Efficient photodegradation of Eosin B dye by practical application of Phosphorous doped Titanium dioxide photocatalyst based on green chemistry principles. Phosphorous doped Titanium dioxide photocatalyst was synthesized using Titanium dioxide powder and Ortho-Phosphoric acid in calculated quantities in the ratio of 1:1. The photodegradation of the Eosin B dye was performed with the prepared photocatalyst with various concentrations and with different parameters. The photocatalysts were characterized by IR, SEM, EDAX, XRD, UV-VIS spectroscopic methods. The activity of the photocatalyst was analyzed on the pollutant and degradation was performed under irradiation. Increment of Eosin B dye degradation has been revealed in this work.