Cellulose-based sponge@ZIF-8 from waste straws for water disinfection

Abstract

In this study, zeolitic imidazolate framework-8 (ZIF-8) nanoparticles can be readily in situ generated on the skeleton surface throughout the entire structure of cellulose-based sponges obtained from waste corn straws via a hydrothermal process. Taking natural corn straws as the basic ingredient, the Water Cellulose-based Sponge@ZIF-8 (WCSZ) composite inherits the highly porous structure of straws, which is beneficial for the movement of H₂O molecules in both horizontal and vertical directions. A robust H-bond topological network is weaved between abundant hydroxyl groups of the corn straw cell wall matrix and H₂O molecules in the honeycomb cellular structure. Based on the topological network, the WCSZ composite maintains sufficient mechanical compressibility and elasticity, which could sustain repeated squeezing without structural failure. The WCSZ composite can not only bear a compressive strain as high as 60% but also completely recover its original height after the load is removed, exhibiting excellent mechanical property. More importantly, the WCSZ composite also presents exceptional antibacterial activities after ZIF-8 nanoparticles were introduced (antibacterial rate: 99.9%). Consequently, the WCSZ composite is an ideal candidate for highly efficient elimination of bacteria as the reusable water treatment material.