Sol-Gel Process with Nitrates as Precursors

2018 ◽  
Vol 768 ◽  
pp. 211-217 ◽  
Author(s):  
Rui Wang ◽  
Yu Kun Sun ◽  
Bao Jia Qi Jiang ◽  
Hui Yang ◽  
Xing Zhong Guo
Keyword(s):  
Heat Treatment ◽  
Phase Separation ◽  
Binary System ◽  
Propylene Oxide ◽  
Crystalline Phase ◽  
Sol Gel ◽  
Single Crystalline ◽  
Sol Gel Process

Macroporous Ca12Al14O33(C12A7) mayenite monoliths have been successfully prepared via a sol-gel process in the presence of propylene oxide (PO) and poly (ethyleneoxide) (PEO). Gelation of CaO-Al2O3binary system with nitrates salts as additional precursors is accelerated by PO as an acid scavenger, while PEO works as a phase separation inducer to mediate the phase separation of the system. Appropriate PO and PEO amounts allow the formation of monolithic xerogel with interconnected macropores and co-continuous skeletons. The resultant dried gels are amorphous and the single crystalline phase Ca12Al14O33mayenite forms after heat-treatment at 1100 °C in air, while the macrostructure is preserved with a porosity as high as 78% and smoother and denser skeletons.

Zeolite Syntheses from Superalkaline Reaction Mixtures

1992 ◽  
Vol 57 (4) ◽  
pp. 788-793 ◽  
Author(s):  
Falk Fischer ◽  
Marianne Hadan ◽  
Günter Fiedrich
Keyword(s):  
Ir Spectroscopy ◽  
Crystalline Phase ◽  
Ion Concentration ◽  
Single Crystalline ◽  
Hydroxyl Ion ◽  
Type Zeolite

The synthesis of faujasite-type zeolite from superalkaline reaction mixtures are described. The contribution shows the influence of component K2O added in the system Na2O-Al2O3-SiO2-H2O with H2O/(K2O + Na2O) = 13-15. The reaction course was investigated in the range K2O/(K2O + Na2O) from about 0.07 to 0.5. Under used conditions it is quite possible to isolate faujasite-type zeolite as a single crystalline phase. By means of IR spectroscopy, low SiO2/Al2O3 ratios from 2.0 to 2.1 in the faujasite framework have been indicated. The low SiO2/Al2O3 ratios are interpreted by a higher stability of the Si-O-Al- than the Si-O-Si- bond with increasing hydroxyl ion concentration.

Single-Crystalline-Phase Mo3VOx: An Efficient Catalyst for the Partial Oxidation of Acrolein to Acrylic Acid

ChemCatChem ◽  
2013 ◽  
Vol 5 (10) ◽  
pp. 2869-2873 ◽  
Author(s):  
Chen Chen ◽  
Nakatani Kosuke ◽  
Toru Murayama ◽  
Wataru Ueda
Keyword(s):  
Acrylic Acid ◽  
Partial Oxidation ◽  
Crystalline Phase ◽  
Efficient Catalyst ◽  
Single Crystalline

scholarly journals 1D TiO2 Nanostructures Prepared from Seeds Presenting Tailored TiO2 Crystalline Phases and Their Photocatalytic Activity for Escherichia coli in Water

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Julieta Cabrera ◽  
Dwight Acosta ◽  
Alcides López ◽  
Roberto J. Candal ◽  
Claudia Marchi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Photocatalytic Activity ◽  
Bactericidal Activity ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
E Coli ◽  
1D Nanostructures ◽  
Sol Gel Synthesis ◽  
Hydrolysis Of ◽  
Tio2 Nanostructures

TiO2 nanotubes were synthesized by alkaline hydrothermal treatment of TiO2 nanoparticles with a controlled proportion of anatase and rutile. Tailoring of TiO2 phases was achieved by adjusting the pH and type of acid used in the hydrolysis of titanium isopropoxide (first step in the sol-gel synthesis). The anatase proportion in the precursor nanoparticles was in the 3–100% range. Tube-like nanostructures were obtained with an anatase percentage of 18 or higher while flake-like shapes were obtained when rutile was dominant in the seed. After annealing at 400°C for 2 h, a fraction of nanotubes was conserved in all the samples but, depending on the anatase/rutile ratio in the starting material, spherical and rod-shaped structures were also observed. The photocatalytic activity of 1D nanostructures was evaluated by measuring the deactivation of E. coli in stirred water in the dark and under UV-A/B irradiation. Results show that in addition to the bactericidal activity of TiO2 under UV-A illumination, under dark conditions, the decrease in bacteria viability is ascribed to mechanical stress due to stirring.

Facet effect of TiO2 nanostructures from TiOF2 and their photocatalytic activity

2021 ◽  
Vol 404 ◽  
pp. 126493 ◽  
Author(s):  
Marta Kowalkińska ◽  
Szymon Dudziak ◽  
Jakub Karczewski ◽  
Jacek Ryl ◽  
Grzegorz Trykowski ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Tio2 Nanostructures

scholarly journals Crystalline phase regulation of anatase–rutile TiO2 for the enhancement of photocatalytic activity

RSC Advances ◽  
2020 ◽  
Vol 10 (71) ◽  
pp. 43592-43598
Author(s):  
Kuang Wang ◽  
Yan Zhuo ◽  
Jiayi Chen ◽  
Dawei Gao ◽  
Yu Ren ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Photocatalytic Activity ◽  
Nitric Acid ◽  
Crystalline Phase ◽  
Crystalline Phases ◽  
Rutile Tio2 ◽  
Potassium Titanate ◽  
Phase Regulation ◽  
Calcination Method

Biphasic TiO2 with adjustable crystalline phases was prepared by the hydrothermal-calcination method assisted by nitric acid (HNO3) and hydrogen peroxide (H2O2), using potassium titanate oxalate (K2TiO(C2O4)2) as the titanium source.

Sign in / Sign up

Export Citation Format

Share Document