TiO2 foam is generally highly porous in nature, but for my sample it is showing very less around 600 micromoles for 2.5 hours. Can you give some suggestions about this comment?
I think that when you increase the surface area, you could also increase the electron-hole recombination probability. so, try to calculate the electron-hole recombination probability.
Take a look at this article: http://staff.ulsu.ru/moliver/ref/qc/elwa12.pdf
my suggestion to more control the reaction parameters to produce one phase as anatase with smaller particle size. At same time you can increase the percentage of rutile that phase helps more of recombination of electron which you can do by increase the calcintion temperature with control the ration of Tio2 source (starting material) .good luck