I prepared TiO2 by sol-gel method by dissolving 0.025M Titanium Butoxide and Triethanolamine in ethanol followed by adding 0.05M water in 10mL water. The solution was yellow and as I heated the solution at 50C with constant stirring, a gel formed. As I heated the gel at 500C for 1 hours in a muffled furnace with constant N2 gas flow, I obtained a black material with translucent shiny appearance.
Is this black titania? What analysis should I do to confirm?
Dear Aquib Mohammed Ayman, similar questions have been already discussed within RG. Pleased check the following links. My Regards
https://www.researchgate.net/post/what_are_the_white_TiO2_blue_TiO2_and_black_TiO2_Are_these_differentiate_on_the_basis_of_color_only
https://www.researchgate.net/post/Can_anyone_explain_why_titania_white_color_changes_to_blue_grey_or_black2
https://doi.org/10.1155/2017/8529851
https://doi.org/10.1039/C4CS00330F
https://www.acsmaterial.com/blog-detail/black-titanium-dioxide.html
Dear Aquib Mohammed Ayman, similar questions have been already discussed within RG. Pleased check the following links. My Regards
https://www.researchgate.net/post/what_are_the_white_TiO2_blue_TiO2_and_black_TiO2_Are_these_differentiate_on_the_basis_of_color_only
https://www.researchgate.net/post/Can_anyone_explain_why_titania_white_color_changes_to_blue_grey_or_black2
https://doi.org/10.1155/2017/8529851
https://doi.org/10.1039/C4CS00330F
https://www.acsmaterial.com/blog-detail/black-titanium-dioxide.html
Aquib Mohammed Ayman
An extremely important role in the sol-gel process is played by the processes of removing the solvent from the gel (drying). As you did, you did not write. The solution with the gel had to be dried under vacuum to obtain a xerogel without water, and then gradually heated in order to convert the xerogel in the form of titanium hydroxides into titanium dioxide. You did not perform this operation correctly, and therefore charcoal appeared during sintering, which colored your product black.
Dear Abdelkader Bouaziz, thank you for your links.
Dear Yuri Mirgorod,
You are correct. I evaporated the solvent on top of a hot plate under constant stirring at 50C. The temperature did not go above 50C. However, as the volume became very low, I removed the magnetic stirrer and let the gel cool down. The gel was transferred to glass boats before they solidified, then it was allowed to become gel. I heated it rather quickly, at 5C/min to 500C, while the temperature was set to 250C and 400C for 10 minutes.
So you are right, I did not perform this operation correctly. Thanks for your input.
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