I am trying the sol-gel process using TTIP as the precursor, with Ethanol and HCl. however, the annealing furnace is out of order. Can anybody suggest some alternate method?
Calcination process is an indispensable part of the synthesis of TiO2 in the form of anatase. In the course of any liquid phase process (wet chemistry), you will receive imprecise product: hydroxide-hydrate Ti(OH)4 * nH2O with huge excess of water. The task of annealing is to remove water (both hydrate and constitutional), and to form a crystalline structure (if you really need an anatase structure). Solid state chemistry does not exist without annealing...
Even if you receive the product in a non-aqueous media, it will be necessary to remove rest of the solvent (as well as tracks of water, of course). This can be done by storage of the sample for several million years. If you have such time.
Hello,
you can used sol gel method... the white powder that occurred as final compound is directly anatase..... See the attachment file (CH2).
In the sol-gel process hydroxides, such as Ti(OH)4, are the normal precipitated form and heat is required to convert this form to a TiO2 allotrope. I'm suspicious of any claims that the oxide can be formed directly (indeed I can't seem to open the file attached by Luma in the post above this one). Be aware that the term 'nanopowder' is an oxymoron. Any powder produced is a collection of fused sub- and post-micron aggregates and agglomerates.
You could buy in a powder such as P25 TiO2.... This is the easiest route of preparation.
Thank you for all the reply. Luma, I cannot open your paper. Alan F Rawle will you be kind enough to explain the role of high temperature in deciding TiO2 particle crystallinity? I guess hydrothermal method also needs a 240 degree temp exposure. I found few references not involving annealing condition, but I am doubtful about the end result.
Luma M. Ahmed Thanks for the paper. But you have used the calcination process at 600-800 degrees.
Calcination process is an indispensable part of the synthesis of TiO2 in the form of anatase. In the course of any liquid phase process (wet chemistry), you will receive imprecise product: hydroxide-hydrate Ti(OH)4 * nH2O with huge excess of water. The task of annealing is to remove water (both hydrate and constitutional), and to form a crystalline structure (if you really need an anatase structure). Solid state chemistry does not exist without annealing...
Even if you receive the product in a non-aqueous media, it will be necessary to remove rest of the solvent (as well as tracks of water, of course). This can be done by storage of the sample for several million years. If you have such time.
Swayamprava Dalai
Look at the phase diagram for TiO2. This explains the stability under conditions of differing temperature and pressure. For example the attached from DOI: 10.1155/2009/294042
Also see the bottom of page 719 in this NBS publication from 1933.
OK, I've renamed the file from Luma M. Ahmed and added a .pdf appendage and can read it (I've attached it for anyone else with the same issue). It's an Master of Science thesis from the University of Kufa, Iraq and I quote: 'Part one: Includes the preparation of titanium dioxide using sol-gel method by the reaction between titanium tetrachloride and ethanol with different mixing ratios (1:4, 3:10, 1:10), and under two different calcination temperatures (600, 800 °C)'. (my italics). There is no statement that any form of TiO2 is produced directly without a calcination process.
Yes, I agree, we must anneal the solution to remove extra chemicals. In the case, if you oven is not working, you can try hot-plate, sometimes even at 400 C you can get anatase phase TiO2 under atmospheric conditions.
In our experiment, our hot-plate can even go to higher temperature, see these attached papers:
1. Article Characterization and hydrogen gas sensing properties of TiO2...
2. Article Effect of Post-Deposition Annealing Treatment on the Structu...
Alan F Rawle Thanks a lot for sharing the knowledge. Its been a great help indeed.
You can get TiO2 nanoparticles (anatase) by hydrothermal synthesis. First, a sol-gel method is used to synthesize a TiO(OH)2 precursor, and then by heating precursor in an autoclave.you get nanocrystalline particles TiO2
Hydrothermal process is easiest. No calcining necessary. Can get 20 nm anatase in aqueous suspension, very stable. See attached and cited work therein.
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