Enhanced photocatalytic activity in Al-substituted Bi2Fe4O9 submicrocrystals

Abstract

Bi 2 (Fe 1-x Al x ) 4 O 9 (x = 0, 0.1, 0.3, 0.5, and 0.7) samples were synthesized by a simple hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier transformed infrared spectra, N 2 -sorption, and UV-Vis diffuse reflectance spectra, and their photocatalytic activities were evaluated by the degradation of methyl orange under visible-light irradiation. The results reveal that the Al substitution can effectively improve photocatalytic performance, which is attributed to the increase of surface area, the improvement of energy band structure, and the distortion of the Fe-O octahedron in Al-substituted samples. In addition, it is found that the photocatalytic activity to decompose methyl orange under visible-light illumination increases monotonically as x increases from zero to 0.5 in Bi 2 (Fe 1-x Al x ) 4 O 9 and then decreases for x = 0.7, which is believed to be associated with the distribution of Fe 3? ions over the octahedral and tetrahedral sites.

Structural, Electrical, and Magnetic Properties of Mullite-Type Ceramic: Bi2Fe4O9

“…We have measured the active surface area using a Brunauer-Emmett-Teller (BET) measurement system at 77 K through nitrogen adsorptiondesorption isotherm method. The BET active surface area of Bi 2 Fe 4 O 9 is 1.2 m 2 /g, which is in good agreement with the values reported in the literature [27]. In order to obtain photocatalytic efficiency, it is necessary to increase the specific surface area by doping or reducing grain sizes.…”

Synthesis and Properties of Bi2Fe4O9 with FeCl2·6H2O Addition

“…High‐temperature structure studies established the behavior of inconsistent lattice expansion along a , b , and c ‐axis, which may indicate the polyhedron distortion varies with the temperature, and lead to the novel properties. The mid‐band gap (roughly 2.0 eV) and the special magnetism are believed to be responsible for the typical magnetoelectricity coupling and potential photocatalytic reactions effects in Bi 2 Fe 4 O 9 .…”

“…Properties of single‐phase Bi 2 Fe 4 O 9 is, of course, highly relevant for the subsequent cation‐doping effect studies to further improve the physics properties of Bi 2 Fe 4 O 9 . Single‐phase Bi 2 Fe 4 O 9 is, up to now, mostly synthesized by the hydrothermal method, which is complex and toxic.…”

Synthesis and Photocatalytic Activity of Bi₂Fe₄O₉ Using KOH as Mineralizer via Hydrothermal Method

“…In addition to its outstanding multiferroic property and gas sensitivity 6,7) , Bi 2 Fe 4 O 9 also exhibits a pronounced photocatalytic activity toward the degradation of organic dyes, phenol, and aqueous ammonia under visible light irradiation [8][9][10][11][12][13][14][15][16][17][18] . Moreover, the photocatalytic activity of Bi 2 Fe 4 O 9 can be improved by doping with metallic elements, ethylenediaminetetraacetic acid (EDTA) modi cation, and composite with graphene [19][20][21][22][23] . It is believed that the catalytic activity of photocatalyst is highly related to its structure, size, and morphology.…”