Polyimide/Ag 2 WO 4 Z-Scheme Heterojunction for Efficient Photocatalytic Degradation of Tetracycline

It is of great significance to construct a Z-scheme heterojunction for improving solar light harvesting and achieving efficient separation of photogenerated carriers and then enhancement of the photocatalytic performance of semiconductor photocatalysts. Herein, the direct Z-scheme PI/Ag WO heterojunction was designed and prepared according to the band edge potentials of the semiconductor. Due to the fact that the Z-scheme structure not only endowed the PI/Ag WO composites with efficient separation of photogenerated electron-hole pairs but also reserved the redox ability of the valence band and conduction band of monophase catalysts, the 50% PI/Ag WO heterojunction exhibited excellent photocatalytic activity, which were 2.9 and 1.5 times those of the PI and Ag WO photocatalysts, respectively. The photocatalytic reaction mechanism of PI/Ag WO composites was confirmed by the results of TEM, UV-vis, XPS, and EPR experiments. This work provides a feasible strategy to design high-performance photocatalysts in the field of practice purification of wastewater.