Polyimide/Ag₂WO₄ Z-Scheme Heterojunction for Efficient Photocatalytic Degradation of Tetracycline

Abstract

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 2 WO 4 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 2 WO 4 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 2 WO 4 heterojunction exhibited excellent photocatalytic activity, which were 2.9 and 1.5 times those of the PI and Ag 2 WO 4 photocatalysts, respectively. The photocatalytic reaction mechanism of PI/Ag 2 WO 4 composites was confirmed by the results of TEM, UV−vis, XPS, and EPR experiments. This work provides a feasible strategy to design highperformance photocatalysts in the field of practice purification of wastewater.

Synthesis and Photocatalytic Application of Magnetic CoFe2O4/Conjugated Poly(vinyl chloride) Derivative Nanocomposite

“…A lot of research demonstrates that coupling with conjugated polymers (CPs) can substantially heighten the photocatalytic activity of semiconductors. − Generally, CPs can increase the photocatalysis of semiconductors due to the following positive cooperative effects: (i) they can be activated by visible-light to provide additional h + and e – , due to their exceptionally strong absorption of visible-light, and (ii) they can promote the separation and transfer of h + and e – , due to their capability of forming heterojunctions with semiconductors and fair charge-transporting ability. − But, most CPs explored in the past are difficult to mass produce and are not cost-effective polythiophene, polyimide, polyaniline, polypyrrole, etc., which are unsuitable for large-scale industrial applications. − …”