Controllable Synthesis of Bi2Fe4O9 Nanocrystal with High Active Facets and the Enhanced Visible Light Photoelectrochemical Property

Abstract

Bi2Fe4O9 nanocrystals with high active facets were controllably synthesized via a chemical co-precipitation process followed by a hydrothermal treatment at various microenvironment. The nanocrystals can be controlled preferentially to grow along (001) and show flat side facets of (110) and ($\bar 1$10). The photoinduced charge-transfer property of Bi2Fe4O9 was significantly improved. Such a high photo-to-current conversion efficiency is ascribed to the synergistic effect of energy band structure and the high reactivity of exposed (110) and ($\bar 1$10) facets. The high surface energy at the interface of the Bi2Fe4O9 efficiently reduced the recombination of photoinduced electron-hole pairs, and thus increasing the lifetime of charge carriers and enhancing the photo-to-current efficiency of the Bi2Fe4O9.