Tailoring MOF-303 Reinforced Biopolymer Hybrid Coatings with Hierarchically Porous Architectures for Precision Nitrogen Delivery in Sustainable Agriculture

In order to solve the problem of difficult precise nutrient release caused by loose pores in bio-based coated controlled-release fertilizers, this study explores the integration of Metal–Organic Framework (MOF) materials into bio-based coatings. Specifically, MOF-303 is synthesized and used to modify biocomposite coatings mainly derived from natural bio-polyol castor oil, which improved the controlled release performance through unique self-assembling and pore-forming properties of MOF-303. Characterization confirmed the successful incorporation of MOF-303 into the bio-based coatings, resulting in a smoother surface and fewer pores. Specifically, MOF-303 is synthesized and used to modify biocomposite coatings mainly derived from castor oil, which enhanced the controlled-release performance by adjusting the pore structure of the coating. The modified CRFs demonstrated improved controlled-release performance, with nitrogen (N) release periods extending from 63 days in unmodified coatings to 77 and 105 days with 1% and 1.5% MOF-303, respectively. Application trials on potted spinach revealed significant benefits, with yield increases of 37.51% and 30.83% under U and M1 treatment, respectively. This study highlights the potential of MOF-303-modified bio-based CRFs (MBCFs) to offer sustained and precise nutrient supply, thereby improving agricultural productivity and efficiency.