The photodegradation of methylene blue (MB) was studied in aqueous solution over titania pillared ZrP and TiP under solar radiation. The reaction was studied by varying different parameters such as pH, titania load, catalyst concentration, initial MB concentration, irradiation time, effect of hydrogen peroxide (H2O2), effect of inorganic salts such as potassium persulphate (K2S2O8) and sodium chloride (NaCl). The initial rate of photodegradation of methylene blue is favoured in neutral pH (pH 7.0). Potassium persulphate and hydrogen peroxide were found to impose the enhancing effect on the rate of photodegradation of MB where as sodium chloride exhibits an inhibiting effect. (c) 2006 Elsevier B.V. All rights reserved.