Structural and Interfacial Characterization of a Photocatalytic Titanium MOF-Phosphate Glass Composite

Metal-organic framework (MOF) composites are proposed as solutions to the mechanical instability of pure MOF materials. Here, we present a new compositional series of recently discovered MOF-crystalline inorganic glass composites. In this case, formed by the combination of a photocatalytic titanium MOF (MIL-125-NH₂) and a phosphate-based glass (20%Na₂O-10%Na₂SO₄-70%P₂O₅). This new family of composites has been synthesized and characterized using powder X-ray diffraction, thermal gravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and X-ray total scattering. Through analysis of the pair distribution function extracted from X-ray total scattering data, the atom-atom interactions at the MOF-glass interface are described. Nitrogen and carbon dioxide isotherms demonstrate good surface area values despite the pelletization and mixing of the MOF with a dense inorganic glass. The catalytic activity of these materials was investigated in the photooxidation of amines to imines, showing the retention of the photocatalytic effectiveness of the parent pristine MOF.