High‐Quality Thin Films of UiO‐66‐NH<sub>2</sub> by Coordination Modulated Layer‐by‐Layer Liquid Phase Epitaxy
A. Lisa Semrau, Roland A. Fischer
Abstract
Abstract We report the fabrication of macroscopically and microscopically homogeneous, crack‐free metal‐organic framework (MOF) UiO‐66‐NH 2 (UiO: Universitetet i Oslo; [Zr 6 O 4 (OH) 4 (bdc‐NH 2 ) 6 ]; bdc‐NH 2 2− : 2‐amino‐1,4‐benzene dicarboxylate) thin films on silicon oxide surfaces. A DMF‐free, low‐temperature coordination modulated (CM), layer‐by‐layer liquid phase epitaxy (LPE) using the controlled secondary building block approach (CSA). Efficient substrate activation was determined as a key factor to obtain dense and smooth coatings by comparing UiO‐66‐NH 2 thin films grown on ozone and piranha acid‐activated substrates. Films of 2.60 μm thickness with a minimal surface roughness of 2 nm and a high sorption capacity of 3.53 mmol g −1 MeOH (at 25 °C) were typically obtained in an 80‐cycle experiment at mild conditions (70 °C, ambient pressure).