Controllable Synthesis, Magnetic Properties, and Enhanced Photocatalytic Activity of Spindlelike Mesoporous α-Fe₂O₃/ZnO Core–Shell Heterostructures

Abstract

Mesoporous spindlelike iron oxide/ZnO core-shell heterostructures are successfully fabricated by a low-cost, surfactant-free, and environmentally friendly seed-mediate strategy with the help of postannealing treatment. The material composition and stoichiometry, as well as these magnetic and optical properties, have been examined and verified by means of high-resolution transmission electron microscopy and X-ray diffraction, the thickness of ZnO layer can be simply tailored by the concentration of zinc precursor. Considering that both α-Fe2O3 and ZnO are good photocatalytic materials, we have investigated the photodegradation performances of the core-shell heterostructures using organic dyes Rhodamin B (RhB). It is interesting to find that the as-obtained iron oxides/ZnO core-shell heterostructures exhibited enhanced visible light or UV photocatalytic abilities, remarkably superior to the as-used α-Fe2O3 seeds and commercial TiO2 products (P25), mainly owing to the synergistic effect between the narrow and wide bandgap semiconductors and effective electron-hole separation at the interfaces of iron oxides/ZnO.

Advances in Magnetically Separable Photocatalysts: Smart, Recyclable Materials for Water Pollution Mitigation

“…Other haematite-based magnetically separable nanostructured photocatalysts such as graphene (GR)-α-Fe 2 O 3 -ZnO [93], α-Fe 2 O 3 /TiO 2 nanofibres [94], α-Fe 2 O 3 /RGO [95], and α-Fe 2 O 3 /ZnO [96] have been fabricated, have shown remarkable visible light utilisation, and have been easily separable using an external magnetic field. Coupling the various semiconductors with α-Fe 2 O 3 resulted in synergy between the materials, leading to enhanced visible light response, improved charge separation, and an overall increase in photocatalytic activity.…”

Development of novel α-Fe2O3/NiTiO3 heterojunction nanofibers material with enhanced visible-light photocatalytic performance

“…After the reaction time of 180 min, the decomposition of RhB was observed to be 90.4% employing a-Fe 2 O 3 /NiTiO 3 composites, while it was only up to 55.1% and 59.0% for Fe 2 O 3 nanofibers and NiTiO 3 nanoparticles, respectively. As the photodegradation reaction process with a low-concentration of RhB solution, followed a pseudo-firstorder reaction [28], the apparent rate constant value K of the decomposition could be calculated to be 0.0135 min À1 for a-Fe 2 O 3 /NiTiO 3 composites (Fig. 4d), which was higher than that of pure Fe 2 O 3 nanofibers (the K value was 0.0044 min À1 ) and NiTiO 3 photocatalysts (the K value was 0.0050 min À1 ).…”

Ag/ZnO/graphene oxide heterostructure for the removal of rhodamine B by the synergistic adsorption–degradation effects

“…Thus the development of well-defined ZnO-based heterostructures with narrowed band gap, excellent light absorption and highly efficient dye adsorption has been actively pursued [13][14][15][16][17][18][19][20][21].…”