Preparation of amorphous Bi-Fe-O series semiconductor and its crystallization behavior and photocatalytic activity

Abstract

In that research field of Bi-Fe-O series compounds, the design and development of amorphous Bi-Fe-O semiconductor with high photocatalytic activity and pure phase BiFeO3 with multiferroic properties are two major challenges. Herein, the amorphous Bi-Fe-O series semiconductor is prepared by mechanical alloying method using Fe2O3 and Bi2O3 as the raw materials, and the pure phase nano-BiFeO3 crystalline is subsequently obtained by heat treatment process. Meanwhile the microstructure, band gap structure and photocatalytic or electromagnetic activity of amorphous and crystallized Bi-Fe-O semiconductor are also investigated. The results show that after 25 h of mechanical alloying, the crystalline structure of Bi2O3 and Fe2O3 is destroyed, and the system is transformed into amorphous phase. Moreover, photocatalytic hydrogen production experiment shows that amorphous Bi-Fe-O semiconductor has the highest photocatalytic hydrogen production rate which is 4.03 μmol/g/h, due to more defects and impurity energy levels. In addition, pure phase nano-BiFeO3 crystalline can be obtained when the heat treatment temperature of amorphous Bi-Fe-O semiconductor is 600°C, which have the best ferroelectric properties. This work not only provides new ideas for the research and development of amorphous semiconductor, but also proposes a green method to prepare pure phase nano-BiFeO3 crystalline.