Understanding the Unique Optical and Vibrational Signatures of Sequential Infiltration Synthesis Derived Indium Oxyhydroxide Clusters for CO2 Absorption

Sequential infiltration synthesis (SIS) is a vapor phase synthesis technique with potential to exert precise control over metal oxyhydroxide incorporation into polymer scaffolds. We observe strong size-dependent properties of InOx(OH)y few-atom clusters deposited with variable SIS cycle numbers within a polymethylmethacrylate (PMMA) matrix. Infrared and ultraviolet absorption spectroscopy reveal that the metal atom coordination and optical properties of the clusters depend on the number of SIS cycles performed as well as the choice of processing parameters. The incorporation of indium oxyhydroxide in PMMA via SIS improves the gravimetric CO2 absorption capacity, demonstrating a novel platform with potential for CO2 activation.