Everything is a chemical.... Water is a chemical.....  I assume you're not a chemist, Ashna?

@ Khaled Metals don't dissolve in water unless they react and then they're no longer metals...e.g. sodium.  Al has an oxide film on it and does not react with water unless in the form of an amalgam where it reacts well.  Mg dissolves slowly as it (slowly) reacts to form the hydroxide.

Dear Ashna

The element of Titanium (Ti) is well known to have an inherent oxide film.   So, the Ti oxide film could be  an excellent counter (auxiliary) electrode in a  three electrodes electrochemical cell(system).   Ti has high exchange current.   In other words, the reversible reaction of ; Ti  to Tin + ne is very fast in which the cathodic exchange current (ic) and the anodic exchange current (ia) are not only so fast but also they are equal.   Therefore,  the net exchange current; ic-ia=0, This implies that  the Ti doesn't polarize or dissolve in water.  

As far as I know, Ti is a passive metal, resistant even in most of the acids. This justifies its use in corrosion-protecting coatings.

Everything is a chemical.... Water is a chemical.....  I assume you're not a chemist, Ashna?

@ Khaled Metals don't dissolve in water unless they react and then they're no longer metals...e.g. sodium.  Al has an oxide film on it and does not react with water unless in the form of an amalgam where it reacts well.  Mg dissolves slowly as it (slowly) reacts to form the hydroxide.

Dear Alan

The question wasn't clear, So If Ashna's question was " ......Ti in aqueous solution without using chemicals", meant in water, the TiO2 wouldn't dissolve in water because of the reasons that I had mentioned earlier. 

Dear Ashna

According to Davilliers et al., The metal is covered by a stable oxide film of TiO2 when the metal is exposed to air or anodised. Its corrosion resistance is excellent in many media, but its corrosion rate may be significant in concentrated acid solutions. For example, the protecting oxide film is dissolved gradually in concentrated sulfuric acid.

It is not always possible to evidence the dissolution of TiO2 from usual electrochemical methods (polarisation resistance determination; impedance measurements) because that reaction is counter-balanced by the passivation of the

electrode (formation of a TiO2 layer). When the dissolution rate is greater than the formation rate in sulphuric acid, some parts of the electrode are naked. This situation is easy to detect by different techniques:

1. from the OCP curves: sharp decrease of the potential, leading to very negative values.

2. from impedance diagrams: decrease of the real part of impedance, especially in the high frequency loop.

3. from the measurement of the polarisation resistance Rp: its value is very small when the electrode is no more covered by a TiO2 layer.

by

Thanks to everyone for answering my question.

Alen Sir i'm not chemist. I'm biotechnologist and just enrolled for PhD.

I want to dissolve Ti in water without using sulphuric acid for biosynthesis of Ti nanopartice.

Dear Ashna 

Take a look at the following:

https://www.researchgate.net/post/How_can_I_completely_dissolve_ZnO_and_TiO2_Nanoparticles

on possibilities of how TiO2 nanoparticles can be dissolved/suspended in water.

Good luck.

Interesting, the real issue is that in order to dissolve Ti in water, it must form ions, but Ti ions spontaneously hydrolyze with water at neutral pHs to form oxides or hydroxides that precipitate from the solution. They will also form on the surface of the metal causing it to passivate, as discussed above. So, you need some way to stabilize the Ti ions in the aqueous solution. One way is to lower the pH (such as with sulfuric acid), another would be to find a chelating agent that will form complexes with the Ti ions that will not interfere with your synthesis. I would make a suggestion, but this is not my field.

Dear Ashna,

Why do you need to dissolve Ti?

Dear Ashna

I have some questions :

- do you really need pure Ti nanoparticles ?

- could it be TiO ? Or a Ti alloy ?

- How big and how many of such particles do you need ?

- Did you consider the possibility to buy the powder ?

There are a lot of processes for the production of Ti powders. Did you do some preliminary research on this ?

Hello,

One approach is through electrolysis. This method is known when it is necessary to process titanium for making a tool. It may partially enter the aqueous solution by foamy or bulk erosion.

With respect

Emil Yankov

Respected Ahmad Mostafa Sir,

I am trying to make Ti nanoparticles by green approach (using plant extract as reducing agent) as well cost effective, less toxic.

Alberto Cerri Sir,

It could be form of oxides but not alloy. here i use Ti salt use as precursor and i need NPs as small as possible.

Is this helpful ?

http://www.sigmaaldrich.com/materials-science/material-science-products.html?TablePage=19922558