Preparation of nanosheet by exfoliation of layered iron phenyl phosphate under ultrasonic irradiation

Synthetic layered iron phenyl phosphate (Fe(OH)(C6H5PO4H)1.6(H2PO4)0.4·5.1H2O: FePP), which is composed of a multilayer alternating bilayer of phenyl groups of the phosphates and amorphous iron phosphate phase, was exfoliated in ethanol under ultrasonic irradiation. The exfoliation of FePP was recognized at 10–10,000 ppm of FePP concentration. No reaggregation and reprecipitation of the nanosheets took place for at least 6 months of standing at room temperature. The UV–vis measurements indicated that the nanosheet dispersing solution possessed a UV absorption property which would be due to the charge transfer transition of Fe–O. The FePP nanosheet-doped silica gel with UV absorption property could be prepared by sol–gel process. The Beer's plot and EDX elemental mapping analysis for Fe and P revealed that the nanosheets are homogeneously dispersed in the silica gels.