Porous Single-Crystalline CdSe Nanobelts: Cation-Exchange Synthesis and Highly Selective Photoelectric Sensing toward...

Porous single-crystalline nanostructures are of tremendous interest for their application in the catalytic, electronic and sensing fields due to their large active surfaces, favorable diffusion, and good electronic transport. Despite the recent advances of various other components, photoelectric chalcogenides remain almost undeveloped. The present study contributes a facile strategy to prepare porous single-crystalline CdSe nanobelts through a cation-exchange reaction, in which ZnSe⋅0.5 N₂ H₄ hybrid nanobelts are employed as precursors. The detailed characterizations indicate the preservation of the belt-like morphology of the precursors due to the spatial confinement effect, which arises from the coated surfactant layer during the cation-exchange process. Simultaneously, CdSe nanobelts with porous and single-crystalline structures are formed following a complete exchange between Zn²⁺ and Cd²⁺ , the release of N₂ H₄ , and the atomic arrangement. The native photoelectric properties of the as-prepared porous single-crystalline CdSe nanobelts are systematically addressed based on the nanodevices fabricated with a single nanobelt and assembled nanobelt array. The results indicate that they present a rapid, stable, and repeatable photoelectric response. Moreover, as-prepared nanobelts exhibit highly selective photoelectric sensing toward Cu²⁺ with a low detection limit down to 0.1 ppm. To illuminate this phenomenon, a possible sensing mechanism is also discussed.