A set of transition metal doped nanosized TiO2 particles with anatase structure were synthesized by the pulverization method and their ability to photocatalytically degrade the dye Alizarin Red S was investigated. Characterization of the Zr-, Co- and Mo-doped photocatalysts was conducted with the aid of XRD, SEM, EDX, TEM, BET and spectral analysis. X-ray diffraction patterns did not reflect the appearance of any peaks due to dopants, however dopants were observed in SEM-EDX analysis. Particle sizes were in the range of 25 nm as per TEM and XRD analysis. Upon doping, a prominent decrease in surface area was observed. The percentage composition of each of the dopants was confirmed by EDX analysis. Doped samples depicted many mid-bands in the Kubelka Munk plots due to d-d transition of dopants. Experiments were conducted to compare the photocatalytic activity under identical UV and solar light exposure. Zr-doped TiO2 at the molecular scale exhibited better photocatalytic activity in degradation of Alizarin, with a lower band-gap energy that can respond to visible light. However, Co- and Mo-doped TiO2 appeared to suppress the photoactivity. A rise in the number of mid-bands causing effective separation or recombination of charge carriers strongly influences the rate of the degradation process. <alternatives> [...] </alternatives>
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