Composition-driven control of charge dynamics in visible-light-responsive sheet-like photoelectrodes

Abstract

In this study, we prepared sheet-like porous Bi2O3 using a chemical bath method. Subsequently, the conductive polymer polyaniline (PANI) was deposited onto its surface through spin coating, followed by the uniform growth of silver particles via a photoreduction method, successfully creating a Bi2O3/PANI/Ag heterostructure. The it-conjugated conductive structure of PANI forms a p-n heterojunction with Bi2O3, establishing an internal electric field at the interface. This configuration effectively suppresses electron-hole recombination and promotes the directional separation of carriers. Furthermore, incorporating silver particles improves interfacial chargetransfer efficiency and suppresses carrier recombination. This heterostructure demonstrates a Type-II band alignment, which is beneficial for carrier migration. By optimizing the concentrations of PANI and Ag, we can enhance light absorption capability, interfacial conductivity, and carrier lifetime simultaneously, resulting in a significant improvement in photoelectrochemical efficiency. This study highlights that interfacial engineering, combining PANI and Ag, can mitigate the intrinsic limitations of Bi2O3, such as charge recombination and low conductivity, offering a promising approach for developing more efficient photoelectrode materials.