Well, It depends on what you wish to know. In principle, running a complete isotherm, you can get specific surface area, pore size distribution, pore volume and even pore-type. I am attaching a very useful and highly cited article by Leofanti et. al, describing all this. I hope it will help you.

Well, It depends on what you wish to know. In principle, running a complete isotherm, you can get specific surface area, pore size distribution, pore volume and even pore-type. I am attaching a very useful and highly cited article by Leofanti et. al, describing all this. I hope it will help you.

If you can measure a full isotherm, please do it. For the B.E.T. area i suggest to take at least seven points (ten is better) located between 0.03 and 0.3 of relative pressure of N2. TiO2 is a mesoporous material, then the isotherm could be of type II with low surface area (no more than 20 cm^2/g). I suggest to see the articles of Rouquerol about N2 adsorption, including the book "Adsorption by powders and solids...".

if you use TiO2 as catalyst support, than you need to perform a full isotherm. Pore size distribution and pore volume are very useful.

But if you use TiO2 as active phase (photocatalysis for example): B.E.T can be enough.

It depends on your application.

BR,

I like to suggest you to do full isotherm. You have to concern about the following things:

1) Specific surface area(From BET method),

2) Pore size and pore volume( From BJH method)

3) Make a plot of (dv/dlogdp) vs dp. From this plot,you have to get some idea about that pore size distribution (micropore=less than 2nm, mesopore=between 2 to 50 nm,macropore=greater than 50 nm). Where dp is the pore diameter and V is the pore volume.