Synthesis, characterization, and visible light photocatalytic activity of solution-processed free-standing 2D Bi₂O₂Se...

Owing to their unique structural and electronic properties such as layered structure with tuneable bandgap and high electron mobility, 2D materials have emerged as promising candidates for photocatalysis. Recently, bismuth oxyselenide (Bi₂O₂Se), a member of bismuth oxychalcogenide's family has shown great potential in high-speed field-effect transistors, infrared photodetectors, ferroelectric devices, and electrochemical sensors. However, the potential of Bi₂O₂Se in photocatalysis has not yet been explored. In the current work, Bi₂O₂Se nanosheets with an average size of ∼170 nm and a lattice strain of 0.01 were synthesized at room temperature using a facile solution-processed method and the as-synthesized material was investigated with various characterization techniques such as x-ray diffraction, FE-SEM, UV-vis spectroscopy. The bandgap for the indirect transition in Bi₂O₂Se nanosheets was estimated to be 1.19 eV. Further, the visible-light-driven photocatalytic degradation of methylene blue (MB) dye using Bi₂O₂Se as a photocatalyst is presented. The photocatalytic experiments demonstrate the promising photocatalytic ability of Bi₂O₂Se as it leads to 25.06% degradation of MB within 80 min of light illumination. The effect of active species trapping agents (carrier and radical scavengers) on photocatalytic activity is also presented and discussed.