Rapid Exfoliation and Surface Tailoring of Perovskite Nanosheets via Microwave‐Assisted Reactions

Abstract

A facile method for the exfoliation of layered oxide perovskites as well as surface modification of generated oxide nanosheets has been developed. Using rapid microwave‐assisted reactions, nanosheets from Dion‐Jacobson‐type perovskites were obtained and then subsequently functionalized with a variety of organics containing hydroxyl or amine groups. Initially, oxide nanosheets with tetra(n‐butyl)ammonium (TBA+) surface groups are produced in as little as 1 h from bulk HLnNb2O7 (Ln=La, Pr) perovskites. The TBA+ surface groups of these nanosheets can then be replaced with a variety of n‐alkyl alkoxy and n‐alkylammonium groups via fast microwave reactions (≤1 h). Beyond these simple n‐alkyl surface groups, nanosheets can also be produced with both saturated and unsaturated cyclic and linear alcohols. This synthetic approach appears widely applicable such that any saturated/unsaturated organic with hydroxyl or amine functional groups can be attached to oxide nanosheets. The rapid production of organic‐inorganic nanosheets coupled with controlled surface modification is of great significance for engineering functional composite materials with novel properties.

Microwave-assisted functionalization of the Aurivillius phase Bi2SrTa2O9: diol grafting and amine insertion vs. alcohol grafting

“… 1 , 10 – 15 Very recently, several reports have underlined the considerable progress offered by microwave activation for the functionalization of such layered perovskites, notably in terms of speed of the reactions. 6 , 16 – 18 In addition, apart from classical insertion or grafting reactions, 16 – 18 microwave-assisted post-synthesis modification 19 and exfoliation 20 have also been reported.…”

2D Perovskite Single Crystals for Photodetectors: From Macro‐ to Microscale

“…[60] In addition, a rapid microwave-assisted method was used in rapid exfoliation and postexfoliation surface modification from layered perovskite bulk, but the crystal size is small and uncontrollable because of high power. [61,62]…”

Highly Efficient Surface Modification of Layered Perovskite Nanosheets with a Phosphorus Coupling Reagent Making Use of Microchannels

“…In contrast, simplification of the experimental procedure could be achieved with surface modification after delamination of the layered materials. 12 An inorganic nanomaterial dispersed in an organic solvent can then be directly prepared by using a liquid−liquid biphasic system with an aqueous dispersion of an inorganic nanomaterial and an immiscible organic solvent dissolving a coupling agent. Thus, surface modification of metal nanoparticles, 13 metal oxide nanoparticles, 14−16 and metal oxide 10 and MXene 17 nanosheets has been achieved in liquid−liquid biphasic systems.…”

“…Interlayer surface modification of layered materials with organic compounds, on the other hand, has been developed using grafting reactions with several types of coupling agents, such as silane coupling agents, , alcohols, , and phosphorus coupling agents. , When the interlayer surface is modified with coupling agents bearing long-chain groups, a simple sonication process leads to the exfoliation of organically modified layered materials in organic solvents. , In this method, however, multiple steps requiring considerable time are generally necessary. In contrast, simplification of the experimental procedure could be achieved with surface modification after delamination of the layered materials . An inorganic nanomaterial dispersed in an organic solvent can then be directly prepared by using a liquid–liquid biphasic system with an aqueous dispersion of an inorganic nanomaterial and an immiscible organic solvent dissolving a coupling agent.…”