A Biomass Porous Carbon with Robust Salt Resistance Capacity for Continuously Efficient Solar-Driven Interfacial Desalination

TL;DR

This paper introduces a salt-resistant biomass-derived carbon material that efficiently produces freshwater from seawater using solar energy.

Contribution

A self-floating, biomass-derived porous carbon with robust salt resistance for solar-driven desalination is developed.

Findings

The material achieves an evaporation rate of 1.41 kg m−2 h−1 under 1 sun illumination with 88.9% efficiency.

It maintains stable evaporation in 3.5 wt% and 15 wt% NaCl solutions for over 12 hours.

The material successfully desalinates real seawater samples with high efficiency and durability.

Abstract

Solar-driven vapor generation (SDVG) emerges as a promising solution to the global freshwater crisis; yet, the scalable applications in seawater desalination are significantly hindered by the salt deposition. Herein, we report a self-floating biomass porous carbon with robust salt resistance derived from a simple, one-step carbonization of the Elymus nutans. The material features a natural hierarchical pore structure and superhydrophilicity, which work synergistically to ensure a rapid water supply and effectively prevent salt crystallization at the evaporation interface. Under 1 sun illumination (1 kW m−2), the biomass-derived carbon achieves a high evaporation rate of 1.41 kg m−2 h−1 with a solar-to-vapor conversion efficiency of 88.9%. More importantly, it demonstrates exceptional stability, maintaining stable evaporation in 3.5 wt% and 15 wt% NaCl solutions for over 12 h, with recorded rates of 1.33 and 1.16 kg m−2 h−1, respectively. The real seawater sample desalinating results verified the biomass-porous-carbon-realized high-efficient and robust solar-driven interfacial desalination. This work presents a sustainable, cost-effective, and salt-resistant material platform, offering a practical pathway for scalable solar desalination.

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