Facile in-situ preparation of MAPbBr3@UiO-66 composites for information encryption and decryption

Intermarriage of Halide Perovskites and Metal‐Organic Framework Crystals

“…Them icroporous nature of the composite enables it to react with exogenous chemicals,t hereby permitting facile, secure information encryption and decryption. [37] Fore xample,Pbions can react with benzene-1,3,5-tricarboxylic acid to construct the Pb-MOF.A lthough security ink containing the MOF is invisible,strong luminescence can be generated upon contact with MA halide precursors. [17] Theinsitu formation of perovskite within the MOF consumes Pb ions,which leads to framework defects and generates perovskite quantum dots larger than the inherent MOF pores.T herefore,t he efficient mass transfer creates as ecurity ink with rapid, reversible quenching (encryption) and regeneration (decryption) by polar solvents and MA halide solutions,r espectively (Figure 8).…”

Perovskite Nano‐Heterojunctions: Synthesis, Structures, Properties, Challenges, and Prospects

“…MAX to prepare MAPbI 2 X-HKUST-1 heterojunctions; [107] PbBr 2 -adsorbed MOF UiO-66 was directly synthesized and reacted with MABr to prepare MAPbBr 3 -UiO-66 heterojunctions. [108] The MOF of AMOF-1 was synthesized and ion exchange with Pb 2þ occurred, and reacted with CsX(X ¼ Cl, Br, I) to prepare CsPbX 3 -AMOF-1 heterojunctions. [109] Similarly, MAPbBr 3 -ZJU-28 heterojunctions were successfully synthesized with the perovskite NC size tunable from 7.7 to 11 nm by the reaction time ( Figure 15b).…”

Intermarriage of Halide Perovskites and Metal‐Organic Framework Crystals

“…TheMOF templates enable fine-control of the guest dimensions:itsuppresses aggregation of the guest, generating ligand-free surfaces and isolated perovskite quantum dots. [37,38] Thep rocess usually involves two separate steps: 1) loading of ap erovskite precursor into the MOFs,e ither during the MOF formation process,o ra sapost-synthetic treatment step;a nd 2) the nucleation and growth of perovskite,w hich usually occurs spontaneously under ambient conditions,o rc an be triggered by changing the temperature or by the introduction of perovskite anti-solvents. [39][40][41] Although this approach has been extensively studied for general MOF host-guest systems, [42,43] there are still some key aspects to consider for perovskite-MOF composites.1 )The stoichiometric ratio of the precursors within pores:A s ac onsequence of different affinities to different perovskite precursors (alkali metal/alkylammonium cations,lead cations, and halide anions), using ad ifferent MOF template is expected to lead to avariation of the precursor concentration within the pores,which may generate deep trap states for nonstoichiometric perovskites.…”

“…[39][40][41] Although this approach has been extensively studied for general MOF host-guest systems, [42,43] there are still some key aspects to consider for perovskite-MOF composites.1 )The stoichiometric ratio of the precursors within pores:A s ac onsequence of different affinities to different perovskite precursors (alkali metal/alkylammonium cations,lead cations, and halide anions), using ad ifferent MOF template is expected to lead to avariation of the precursor concentration within the pores,which may generate deep trap states for nonstoichiometric perovskites. [28,37] 2) Thermal, chemical, and structural stability of the host:T oinitiate the nucleation and growth of perovskites,t emperature variation or non-polar solvents may be implemented. In addition, the growth of guest crystals can impose mechanical stress on the framework.…”

“…Them icroporous nature of the composite enables it to react with exogenous chemicals,t hereby permitting facile, secure information encryption and decryption. [37] Fore xample,Pbions can react with benzene-1,3,5-tricarboxylic acid to construct the Pb-MOF.A lthough security ink containing the MOF is invisible,strong luminescence can be generated upon Angewandte Chemie Aufsätze contact with MA halide precursors. [17] Theinsitu formation of perovskite within the MOF consumes Pb ions,which leads to framework defects and generates perovskite quantum dots larger than the inherent MOF pores.T herefore,t he efficient mass transfer creates as ecurity ink with rapid, reversible quenching (encryption) and regeneration (decryption) by polar solvents and MA halide solutions,r espectively (Figure 8).…”