Preparation And Detection Performance Of MAPbBr₃@ZIF-8 Fluorescent Probe

The imbalance of ions in water environment will affect human health and ecological environment.Thus,it is necessary to design a detection method with high selectivity,anti-interference and sensitivity.Fluorescent probe detection method,which has the advantages of easy manipulation,simple to operate and convenient to carry compared with other analysis methods.It is a good strategy to use materials with excellent luminescence properties to prepare fluorescent probe.MAPb Br₃ is an excellent luminescent material,which has obvious application prospect in field effect transistor,light-emitting diode and solar cell.But,the structural instability seriously against the application of its excellent photoelectric performance.Zeolite imidazolium ester skeleton structure material（ZIF）is a kind of porous crystal material,which can load the guest to provide a stable environment.Our purpose in this study was to prepare novel fluorescence probe based MAPb Br₃@ZIF-8 and MAPb Br₃@ZIF-8Co_x%by embedding MAPb Br₃NPs in ZIF-8 and ZIF-8Co_x%for detecting the ions in water environment.The main achievements are as follows:（1）MAPb Br₃@ZIF-8 and MAPb Br₃@ZIF-8Co_x%composites were prepared at room temperature using 2-methylimidazolium zinc acetate,cobalt nitrate,lead bromide and methylamine bromine as raw materials.The results of XRD,BET,FTIR,SEM and EDS show that the powders were MAPb Br₃@ZIF-8Co_x%composites.The effect of concentration of doping Co²⁺ion the emission intensities of MAPb Br₃@ZIF-8Co_x%composite was investigated.When the ratio of Zn to Co is 95:5,the fluorescent light intensity of MAPb Br₃@ZIF-8Co_x%composites was the highest.（2）After soaking for 30 days,MAPb Br₃@ZIF-8Co_5%composite has good stability and excellent luminescent properties in water.The fluorescence response of composites to different metal ions in water was studied,indicating that MAPb Br₃@ZIF-8Co_5%had good selective anti-interference and sensitivity to the detection of Fe³⁺ion.The results of fluorescence sensing mechanism showed that the absorption band of Fe³⁺ion overlapped with that of MAPb Br₃ NPs,resulting in the quenching effect.The fluorescence quenching efficiency and detection limit of MAPb Br₃@ZIF-8Co_5%probe is 96.55%and 3.9×10^-5M,respectively.（3）MAPb Br₃@ZIF-8 has excellent stability in Na Cl solution and UV light treatment.The material has been used to detect anions in water,which show that the material has good selectivity and anti-interference to Cl O^-.Meanwhile,the response time of MAPb Br₃@ZIF-8 probe is less than 40 seconds,Besides,the detection limit and quenching constant of the probe are 31.9 n M and 0.141μM^-1,respectively,proving that the probe has excellent sensitivity.The quenching mechanism of Cl O^-detected by probe is due to electron transfer and dynamic quenching mechanism.The sensing stability was demonstrated by recovery rate with 94.6%-100.6%in natural environment,further exposing the potential application value of sensor.