Highly Stable CsSnCl₃ Quantum Dots Grown in an Ionic Liquid/Gelatin Composite System through an In Situ Method

Abstract

Lead halide perovskite quantum dots (QDs) are controversial due to their high lead content. Tin, a low-toxic element with an outer electronic structure similar to that of Pb, becomes a strong candidate for preparing lead-free perovskite QDs. However, tin-based perovskite QDs, especially CsSnCl 3 QDs, exhibit poor environmental stability. Herein, we proposed an strategy for highly stable CsSnCl 3 QDs using an ionic liquid as a solvent and antioxidant and gelatin as a multidentate ligand and coating material through an in situ method ([AMIM]Cl/gelatin-QDs). The results showed that the abundant active groups of gelatin served as the nucleation growth center for QDs and further passivated QDs. At the same time, the long molecular chain of gelatin can coat the QDs to isolate the environment and fully protect QDs, and the size of QDs grown in gelatin was 5−10 nm. In addition, the oxidation resistance of ionic liquids and the halogen-rich environment formed also played an important role. Even if [AMIM]Cl/gelatin-QDs were treated with water and ultraviolet light simultaneously, its remaining fluorescence intensity was still above 60% within 72 h. Meaningfully, QDs endowed the composite system mildew resistance, which can resist the erosion of gelatin by molds, thereby realizing the system's long-term protection toward CsSnCl 3 QDs.

Selective fluorescence sensor for Fe3+ based on in situ synthesis of CsSnCl3 perovskite quantum dots with bone gelatin

“…The τ av of bone gelatin‐CsSnCl 3 QDs is significantly greater than that of other Pb‐free perovskite reported in the literature, as shown in Table 1. The results show that CsSnCl 3 QDs have fewer surface flaws in the [AMIM]Cl and bone gelatin composite systems 10 …”

“…The results show that CsSnCl 3 QDs have fewer surface flaws in the [AMIM]Cl and bone gelatin composite systems. 10 To test the stability of bone gelatin-CsSnCl 3 QDs, we dispersed them in water and in water with UV light for 55 h. Figure 2c shows that after being dispersed in water for 55 h, the bone gelatin-CsSnCl 3 QDs retain 96% of their photoluminescence intensity. The photoluminescence intensity remains above 80% even after both water and UV treatment.…”

“…However, the hazardous Pb element in Pb-based QDs can affect the environment and people, which restricts their practical usage in the fluorescence sensing industry. 8 Pb-free QDs have been used in photocatalysis, anti-bacterial, 9 and anti-mildew 10 applications, among others. They also have a lot of promise for use in fluorescence sensing.…”

“…Ionic liquids have been used in the perovskite industry to take use of their special properties. 10,21 We reported on bone gelatin-CsSnCl 3 QDs utilizing [AMIM]Cl as the solvent in this study, and we further explored the mechanism of action between bone gelatin and CsSnCl 3 QDs. After dispersing in aqueous solution for 55 h, the fluorescence intensity of bone gelatin-CsSnCl 3 QDs maintained over 96%.…”

“…In the context of adhering to the green and sustainable development path, our use of green solvents is expected to make the preparation process more environmentally friendly, while minimizing the damage caused by the use of organic solvents on the environment. Ionic liquids have been used in the perovskite industry to take use of their special properties 10,21 …”