In-situ fibrillated sugarcane cell wall decorated with WO3-Ag nanocatalyst for efficient adsorption-photocatalytic removal of antibiotics from water

Abstract

Lignocellulose nanomaterials are extremely compelling in the remediation of organic wastewater, yet still present challenges regarding cost-efficiency, manufacturability, and scalability. Instead of a conventional bottom-up engineering, this study top-down designs multiporous, high specific surface area and anisotropic quaternized lignocellulose nano-sponge, based on the effectiveness of reactive deep eutectic solvent system on in-situ fibrillating sugarcane cell walls. The as-prepared sugarcane sponge reveals outstanding adsorption abilities for broad-spectrum antibiotics via a combination of intermolecular and electrostatic interactions, and serves as a desired carrier for hybrid nano-catalysts (e.g. WO3-Ag) with enhanced overall quantum efficiency. The developed sugarcane/WO3/Ag sponge integrating a functionality of adsorption enrichment with visible-light photocatalysis, can efficiently remove ∼ 99 % tetracycline/levofloxacin/norfloxacin at an initial concentration of 20 mg/L within 120 min at pH 7. The degradation pathway of antibiotics is inferred from the identified intermediates and primary active species. Additionally, the favorable mechanical strength, water stability and reusability of sugarcane/WO3/Ag sponge are demonstrated, which originate from the well-organized lignocellulose fibrils in in-situ fibrillated sugarcane cell wall and their intensive interactions with anchored nanoparticles. Our study offers a novel and feasible top-down nanostructure engineering strategy to manufacture high-performance lignocellulose-based nanocomposites towards environmental remediation.