In a short answer, yes.  I've done the same myself.  The usual (and main) reason for the use of propan-2-ol is that 100% ethanol  (and this is what you need) is taxed heavily in countries that think you may drink it.  IPA (propan-2-ol) is often considerably cheaper.  In either case the alcohol must be scrupulously dry - the azeotrope with water for ethanol is 4% water and I think 2.5% water for propan-2-ol  Both alcohols are hygroscopic and pick up moisture easily.  I think HCl gas is soluble in IPA and ethanol to a similar extent.

In a short answer, yes.  I've done the same myself.  The usual (and main) reason for the use of propan-2-ol is that 100% ethanol  (and this is what you need) is taxed heavily in countries that think you may drink it.  IPA (propan-2-ol) is often considerably cheaper.  In either case the alcohol must be scrupulously dry - the azeotrope with water for ethanol is 4% water and I think 2.5% water for propan-2-ol  Both alcohols are hygroscopic and pick up moisture easily.  I think HCl gas is soluble in IPA and ethanol to a similar extent.

Yes the role of ethanol and isopropanol is same. Ethano is the best solvent for titanium isopropoxide and tetra butyl titanate also.

Yes, it can be substituted. However, you should prepare the solution shortly before you perform your experiment. Otherwise, the titanium iso propoxide will exchange and partially become titanium ethoxide. The later has a different reaction rate and the resulting product will be "different".

As long as you perform all experiments in the same way (time-wise) there should not be any major problems. 

Thank you for all of your answers.

I've found method for synthesize N-doped TiO2 nanoparticle like this:

An adequate amount of Ti(OiPr)4 (0.1 M) was placed in isopropyl alcohol (100 mL) and the solution was agitated vigorously at 60 C for 30 min. Subsequently, 3.64 g of HDTMA was dissolved in distilled water (100 mL) to fix the generation of nitrogen and various silica sols (0, 0.1, 1, 10, and 100 mM) were added to the HDTMA solution and mixed for 30 min.

Can I do this procedure but replace isopropyl alcohol with ethanol? Is it true that HDTMA-Br can be used as nitrogen source doping?

i try it and when i drop ethanol to TTIP solution it became white 

@ Allouche  Are you using 100% ethanol?  The azeotrope is 96% EtOH and 4% water.  The latter will cause hydrolysis of the propoxide. You need to dry your EtOH over anhydrous sodium sulfate.  Distillation doesn't work for an azeotrope.

If the reaction is too quick, you can add some acetylacetonate (acac).

However, you need to be careful not adding too much. Otherwise it will not precipitate at all (or extremely slow).

Acac acts as a stabilizing agent (chelating agent).

yes i used ethanol with purity of 96% but i take care of 4% of water that existing in ethanol

but when i add ethanol 96% to TTIP solution slowly and dropwise the resultant solution is limpide

and i when i add ethanol 96% to TTIP fastly the milky solution is obtained

You need 100% ethanol. Period.

The same results are obtained when I use Ethanol at 99.8% of purity

The milky solution is always obtained 

But I THINK THAT the TTIP solution is influenced by moisture

Yes, pretty much all alkoxides are VERY sensitive to moisture. The only exception  to that rule is TEOS, which you can actually mix with water and no apparent reaction occurs (unless acid or base is added).

For that reason all reactions with alkoxides should be closely controlled with regard to water exposure.  

@Mr Herbert 

What do you mean TEOS

when I mix water with TTIP that I have the aggregate appears very rapidly 

Is that mean that MY TTIP IS OBSOLETE 

THANKS VERY MUCH

Thanks

TEOS is generally taken to mean tetraethylorthosilicate.  With your ispropoxide (TTIP) then reaction with water is instant as you have found out.  Your TTIP is not obsolete - it's reacting as expected.  That's why moisture exclusion is so important until it's needed.

There other phenomenon is observed when I add ethanol (96% or 99.8%) the milky solution is obtained and when adding HCl 37% to this mixture the limpid solution is obtained spontaneously 

I am prepared TiO2 thin film by sol-Gel , and using TTIP , 1N HCl and isopropanol to make 0.5 M and 1M .

But after stirring for 24 hr at 500 rpm and room temperature , the 0.5 M has freezing !!!! What is the reason ??!!!