The effect of transition metal ions such as Mo (VI) doped ZnO has been investigated for
photocatalytic bleaching of eosin Y. Doped samples were synthesized by stirring and microwave
exposure. The effect of concentration of dopant on the rate of photocatalytic bleaching of dye has
also been observed. The rate of photocatalytic bleaching of dye increases with increase in
concentration of dopant up to a certain limit with all these metal ions, but decreases after further
concentration of dopants. A tentative mechanism has been proposed.