High temperature stable nanocrystalline anatase TiO2 is well known for its aqueous mediated non-selective photocatalysis. Here we first report the selective solar photocatalysis of high temperature stable anatase TiO2, prepared through a modified sol-gel technique using titanium isopropoxide and ammonium fluoride. As synthesised samples calcined at 500 and 700 degrees C were characterized by various techniques such as XRD, FTIR, TEM, diffuse reflectance spectroscopy, BET surface area analyser and XPS. TiO2 samples calcined at 500 and 700 degrees C (TNF500 & TNF700) selectively degraded cationic methylene blue (MB) over anionic methyl orange (MO) from an aqueous mixture of MB and MO dye. The selective photocatalysis was well accounted by zeta potential measurements.