Oxygen Sensing Performance Modulation Using Luminescent Ionic Copper Iodide Clusters Based on Mn(Ⅱ) Crystal Field Intensity

Abstract

Copper iodide (CuI) clusters have continued been to arouse increasing attention in many fields due to their high cost-performance, abundant reserves, hypotoxicity and structural diversity. Despite the oxygen sensing capability of coordinate CuI clusters has been demonstrated, the ionic counterparts with better structural stability hold potential to construct more durable sensing platform. However, the optical applications of the ionic CuI clusters have been hindered largely by their prominently weak emission. With the progress of ion assembly in recent years, ionic CuI clusters with specific emission properties can be attainable. Herein, two ionic dinuclear CuI clusters with Mn(Ⅱ) crystal field are introduced through fabricating sensing films to exhibit their oxygen sensing performance for the first time. The results reveal that both sensing films presented good reversibility, fast response associated with wide linear responses in the range from 0-90% gaseous O2. When the sensing behaviors of the two clusters were compared, different I0/I100 ratios of 6.6 and 2.1 are observed. Through investigating EPR spectra and time-resolved luminescence spectra, we highlight that different Mn(Ⅱ) crystal field intensity in corresponding clusters lead to distinct oxygen sensing behaviors. In our perception, the possible mechanism could offer new performance modulation strategy based on CuI clusters with multi-emission centers. Owing to the good structural stability of such materials, one of the clusters is used to demonstrate the dissolved oxygen sensing capability of the platform. The study constructs a stable sensing system and will pave the new way for optical application of the family of ionic CuI clusters.