Multiscale bamboo reconstruction enables adsorption-coupled solar evaporation for contaminated water treatment

Solar interfacial evaporation efficiently separates water from nonvolatile contaminants but provides limited control over pollutants retained at the evaporation interface. Here, we report a bamboo-derived adsorption-coupled solar evaporator (ASE) created by multiscale reconstruction of bamboo. The key innovation lies in a scale-differentiated bilayer design that couples active interfacial dye adsorption with phase-change separation: a polydopamine/ZIF-67-functionalized bamboo microfiber layer provides photothermal conversion and pollutant immobilization, while a directionally aligned bamboo nanofiber aerogel enables continuous water supply and thermal management. Isothermal gravimetric measurements yielded an estimated equivalent evaporation enthalpy of 1838.60 J g −1 , and PDA encapsulation decreased Co release by 99.1%. Under one-sun irradiation, the ASE achieved an evaporation rate of ~3.5 kg m −2 h −1 and remained stable in 20 wt% NaCl. Removal efficiencies reached 98.75% for methylene blue and 99.50% for rhodamine B, while metal–ion concentrations in condensates decreased by >99.5%. Surface analyses supported heterogeneous multisite adsorption. This work demonstrates a renewable material platform that couples pollutant immobilization with solar-driven water purification.