The invention provides a microporous material which comprises a positively charged framework and can be utilized as an anion exchange material, typically in the treatment of waste materials in effluent streams, for example in the nuclear power industry. The microporous material facilitates the removal of undesirable anion species from solutions. One embodiment can include a silicophosphate comprising tetrahedra of PO4+ and SiO4. A method for the synthesis of a silicophosphate using a two-phase system which includes an organic phase comprising an organosilicon compound and an aqueous phase comprising a phosphoric acid is also provided.