Shape-controlled synthesis and facet-dependent performance of single-crystal Bi25GaO39 photocatalysts

Abstract

Single-crystal Bi₂₅GaO₃₉ cubes with exposed {100} facets and Bi₂₅GaO₃₉ 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 NaGaO₂ play an important role in the nucleation and growth rate of Bi₂₅GaO₃₉ crystals. PL spectra and photoelectrochemical measurements indicate that the separation efficiency of photogenerated electron–hole pairs in Bi₂₅GaO₃₉ tetrahedra is higher than that in Bi₂₅GaO₃₉ cubes. Moreover, Bi₂₅GaO₃₉ tetrahedra exhibited superior photocatalytic activity in comparison with Bi₂₅GaO₃₉ cubes for the degradation of AR1 and 4-NP pollutants, which may be primarily ascribed to the differences in exposed facets.