Enhanced visible light photocatalytic activity of Fe2O3 modified TiO2 prepared by atomic layer deposition

In this work, commercial anatase TiO 2 powders were modified using ultrathin Fe 2 O 3 layer by atomic layer deposition (ALD). The ultrathin Fe 2 O 3 coating having small bandgap of 2.20 eV can increase the visible light absorption of TiO 2 supports, at the meantime, Fe 2 O 3 /TiO 2 heterojunction can effectively improve the lifetime of photogenerated electron–hole pairs. Results of ALD Fe 2 O 3 modified TiO 2 catalyst, therefore, showed great visible light driven catalytic degradation of methyl orange compared to pristine TiO 2 . A 400 cycles of ALD Fe 2 O 3 (~ 2.6 nm) coated TiO 2 powders exhibit the highest degradation efficiency of 97.4% in 90 min, much higher than pristine TiO 2 powders of only 12.5%. Moreover, an ultrathin ALD Al 2 O 3 (~ 2 nm) was able to improve the stability of Fe 2 O 3 -TiO 2 catalyst. These results demonstrate that ALD surface modification with ultrathin coating is an extremely powerful route for the applications in constructing efficient and stable photocatalysts.