Use Of Metal-organic Frameworks Research Articles

Surface nano-architecture of a metal–organic framework

The rational assembly of ultrathin films of metal-organic frameworks (MOFs)--highly ordered microporous materials--with well-controlled growth direction and film thickness is a critical and as yet unrealized issue for enabling the use of MOFs in nanotechnological devices, such as sensors, catalysts and electrodes for fuel cells. Here we report the facile bottom-up fabrication at ambient temperature of such a perfect preferentially oriented MOF nanofilm on a solid surface (NAFS-1), consisting of metalloporphyrin building units. The construction of NAFS-1 was achieved by the unconventional integration in a modular fashion of a layer-by-layer growth technique coupled with the Langmuir-Blodgett method. NAFS-1 is endowed with highly crystalline order both in the out-of-plane and in-plane orientations to the substrate, as demonstrated by synchrotron X-ray surface crystallography. The proposed structural model incorporates metal-coordinated pyridine molecules projected from the two-dimensional sheets that allow each further layer to dock in a highly ordered interdigitated manner in the growth of NAFS-1. We expect that the versatility of the solution-based growth strategy presented here will allow the fabrication of various well-ordered MOF nanofilms, opening the way for their use in a range of important applications.

分子フレームワークを有する結晶性ナノ薄膜の作製と表面界面構造の解析

The rational assembly of ultrathin films of metal-organic frameworks (MOFs) —highly ordered microporous materials— with well-controlled growth direction and film thickness is a critical and as yet unrealised issue for enabling the use of MOFs in nanotechnological devices, such as sensors, catalysts, and electrodes for fuel cells. Here we explain our recent success of the facile bottom-up fabrication of such a perfect preferentially-oriented MOF nanofilm on a solid surface (NAFS-1), consisting of metalloporphyrin building units. The assembly of NAFS-1 was achieved by the unconventional integration in a modular fashion of a layer-by-layer (LbL) growth technique coupled with the Langmuir-Blodgett (LB) method. NAFS-1 is endowed with highly crystalline order both in the out-of-plane and in-plane orientations to the substrate, as determined by synchrotron X-ray surface crystallography. We expect that the versatility of the solution-based growth strategy presented here will allow the fabrication of various well-ordered MOF nanofilms, opening the way for their use in a range of important applications.