Metal organic frameworks (MOFs) are an exciting class of materials due to their high porosity, surface area, and chemical and physical tunability.  One issue that continues to plague the MOF community is the so-called “surface barrier layer,” typically formed via reaction of the surface with air, which can act to decrease adsorption rates, and alters the chemistry of the native MOF surface. Surface barrier prevention aims to extend the lifetime of MOFs for use in a variety of applications, and typically consists of the use of capping agents on the surface of MOF particles. Herein, we conduct a fundamental study of adsorption in a MOF film (HKUST-1) grown using a layer-by-layer approach.  We explore alteration of the terminating MOF layer as a means to diminish or eliminate the surface barrier phenomenon utilizing a quartz crystal microbalance (QCMB) to grow an HKUST-1 film, and subsequently measure molecular adsoption. We also utilize X-ray photoelectron spectroscopy (XPS), a highly surface sensitive technique that allows surface characterization of the film following growth and subsequent exposure to air. Our findings stand to improve existing and emerging MOF applications on a larger scale.

Exploration and prevention of the surface barrier layer on HKUST-1 films

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.