Enhanced photocatalytic hydrogen production and degradation of organic pollutants from Fe (III) doped TiO2 nanoparticles

In the present work, bare TiO2 and different molar concentrations of iron (Fe3+)-doped TiO2 photocatalysts (0.05-1 mol % Fe) were prepared by a simple precipitation method for photocatalytic hydrogen production and degradation of organic pollutants (MO and 4-CP) under light irradiation of lambda >= 320 nm. XRD revealed the presence of anatase phase for both bare TiO2 and Fe doped titania. Based on the XPS results, Fe3+ ions are hardly seen may be attributed to the location of iron inside the titania matrix rather than their appearance at the surface. UV-vis-DRS of the doped titania demonstrated a redshift toward visible region owing to the reduced bandgap energy. N-2 adsorption results showed that the doped materials have higher surface area compared to bare TiO2 due to decrease particle size. Importantly, electrochemical experiments (electrochemical impedance spectroscopy (EIS), photocurrent (PC), and photoluminescence (PL)) revealed that higher photogenerated charge carrier separation efficiency of iron-doped titania. Results showed that the 0.1 mol % Fe doped TiO2 exhibited the highest photocatalytic activity for both degradation and H-2 evolution reactions. Furthermore, high surface area, small particle size and enhanced visible-light absorption as well as improved charge transfer and separation are believed to be responsible for the improvement of photocatalytic activity of the doped materials.