Synthesis, photoelectric properties and photocatalytic activity of the Fe2O3/TiO2 heterogeneous photocatalysts.
Fe(2)O(3)/TiO(2) heterogeneous photocatalysts with different mass ratios of Fe(2)O(3)vs. TiO(2) were synthesized by impregnation of Fe(3+) on the surface of TiO(2) microrods and calcination at 300 degrees C. Scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), photoluminescence spectra and X-ray diffraction (XRD) have been used to characterize the samples. The photocatalytic activities of Fe(2)O(3)/TiO(2) heterocomposites, pure Fe(2)O(3) and pure TiO(2) were evaluated by the photodegrading efficiency of Orange II under visible light (lambda > 420 nm). The experiments demonstrated that Orange II in aqueous solution was more efficiently photodegraded using Fe(2)O(3)/TiO(2) heterogeneous photocatalysts than either pure Fe(2)O(3) or TiO(2) under visible light irradiation. With an optimal mass ratio of 7:3 in Fe(2)O(3)/TiO(2) the highest rate of Orange II photodegradation was achieved under the experimental conditions. We have also compared the photoelectric properties of Fe(2)O(3)/TiO(2) heterogeneous photocatalysts with that of pure Fe(2)O(3) by surface photovoltage (SPV) and transient photovoltage (TPV) techniques. Based on the photovoltage responses, we discussed the influence of the hetero-interface between Fe(2)O(3) and TiO(2) on transfer characteristics of photogenerated charge carriers. We demonstrated that the formation of heterojunctions between Fe(2)O(3) and TiO(2) for Fe(2)O(3)/TiO(2) composites was pivotal for improving the separation and thus restraining the recombination of photogenerated electrons and holes, which accounts for the enhancement of photocatalytic activity.
College of chemistry, Jinlin University, Changchun 130012, PR China.
Linlin
L
Peng
Tengfeng
T
Xie
Yongchun
Y
Lu
Haimei
H
Fan
Dejun
D
Wang