Facile Fabrication of 3D-Ordered Macroporous Nanocrystalline Iron Oxide Films with Highly Efficient Visible Light Induced Photocatalytic Activity

Abstract

A facile approach of layer-by-layer depositing and hydrolysis of FeCl3 is developed to fabricate 3D-ordered Fe2O3 film. The 3D-ordered Fe2O3 film was characterized by SEM, XRD, and DRUV−vis. It has 3D-ordered interconnecting macropores (340 nm) with nanocrystalline hematite Fe2O3 walls (27.2 nm). The 3D-ordered macroporous nanocrystalline Fe2O3 film exhibits 2.4 times larger photocatalytic activity for the photodegradation of dye in the presence of H2O2 under visible irradiation than the nanocrystalline α-Fe2O3 film without macropores and very good photostability. The much higher photocatalytic activity of the 3D-ordered macroporous nanocrystalline Fe2O3 film than that of the reference Fe2O3 film is attributed to the unique nanostructure and architecture of the 3D-ordered Fe2O3 film, which result in the much greater light harvesting efficiency and efficient mass transport in the former than in the latter due to the existence of 3D-ordered interconnecting macropores. The effect of photonic stop band on the photocatalytic activity of the 3D-ordered Fe2O3 film was studied by angle-dependent solid-state photodegradation experiments with monochromatic irradiation. A slow photon enhancement of photocatalytic activity was achieved by adjusting the red edge of the photonic stop band of the 3D-ordered Fe2O3 film close to the electronic bandgap of Fe2O3. The photodegradation mechanism of crystal violet on the 3D-ordered Fe2O3 photocatalyst in the presence or absence of H2O2 was discussed.

Epitaxial Growth of Branched α‐Fe2O3/SnO2 Nano‐Heterostructures with Improved Lithium‐Ion Battery Performance

“…SnO 2 and α -Fe 2 O 3 , both important functional materials, have been intensively investigated separately for their applications as photocatalysts, [ 15 ] gas sensors, [ 16 ] and electrodes. [ 17 ] It has been previously demonstrated that a SnO 2 / α -Fe 2 O 3 hybrid composite can yield enhanced functions like gas sensitivity.…”

Ternary CdS/Au/3DOM-SrTiO 3 composites with synergistic enhancement for hydrogen production from visible-light photocatalytic water splitting

“…Especially, the red-edge of stop-band for inverse opals is thought to be more important in photocatalysis because of the relative higher refractive index of skeletal material. In the present work, because of the varied incident angle in the range of 0-90°, the stop-bands of these 3DOM-SrTiO3 materials were variable in a wide range [68,69] . It would result in a wide slow photon region at the red-edges of stop-band, and this slow photon region was partially overlapped with its stop-band.…”

Review of roles for photonic crystals in solar fuels photocatalysis

“…Broadband excitation should be avoided to allow one to discriminate between photogenerated carriers originating from slow photons and those originating from normal bandgap excitation. Under these controlled experimental conditions, one can quantify the level of photocatalytic enhancement attributed to the slow photon effect and utilize the ground rules established in the seminal work by Chen et al [20][21][22] and others 19,26 to engineer the stop band position for maximum photocatalytic activity.…”