Surfactant-assisted lamellar structuration of tunable Co-based hybrid nanosheets

Abstract

The controlled synthesis of metal organic nanosheets (MONs) still remains a challenge for scientists and is of primary interest in many research areas. In this study, we have developed a simple and reproducible one-pot synthesis method leading to tunable cobalt-based hybrid materials consisting of nanosheets with a well-defined morphology. The synthesis is performed via a solvothermal process assisted by primary amines acting as surfactants. The obtained materials are composed of ultrathin nanosheets with a rectangular morphology (width of about 50 nm and length greater than 100 nm). The different analysis techniques used show that the nanosheets are constituted by the alternation, in their width, of inorganic fringes (cobalt hydroxide) and organic ones (dicarboxylic acid) and that amine molecules stabilize their surface. 3D organisation of the nanosheets can be achieved at a synthesis temperature above 190 °C due to the interaction of alkyl chains of the stabilising amines. A multiparametric study based on SAXS experiments and TEM and PXRD analyses has highlighted the control of structural parameters by variations of some synthesis conditions. The inter-fringe distances are tunable from 1.0 nm to 1.5 nm through the length of the dicarboxylic linker and the distances between nanosheets can be modulated by the length of the alkyl chain of the primary amines. This efficient one-pot process seems to be very promising for the synthesis of tunable multiscale nanostructured MONs and can be implemented in many research areas, opening the way for various applications.