Biopolymer-Induced Nanoarchitectured Superhydrophilic Carbon Aerogel with Efficient Transport Channel for Sustainable Water Purification

Global freshwater scarcity is driving the search for alternative aqua purification strategies. Solar-driven desalination has emerged as a leading solution, leveraging the abundance of seawater and salt lakes on Earth. In this study, we present an advanced interfacial solar-driven nanocarbon aerogel derived from ZIF-8 nanoparticles, reinforced with biopolymer-directed vertical channels <i>via</i> a facile ice-templating process. Specifically, we fabricated a vertically aligned ZIF-8 nanocarbon aerogel (VAZ8NCA) and compared it with a randomly ordered counterpart (RZ8NCA) obtained <i>via</i> conventional freezing. VAZ8NCA integrates hierarchical porosity, ultralow density, high interparticle connectivity, and enhanced hydrophilicity, thereby reducing vaporization enthalpy and improving light-to-heat conversion. The vertical channel alignment facilitates salt back diffusion, thereby mitigating fouling. The optimized VAZ8NCA sample, with a total porosity of 96.2% and a vaporization enthalpy of 1482.95 J g^-1, exhibits a high evaporation rate of 2.103 kg m^-2 h^-1 and a photothermal conversion efficiency of 86.6% under 1 sun. Furthermore, the fabricated evaporator achieves a salt rejection rate of 99.92% in simulated seawater, yielding water quality consistent with WHO and EPA standards while purifying oil-in-water emulsions, wastewater, and acidic or alkaline effluents. These findings provide a scalable pathway toward solar-driven desalination and enable various water purification applications.