Synthesis, Characterization and Nutrient Release Study of Zinc (II)-Aspartic Acid Framework Fertilizer

Abstract

The application of metal-organic frameworks (MOFs) in coating fertilizer nutrients is an innovative approach to forestalling problems observed from petroleum-based or polymer-based coating materials such as faster nutrient release and low hydrophobicity. Therefore, Zn-based MOF fertilizer has successfully been synthesized via co-crystallization from Zinc nitrate and aspartic acid with urea as the carrier encapsulants of Nitrogen, and phosphorus from potassium dihydrogen tetraoxophosphate(V) and ammonium tetraoxophosphate (V) respectively. The synthesized Zn-based MOF fertilizer was successfully characterized with FTIR-ATR, SEM-EDX, XRD, and TGA/DTG techniques. The FTIR-ATR affirms the successful incorporation of the precursors in the MOF fertilizer while the SEM coupled with EDX revealed polycrystalline morphology with the expected element in % weight. The XRD spectrum shows the Zn-based MOF fertilizer to be highly crystalline while the TGA/DTG curve indicates the material to stable up to 300 ℃. The nutrient release study indicates that the release of the nutrients at neutral pH environment is slow and sustainable while the mechanism of the release obeyed the Korsmeyer-peppas model.