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.

Keywords: Ag(4)Bi(2)O(5); Gaseous toluene; Oxygen vacancy; Photocatalytic.