Iron Phosphate Prepared by Coupling Precipitation and Aging: Morphology, Crystal Structure, and Cr(III) Adsorption

In this work, pure iron phosphate products with various morphologies and crystal structures were obtained by coupling fast precipitation in a microreactor and the aging process. Morphology control from amorphous nanoparticle to monoclinic microsheet or microsphere can be simply realized by only changing the addition of H3PO4 in the reaction system. Microscopic observations on morphology evolvement revealed the formation of different morphology, or crystal structure could be illustrated by the synergetic effect of precursor produced in the mixing unit and postgrowth from solution in aging generally. Furthermore, Cr(III) adsorption determinations confirmed monoclinic-phase FePO4 had a better adsorption capacity than amorphous FePO4, and microsheet FePO4 has potential as a Cr(III) adsorbent with rationality in crystal structure, surface area, and macroscopic size.