Synthesis of Organic-Inorganic Hybrid Perovskite/MOF Composites from Pb-MOF Using a Mechanochemical Method

Abstract

The specific structure and diverse properties of hybrid organic-inorganic perovskite materials make them suitable for use in photovoltaic and sensing fields. In this study, environmentally stable organic-inorganic hybrid perovskite luminescent materials using Pb-MOF as a particular lead source were prepared using a mechanochemical method. Based on the fluorescence intensity of the MAPbBr₃/MOF composite, the mechanized chemical preparation conditions of Pb-MOF were optimized using response surface methodology. Then, the morphological characteristics of the MAPbBr₃/MOF composite at different stages were analyzed using electron microscopy to explore its transformation and growth process. Furthermore, the composite form of MAPbBr₃ with Pb-MOF was studied using XRD and XPS, and the approximate content of MAPbBr₃ in the composite material was calculated. Benefiting from the increase in reaction sites generated from the crush of Pb-MOF during mechanical grinding, more MAPbBr₃ was generated with a particle size of approximately 5.2 nm, although the morphology of the composite was significantly different from the initial Pb-MOF. Optimal performance of MAPbBr₃/MOF was obtained from Pb-MOF prepared under solvent-free conditions, with a milling time of 30 min, milling frequency of 30 Hz and ball-material of 35:1. It was also confirmed that the mechanochemical method had a good universality in preparing organic-inorganic hybrid perovskite/MOF composites.

Keywords: Pb–MOF; mechanochemical method; optical properties; organic–inorganic hybrid perovskite/MOF composites.

Figure 1

Impact of mechanochemical conditions on XRD of Pb–MOF (a) milling time; (b) milling frequency; (c) ball–material rate; impact of mechanochemical conditions on fluorescence intensity of MAPbBr₃/MOF composites (d) milling time; (e) milling frequency; (f) ball–material rate; the asterisks in subfigures (a–c) represent the main simulated characteristic diffraction peaks of Pb–MOF.

Figure 2

Response surface (a–c); contour plots (d–e) of the effect of mechanochemical preparation conditions on the luminescence intensity of MAPbBr₃/MOF composites.

Figure 3

Infrared spectrum (a) and XRD patterns (b) of Pb–MOF and MAPbBr₃/MOF composites; the yellow asterisks in subfigure b represent the main simulated characteristic diffraction peaks of Pb–MOF, the green asterisks represent the main simulated characteristic diffraction peaks of MAPbBr₃.

Figure 4

XPS elemental pattern and fitting analysis of Pb–MOF and MAPbBr₃/MOF composite (a) full spectrum; (b) Pb 4f spectra.

Figure 5

Pb–MOF and MAPbBr₃/MOF exposed to ambient atmosphere after 21 days (a) XRD (b) fluorescence stability of MAPbBr₃/MOF composite; the yellow asterisks in subfigure (b) represent the main simulated characteristic diffraction peaks of Pb–MOF, the green asterisks represent the main simulated characteristic diffraction peaks of MAPbBr₃.

Figure 6

Mechanochemical transformation to form MAPbBr₃/MOF (a) SEM image of Pb–MOF before reaction (b) SEM image of MAPbBr₃/MOF after addition of MABr (c) SEM image of MAPbBr₃/MOF mechanical milling for 3 min (d) SEM image of MAPbBr₃/MOF after mechanical milling; TEM images of MAPbBr₃/MOF after mechanical milling (e) 1 μm (f) 20 nm.

Figure 7

The fluorescence spectra of different doped MAPbBr₃/MOF composites (a) organoamine doped system; (b) metal bromide doped system; (c) halogen doped system.