Photocatalytic activity and electrochemical impedance spectroscopy of TiO2 thermally treated by hydrogen

TiO2 treated in hydrogen atmosphere showed enhanced photocatalytic activity in degrading the sulfosalicylic acid (SSal),The results of the electrochemical impedance spectroscopy (EIS) investigation showed that the diameters of the capacitive arcs for the H-TiO2 were much smaller than those of bare TiO2 and thermally treated TiO2 in air, indicating that the charge transfer of the H-TiO2 occurs more rapidly, thus inviting a higher photocatalytic activity. when an external bias was applied on the H-TiO2, the arc of the EIS Nyquist plot decreased obviously than without the bias, suggesting more efficient separation of the photo-generated carriers