Solar-driven water purification has been deemed as a cheap, green and renewable technology to mitigate water shortage and pollution. Herein, a biomass aerogel with hydrophilic-hydrophobic Janus structure has been prepared as solar water evaporator, which is achieved by partially modifying hydrothermal-treated loofah sponge (HLS) with reduced graphene oxide (rGO). It's a rare design philosophy that HLS serves as a substrate with large pores and hydrophilic properties to ensure continuous and effective water transport, and the hydrophobic layer with rGO modification guarantees good salt resistance in seawater desalination with high photothermal conversion efficiency. As a result, the obtained Janus aerogel, p-HLS@rGO-12, exhibits impressive solar-driven evaporation rates of 1.75 kg m^-2h⁻¹ and 1.54 kg m^-2h⁻¹ for pure water and seawater respectively, with good cycling stability in the evaporation process. Furthermore, p-HLS@rGO-12 also demonstrates outstanding photothermal degradation of rhodamine B (greater than98.8 % in 2 h) and sterilization of E. coli (nearly 100 % in 2 h). This work offers an unusual approach to achieve highly efficient solar-driven steam generation, seawater desalination, organic pollutant degradation, and water disinfection simultaneously. The prepared Janus biomass aerogel holds great potential application in the field of seawater desalination and wastewater purification.

太阳能驱动的水净化被认为是一种廉价、绿色和可再生的技术，可以缓解水资源短缺和污染。在此，通过用还原氧化石墨烯（rGO）对水热处理丝瓜海绵（HLS）进行部分改性，制备了具有亲水-疏水 Janus 结构的生物质气凝胶作为太阳能水蒸发器。难得的设计理念是，HLS作为具有大孔隙和亲水特性的基底，以确保连续有效的水传输，而rGO改性的疏水层保证了海水淡化中良好的耐盐性，光热转换效率高。因此，获得的 Janus 气凝胶 p-HLS@rGO-12 表现出令人印象深刻的 1.75 kg m ^-2 h ^{-1太阳能驱动蒸发率}纯水和海水分别为1.54 kg m ^-2 h ^{-1 ，在蒸发过程中具有良好的循环稳定性。}此外，p-HLS@rGO-12 还表现出出色的罗丹明 B 光热降解（2 小时内大于 98.8%）和大肠杆菌杀菌（2 小时内接近 100%）。这项工作提供了一种不同寻常的方法来同时实现高效的太阳能驱动蒸汽发生、海水淡化、有机污染物降解和水消毒。所制备的剑锋生物质气凝胶在海水淡化和废水净化领域具有巨大的应用潜力。