Enhancement of visible light photocatalytic performances of Bi2MoS2O4 nanoplates

Abstract

A novel Bi₂MoS₂O₄ nanoplate photocatalyst with high-energy efficiency and high-activity has been successfully synthesized by a reflux method. The visible-light response of Bi₂MoS₂O₄ could extend from 480 to 630 nm compared with Bi₂MoO₆. Compared with Bi₂MoO₆, the photocatalytic activities of the Bi₂MoS₂O₄ sample increased about 0.4 and 4.6 times for degradation of methylene blue (MB) under UV and visible-light (λ > 510 nm) irradiation, respectively. Density functional calculations revealed that Bi₂MoS₂O₄ had a narrower band gap and wider valence bandwidth compared with Bi₂MoO₆ because S 3p orbitals contributed to the valence band formation. The high energy efficiency of Bi₂MoS₂O₄ photocatalysts came from a narrow bandgap and the high activity came from a wider and dislocated valence band of Bi₂MoS₂O₄. Furthermore, the synthesis of Bi₂MoS₂O₄ could afford guidance for designing the other high-energy efficient and highly active photocatalysts.