Enhanced visible light photocatalytic activity of Fe(2)O(3) modified TiO(2) 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.