Revisiting the Old and Golden Inorganic Material, Zirconium Phosphate: Synthesis, Intercalation, Surface Functionalization, and Metal Ion Uptake

As a fascinating two-dimensional (2D) layered inorganic ion exchange material, zirconium phosphate (hereafter ZrP) has drawn interdisciplinary attention as an ion exchange material and a competent host for surface functionalization and intercalation. This is due to its captivating properties such as simple synthesis procedure, excellent ion-exchange capacity, excellent chemical, thermal, and radiolytic stability, tunable interlayer gallery, and good biocompatibility. Among all the well-known phases of ZrP, we restrict our discussion only to the alpha (α-ZrP) and gamma (γ-ZrP) phases for their efficient ion exchange performance and more tunable interlayer spacing. This review summarizes a panorama of the recent research progress on the synthesis, intercalation, and surface functionalization of ZrP with organic molecules, metal complexes, and metal ions for the design and fabrication of self-assembled monolayers, layer-by-layer assemblies, and nanocomposites. Within the confined gallery microenvironment of ZrP, usual molecules behave unusually with dramatic enhancement in the photophysical properties. The intercalation of metal complexes and their fascinating electronic properties will also be comprehensively highlighted in this review. Furthermore, for the first time, a cutting-edge advancement (2010 onward) of the versatile adsorption performance of ZrP-based materials for the uptake of toxic metal ions which include nuclear waste-related metal ions, heavy metal ions, and rare earth ions will be presented in detail. Last but not least, the review will conclude with the summary and future directions, which will provide new research opportunities for the development of ZrP based sustainable heterofunctional material.