Robust Sustainable Biomass Fluorescent Wood for Heavy Metal Removal and Solar Water Purification

Abstract

ABSTRACT Heavy metal contamination in aquatic environments represents a severe threat to global ecological security. While conventional method such as fluorescent probes, have been investigated for detection purposes, their real‐world deployment remains hampered by inherent drawbacks such as limited sensitivity and poor reusability. Herein, we introduce a “living” composite material, fabricated by incorporating ratiometric fluorescent metal–organic frameworks (MOFs) into the natural microchannels of wood, setting a new benchmark for environmental remediation. Specifically, ZIF‐8‐hybridized fluorescent carbon dots (DRZ‐CDs) were firmly immobilized onto a delignified wood (DW) matrix through electrostatic interactions and chelation, resulting in a bifunctional material (DRZ‐CDs‐DW). The composite exhibits good performance, with an exceptional Cu 2+ adsorption capacity of 298.72 mg/g and a low detection limit of 2.3 nM. Going beyond high removal efficiency, we further demonstrate a transformative “waste‐to‐resource” strategy, in which the exhausted adsorbent (DRZ‐CDs‐DW+Cu 2+ ) is transformed via in situ sulfidation into a photothermal evaporator (DRZ‐CDs‐DW‐CuS). The resulting system achieves an evaporation rate of 3.54 kg·m −2 ·h −1 , generating purified water, and is suitable for practical uses such as plant irrigation. In summary, by effectively merging fluorescent carbon dot (CDs) functionalization, wood structural engineering, and solar‐driven interfacial evaporation, this work realizes a synergistic combination of environmental cleanup and resource upcycling.