Introducing ytterbium acetate to luminescent CsPbCl3 nanocrystals for enhanced sensitivity of Cu2+ detection

Abstract

In this study, we employed a luminescenct agent CsPbCl₃ perovskite nanocrystal for Cu²⁺ detection, and achieved a prominent enhancement in sensitivity by the introduction of ytterbium acetate (Yb(OAc)₃). The introduced Yb(OAc)₃ is capable of causing a morphology transformation of CsPbCl₃ nanocrystals from initial nanocubes into one-dimensional (1D) nanowires (NWs). The formed 1D CsPbCl₃ NWs paved a direct charge transport path and exhibited low defect density as well as superior conductivity, which were beneficial to accelerating the rapid electron transport from the luminescent agent to Cu²⁺, and to give rise to an efficient inhibition of undesired charge trap, respectively. Besides, AcO⁻ rendered a reduced steric hindrance during the formation of a copper-based counter-ion pair, thus improving the adsorption capacity of Cu²⁺ on the surface of the luminescent agent, CsPbCl₃ nanocrystals. As results, the 1D Yb(OAc)₃ passivated CsPbCl₃ NWs exhibited efficient luminescence quenching for enhanced detection sensitivity. This Yb(OAc)₃-involved system exhibited a detection limit as low as 0.06 nM in the Cu²⁺ detection window range from 0 to 1000 nM, and such value is optimal in the documented works for Cu²⁺ detection based on luminescent perovskite materials.