Taro stem-inspired aerogel with vertically ordered channels for high-efficiency solar seawater desalination

Abstract

Solar-driven interfacial evaporation has emerged as a promising technology for freshwater production and energy sustainability. It leverages solar energy to efficiently evaporate water, enabling sustainable seawater desalination and wastewater purification. However, designing efficient evaporators that combine rapid water transport and high salt resistance remains a significant challenge. Drawing inspiration from the long-range ordered vasculature and anti-gravity water management mechanisms of taro stem, we fabricated a biomimetic aerogel featuring vertically aligned microchannels through a unidirectional freezing ice templating method. The aerogel integrates a core–shell SiC@C composite as a high-performance photothermal converter, a mechanically robust PVA/PAM double network forming the channel walls, and hydroxyapatite (HA) nanorods serving as both a thermal insulation skeleton and a mechanical reinforcement. In contrast to conventional aerogels with randomly oriented and tortuous pores, the biomimetic honeycomb architectures with vertically aligned channels endow the material with exceptional water transportation, thereby facilitating efficient salt ion diffusion and mitigating salt crystallization. Under 1 sun illumination (1 kW m⁻²), the aerogel achieves a high evaporation rate of 3.24 kg m⁻² h⁻¹, substantially outperforming most reported evaporators with disordered porous structures. The unique vertical channel configuration ensures continuous and stable desalination performance, highlighting its great potential as an effective solution to address global freshwater scarcity.