Layer-by-layer self-assembly of pillared two-dimensional multilayers

We report Layer-by-Layer (LbL) self-assembly of pillared two-dimensional (2D) multilayers, from water, onto a wide range of substrates. This LbL method uses a small molecule, tris(2-aminoethyl) amine (TAEA), and a colloidal dispersion of Ti3C2Tx MXene to LbL self-assemble (MXene/TAEA)(n )multilayers, where n denotes the number of bilayers. Assembly with TAEA results in highly ordered (MXene/TAEA)(n) multilayers where the TAEA expands the interlayer spacing of MXene flakes by only similar to 1 angstrom and reinforces the interconnection between them. The TAEA-pillared MXene multilayers show the highest electronic conductivity of 7.3 x10(4) S m(-1) compared with all reported MXene multilayers fabricated by LbL technique. The (MXene/ TAEA)(n) multilayers could be used as electrodes for flexible all-solid-state supercapacitors delivering a high volumetric capacitance of 583 F cm(-3) and high energy and power densities of 3.0 Wh L-1 and 4400 W L-1, respectively. This strategy enables large-scale fabrication of highly conductive pillared MXene multilayers, and potentially fabrication of other 2D heterostructures.