Fabrication of novel Ag4Bi2O5-x towards excellent photocatalytic oxidation of gaseous toluene under visible light irradiation.

Abstract In this work, a novel oxide combined with bismuth (Bi) and silver (Ag) was prepared via simple ball milling. This substance was optimized by adjusting the amount of pre-source. Preliminary characterization results confirmed the successful synthesis of Ag4Bi2O5. Subsequently, gaseous toluene was selected as model compound to evaluate the photocatalytic activity of Ag4Bi2O5 photocatalyst. According to the degradation results, Ag4Bi2O5 performed excellent visible light-driven photocatalytic activity with high stability. For the oxidation process of gaseous compound, reactive oxygen species (ROS) were responsible for the achievement, and the formation of oxygen vacancies on Ag4Bi2O5 were involved in the generation of ROS to promote the transfer of photogenerated electrons, and improving photocatalytic activity. DFT calculations revealed the theoretical band gap of Ag4Bi2O5 bulk is 1.758 eV. And the work function of Ag4Bi2O5 (112)ov was ca. at 4.447 eV. The material was easily fabricated and a reliable path was provided for the synthesis of new and efficient photocatalyst for the remediation of polluted indoor air.