One-step synthesis, electronic structure, and photocatalytic activity of earth-abundant visible-light-driven FeAl₂O₄

Abstract

The development of inexpensive visible-light-driven photocatalysts is an important prerequisite for realizing the industrial application of photocatalysis technology. In this paper, an earth-abundant FeAlO photocatalyst is prepared via facile solution combustion synthesis. Density functional theory and the scanning Kelvin probe technique are employed to ascertain the positions of the energy bands and the Fermi level. Phenol is taken as a model pollutant to evaluate the photocatalytic activity of FeAlO. The scavenger experiment results, ˙OH-trapping fluorescence technique, and electron spin resonance measurements confirm that the superoxide anion radical is the main active species generated in the photocatalytic process, which also further corroborates the proposed electronic structure of FeAlO. The degradation experiments and O temperature programmed desorption results over various samples verify that the crystallinity degree is a more important factor than the oxygen adsorption ability in determining photocatalytic activity.

Solution Combustion Synthesis of Complex Oxide Semiconductors

“…However, increasing F/O to 2.0 produced a well-crystallized material [49]. A similar trend was also found for the combustion synthesis of FeAl 2 O 4 and MgAl 2 O 4 [24][25][26]. For the synthesis of FeAl 2 O 4 , different molar ratios of urea (3 to 7) were used; excess urea reduced the surface area and increased the particle size.…”

Metallic conduction and ferromagnetism in MAl2O4/SrTiO3 spinel/perovskite heterostructures (M = Fe, Co, Ni)

“…On the one hand, the Febased oxide has poor ability to reduce STO substrate during the film deposition. 23 On the other hand, the band gap of FeAl2O4 (1.78 eV 24 ) is much lower than that of STO (3.2 eV), any reconstructed electrons tend to accumulate in the spinel films rather than transferring to the heterointerface. heterointerfaces, magnetic measurements were performed by superconducting quantum interference device (SQUID) magnetometer (as shown in Fig.…”

Photocatalytic performance of Fe‐substituted ZnAl2O4 powders under sunlight irradiation on degradation of industrial dyes

“…In a semiconductor, the lowest occupied and the highest unoccupied energy bands are separated by a bandgap ( E g ) 72 . The E g specifies the light wavelength for photocatalyst materials, which may be absorbed quickly to generate electron‐hole pairs with the ability to react with water molecules, oxygen molecules, and hydroxide ions in order to generate hydroxyl radicals () and superoxide radical anions () 73‐75 . Equations ()–() describe this process, as shown in Figure 11.…”

“…72 The E g specifies the light wavelength for photocatalyst materials, which may be absorbed quickly to generate electron-hole pairs with the ability to react with water molecules, oxygen molecules, and hydroxide ions in order to generate hydroxyl radicals (OH ⋅ ) and superoxide radical anions (O ⋅ − 2 ). [73][74][75] Equations ( 14)-( 17) describe this process, as shown in Figure 11. When solar energy (photons) that irradiated on the surface of semiconductor photocatalysts carries a photon energy greater than or equal to their E g , the electrons in the valence band (VB) are stimulated and reach their conduction band (CB) in femtoseconds, leaving behind the holes in the valence band.…”