Borophene-based mixed-dimensional van der waals heterojunctions for high-performance self-powered photodetector

Borophene-based mixed-dimensional van der Waals heterojunction is prepared and utilized for self-powered photoelectrochemical (PEC)-type photodetector. • Mixed-dimensional van der Waals 2D B@ 0D Bi heterojunction is designed. • B@Bi-based PEC-type photodetector exhibits self-powered photodetection capability. • The photodetector exhibits fast response and recovery speed. The ongoing pursuit of mixed-dimensional van der Waals heterojunctions has attracted enormous interests owing to their obviously enhanced photoelectrochemical (PEC) characteristics compared to their single components. Herein, we demonstrate the preparation of 0D Bismuth nanoparticles (Bi NPs) coated 2D Borophene (B@Bi) mixed-dimensional heterojunction by hydrothermal method. Benefiting from the promoted photo-induced electron/hole pair separation, shorted charge transfer length, and built-in electric field, the fabricated B@Bi-based PEC-type photodetector (PD) exhibits enhanced self-powered photodetection properties along with the fast response and recovery speed (0.02/0.02 s) in 0.5 M KOH electrolyte under 365 nm illumination. Additionally, repeatable ON/OFF switch signals can be observed after 30 days. Our present work provides an opportunity for fabricating high-performance mixed-dimensional B@Bi-based PDs with good long-term stability.