Starch, a naturally abundant and biodegradable material, holds great potential for sustainable applications but this potential is often limited by its inherent mechanical weakness and permeability to moisture and gases. In this study, we attempted to overcome those limitations by using MXene nanoplatelets to significantly enhance these properties. By incorporating 10 wt % MXene into starch films, we achieved considerable improvements in mechanical properties, with the Young's modulus and tensile strength increasing to 1923 MPa (from 456 MPa) and 19 MPa (from 10 MPa), respectively. Furthermore, the modified films exhibited a dramatic reduction in water vapor permeability by 92.9% and oxygen permeability by 74.0%, by creating a more efficient barrier that could extend the usability of starch-based materials in various industries such as in packaging materials. Notably, the films retained their biodegradability, decomposing after 6 weeks in soil, underscoring their environmental friendliness. Our findings clearly demonstrate the feasibility of enhancing biopolymer functionalities while maintaining the biodegrability and eco-friendliness of starch, by using MXene nanoplatelets.

Root rot is a soil-borne disease primarily caused by fungi. The malady not only decrease the ability of absorbing water and nutrients, but also severely threat agricultural productivity. Recently, a new family member of twodimensional (2D) transition metal carbide materials, MXene (Ti3C2Tx), has gained much interest as a promising approach to control fungi. However, the efficient use and mechanism of MXene in protecting plant against pathogenic fungus are still rarely reported. Here, the synthesized MXene were first characterized by the atomic force microscopy (AFM), scanning electron microscopy (SEM), dynamic light scattering (DLS), transmission electron microscopy (TEM) and X-ray photoelectron spectra (XPS). MXene application in soil obviously enhanced the root rot disease resistance of T. grandis. Soil microbial community analysis indicated that the abundance of Fusasium genus was decreased by 68.32% after MXene treatment. Further, MXene specially affected the permeability of Fusarium solani via damaging their cell membranes, thereby causing the disintegration and cell death of F. solani. In addition, MXene nanoflakes could transport into roots through T. grandis root air space, which resulted in the accumulation of lignin in roots via enhancing the expression and activities of lignin biosynthesis-related genes in T. grandis roots. Taken together, our finding pioneers comprehensive insights into the antifungal mechanism of MXene against F. solani and the efficiency use of MXene in protecting plant against pathogenic fungus, which will prompt the rapid development of nanotechnology in sustainable forestry.