Synthesis of Bi2Fe4O9/reduced graphene oxide composite by one-step hydrothermal method and its high photocatalytic performance

Abstract

Visible-light-driven degraded organic pollutant with high efficiency is crucial in the current photocatalysis research. A new kind composite photocatalyst with high visible-light photocatalytic activity which consists of Bi2Fe4O9 and reduced graphene oxide (RGO) has been synthesized through one-step hydrothermal method at low temperature. Pure Bi2Fe4O9 was formed with the addition of graphene oxide (GO) when the concentration of NaOH is 12 mol/L (M) at 180 °C for 72 h hydrothermal reaction. At the same time, the GO was reduced to RGO and adsorbed on the surface of Bi2Fe4O9. The resultant composite photocatalyst showed higher absorption not only in the UV range but also in the visible light than pure Bi2Fe4O9 indicating more electron–hole pairs generated. The band gap of photocatalysis was reduced from 1.91 to 1.69 eV and recombination of photo-generated electron–hole pairs in composites were decreased through marrying RGO with Bi2Fe4O9. As a result, the Bi2Fe4O9/RGO composite photocatalyst displayed higher catalytic activity for the degradation of methyl violet under visible light irradiation than rare Bi2Fe4O9, promising the use of the Bi2Fe4O9/RGO composite in visible-light photocatalysis.