Shape-controlled synthesis and facet-dependent performance of single-crystal Bi₂₅GaO₃₉photocatalysts

Abstract

Single-crystal Bi 25 GaO 39 cubes with exposed {100} facets and Bi 25 GaO 39 tetrahedra with exposed {111} and {112} facets were successfully synthesized through a facile hydrothermal route without using any template or organic surfactant for the first time. The formation process studies indicate that the amounts of NaOH and NaGaO 2 play an important role in the nucleation and growth rate of Bi 25 GaO 39 crystals. PL spectra and photoelectrochemical measurements indicate that the separation efficiency of photogenerated electronhole pairs in Bi 25 GaO 39 tetrahedra is higher than that in Bi 25 GaO 39 cubes. Moreover, Bi 25 GaO 39 tetrahedra exhibited superior photocatalytic activity in comparison with Bi 25 GaO 39 cubes for the degradation of AR1 and 4-NP pollutants, which may be primarily ascribed to the differences in exposed facets.

Facet‐Dependent Optical Properties of Semiconductor Nanocrystals

“…Ag 2 O cubes have the best photocatalytic activity, whereas rhombic dodecahedra have the lowest activity. In the literature, surface energy and molecular interactions with crystal surfaces through electrostatic considerations, as well as surface atomic arrangements and trap states/defects within a crystal, have been proposed to explain the observed facet‐dependent photocatalytic activities . The example of Cu 2 O and Ag 2 O having an identical crystal structure but exactly opposite photocatalytic behaviors demonstrates that these explanations are likely incorrect because they cannot be broadly applied.…”

Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

“…The catalytic properties encourage potential use of these compounds for photocatalytic applications in organic effluent treatment and water splitting. One such material, Bi 24 Ga 2 O 30 , plays the role of an efficient photocatalyst in degrading Methylene blue 8 . Few sillenite compounds also possess nonlinear optical (NLO) properties with a potential to be used further for second harmonic generation (SHG) applications.…”

Facet-Dependent Electrical, Photocatalytic, and Optical Properties of Semiconductor Crystals and Their Implications for Applications

“…35,45−47 For example, BiVO 4 square plates and truncated bipyramids have {010} basal faces and {110} lateral faces. 35 ZnO plates and rods have both end and side facets with significant proportion for each facet. 45 Anatase TiO 2 square plates have {001} basal faces and {101} lateral facets, and additional {010} side facets for tapered rectangular bars yielding tunable photocatalytic activity.…”

“…46,47 The imperfect control of crystal shapes and mixed facets makes the resulting photocatalytic differences less pronounced and harder to determine conclusively. 35 3.2. Facet-Dependent Photocatalytic Properties of Cu 2 O and Ag 2 O Crystals.…”