Mesoporous iron phosphate/phosphonate hybrid materials

Relatively high surface area pure mesoporous iron-phosphorus oxide-based derivatives have been synthesized through an S⁺I^- surfactant-assisted cooperative mechanism by means of a one-pot preparative procedure from aqueous solution and starting from iron atrane complexes and phosphoric and phosphonic acids. A soft chemical extraction procedure allows opening the pore system of the parent as-prepared materials by exchanging the surfactant without mesostructure collapse. The nature of the pore wall can be modulated from iron phosphate up to hybrids involving approximately 30% of organophosphorus entities (phosphonates or diphosphonates). X-ray powder diffraction, transmission electron microscopy and surface analysis techniques show that these hybrid materials present regular unimodal disordered pore systems. Spectroscopic results (Fe-57 Mössbauer, XPS, UV-vis, FTIR and Raman) not only confirm the incorporation of organophosphorus entities into the framework of these materials but also provide us useful information to elucidate both the mechanism through which they are formed, and some details on their specific local structures.