Visible-light decomposition of gaseous toluene over BiFeO3–(Bi/Fe)2O3 heterojunctions with enhanced performance

Abstract

The comprising of multicomponent heterojunctions is an effective strategy to design a highly active photocatalyst. However, the trade-off between the extension of light responsive region and suppress of charges recombination is still its major obstacle. Herein, BiFeO3–(Bi/Fe)2O3 heterojunctions composed by two small band gap components, are synthesized via a facile one-pot hydrothermal process. The parasitic phase of (Bi/Fe)2O3 in BiFeO3 synchronously makes its a clearly red shift of light absorption edge up to approximately 665nm, enhanced visible-light absorption, and improved charge separation due to their suitable bands positions and intimate contact. In the application of photocatalytic destruction of gaseous toluene, toluene can be deeply oxidized into CO2 over BiFeO3–(Bi/Fe)2O3 under visible light irradiation (λ>400nm) and ambient temperature. In comparison with BiFeO3, BiFeO3–(Bi/Fe)2O3 exhibits 2.5times higher activity under parallel test conditions and outstanding cyclic performance. Such BiFeO3–(Bi/Fe)2O3 heterojunction and its composing strategy may bring new insight into the designing of highly efficient photocatalysts and potential technological applications.