Photodegradation of BiNbO₄ Powder during Photocatalytic Reactions

Abstract

BiNbO 4 powders prepared by solid state reaction were tested for photocatalytic activity in methanol solutions under UV irradiation. When the material is tested without the presence of a Pt cocatalyst, photocatalytic activity for H 2 evolution is superior to that of TiO 2 . It was also found that BiNbO 4 photodegrades into metallic Bi and reduced Nb oxides after use; materials were characterized by SEM, XRD, and XPS. Adding Pt to the surface of the photocatalyst increases photocatalytic activity and importantly, helps to prevent photodegradation of the oxide material. With 1 wt % Pt loading, photodegradation is essentially absent.

Temperature stability and electrical properties of MnO‐doped KNN‐based ceramics sintered in reducing atmosphere

“…The Bi 4f 7/2 peak (159.00 eV) of Mn0 ceramic is slightly higher than that (158.90 eV) of Mn0‐air ceramics, which is similar to the behavior of Nb 3d 5/2 peak, because of the higher oxygen vacancy concentration . The binding energy of the used BiNbO4 catalysts show a 0.2 eV lower shift, corresponding to a reduction in the Bi in the catalyst . Therefore, we consider that a reduction in the Bi could occur in Mn0 ceramics.…”

Synthesis of by the Flux Method

“…Among candidate photocatalysts, BiNbO 4 seems especially promising for the following reasons: (1) it exhibits higher photocatalytic activity for H 2 evolution than TiO 2 [6], (2) it undergoes a phase transition from low-temperature orthorhombic to high-temperature triclinic at 1293 K [7][8][9], and (3) its low-temperature phase exhibits higher photocatalytic activity than its high-temperature phase [10][11][12][13][14].…”

Mo- and N-doped BiNbO4 for photocatalysis applications

“…7 It has been studied for the hydrogen production via photocatalytic process in methanol solutions under UV irradiation in the presence of co-catalyst Pt. 8 The experimental band gap of the BiNbO 4 is around 2.6 eV, 7 which is larger than the required band gap (2.0 eV) for the maximum utilization of visible light spectrum. Band gap engineering is required to improve the efficiency of photocatalytic material by anion, cation, or co-doping, thus induces donor or acceptor states which are very close to the band edges.…”