Inherently Micro/Nano-Patterned and Hydrophobic-Hydrophilic Inlay Natural Material Assembly for Efficient Nanoplastics Removal

Abstract

The biological and environmental hazards of nanoplastics are increasingly recognized, driving the need for effective and sustainable removal methods. Hydrophobic adsorbent materials with high surface areas are promising for capturing hydrophobic nanoplastics, yet achieving these properties in an eco-friendly, energy-efficient manner remains challenging. In this study, we turned to nature and proposed a synergistic hydrophilic-hydrophobic inlay strategy that employs hydrophilic bio-macromolecule β-chitin to assemble bio-microparticle pollen featuring inherent hydrophobicity and micro/nano-patterns. The resulting pollen-chitin sponge possesses a porous, hydrophobic architecture enriched with unique components such as aromatic rings and acetylamino groups. This assembly promotes strong interpenetration and interconnection between hydrophobic particles and hydrophilic lamellae, enhancing the interaction among hydrophobic pollen particles, water, and nanoplastics. The optimized arrangement of adsorption sites enables high-efficiency nanoplastics removal, achieving an adsorption capacity of up to 236.30 mg g⁻¹. The removal process is primarily driven by hydrogen bond interaction, hydrophobic interaction, physical interception, and π–π interaction. As a result, it successfully purified wastewater contaminated with multi-plastic particles and showed advantageous potential for removing various hydrophobic pollutants. Furthermore, sustainable recycling performance is demonstrated. The natural co-assembly system represents a practical, sustainable combination of multi-scale and multi-component biomass materials for mitigating hydrophobic pollution.