ABSTRACT
Halide perovskites have emerged as a highly promising class of photoelectric materials. However, the application of lead-based perovskites has been hindered by their toxicity and relatively weak stability. In this work, a composite material comprising a lead-free perovskite cesium copper iodide (CsCu2I3) nanocrystal and a metal-organic framework (MOF-801) has been synthesized through an in situ growth approach. The resulting composite material, denoted as CsCu2I3/MOF-801, demonstrates outstanding stability and exceptional optoelectronic characteristics. MOF-801 may serve a dual role by acting as a protective barrier between CsCu2I3 nanocrystals and the external environment, as well as promoting the efficient transfer of photogenerated charge carriers, thereby mitigating their recombination. Consequently, CsCu2I3/MOF-801 demonstrates its utility by providing both stability and a notably high initial photocurrent. Leveraging the inherent reactivity between H2S and the composite material, which results in the formation of Cu2S and structural alteration, an exceptionally sensitive photoelectrochemical sensor for H2S detection has been designed. This sensor exhibits a linear detection range spanning from 0.005 to 100 µM with a remarkable detection limit of 1.67 nM, rendering it highly suitable for precise quantification of H2S in rat brains. This eco-friendly sensor significantly broadens the application horizon of perovskite materials and lays a robust foundation for their future commercialization.
ABSTRACT
A good water-soluble and stable nanocomposite has been facilely prepared by the encapsulation of CsPbBr3 QDs via cetyltrimethylammonium bromide and mineral oil through sonication, namely CsPbBr3@CMO nanocomposite. Such method is very quick and simple without complicated instruments and strict conditions. The results reveal that the synthesized CsPbBr3@CMO nanocomposite is spherical with uniform size and shows remarkably good solubility and stability in water. Specifically, the fluorescent intensity of CsPbBr3@CMO nanocomposite in water is decreased by 0.76% after 3 h; this result is comparable with those in earlier studies, and the good stability in water might be owned to the hydrophobic core of the CsPbBr3@CMO nanocomposite. The prepared CsPbBr3@CMO nanocomposite has been applied as a sensitive fluorescent probe for monitoring hydrogen sulfide (H2S), and the fluorescence intensity (~ 524 nm) has a linear relationship with the concentration of H2S in the range 0.15-105 µM with a detection limit of 53 nM, demonstrating application for monitoring H2S in rat brain coupled with microdialysis apparatus with satisfied results. The present study not only provides a simple but sensitive approach for the detection of H2S in living body, but also paves the way for expanding the application of CsPbBr3 QDs to aqueous medium.
