The LibMOF project delivered on its overarching objective of developing high-throughput (HT) methodologies for synthesizing and characterizing metal-organic framework (MOF) thin films. To reach that overarching objective, a novel approach was developed using a mould with an array of 25 microreactor wells that enabled parallel solvothermal growth of MOF films under varied synthesis conditions. The developed HT platform allowed for systematic screening of parameters such as metal and linker concentrations, substrate surface, and temperature, using minimal reagent volumes (~0.1 mL per well). This methodology allowed 25 unique reaction conditions to be tested simultaneously on a single substrate, enabling the rapid optimisation of synthesis conditions to obtain suitable thin film morphology, homogeneity, and crystallinity. The resulting film deposits, each produced at unique conditions, were characterised using optical microscopy, SEM, and AFM.
The unprecedented effectiveness of the HT approach enabled the targeted characterization of MOF thin films with suitable properties. Films were studied using atmosphere-controlled dielectric spectroscopy, which provided relevant information for gas sensing based on capacitive signal readout. Simultaneously, spectroscopic ellipsometry has been used to study the optical properties of deposited structures. Spectroscopic ellipsometry measurements yielded quantitative data about the gas adsorption in MOF films and provided complementary information necessary to accurately interpret dielectric spectroscopy data.
The developed HT methodology enabled rapid, cost-effective, and environmentally friendly screening of synthesis conditions for the deposition of MOF thin films, which represents a major leap toward a more efficient research approach. These achievements mark a significant leap toward future AI-guided materials optimisation, which would significantly speed up the pace of discovery beyond what is achievable with traditional methods.
The results have been published in two peer-reviewed articles in high-impact open-access journals (Journal of Materials Chemistry A, ACS Applied Electronic Materials), as well as in one open-access preprint, which is at the time under review in a high-impact journal.