Mechanism of enhanced photocatalysis of TiO2 by Fe3+ in suspensions

► The degradation of SD can be promoted by the addition of Fe3+ in TiO2 suspension, and Fe2+ is found not to give an obvious impact on the SD degradation. ► The hydroxyl radical generated by TiO2/Fe3+ photocatalysis is in a higher yield, and adsorption amount of TiO2 is greatly enhanced by the addition of Fe3+ in suspensions. ► The enhancement of photocatalytic activity of TiO2 by Fe3+ can be attributed to the fact, which is both oxygen and Fe3+ as the electron acceptors to trap the electron in the conduction band of TiO2.