Solar-driven photocatalytic degradation of pollutants and promotion of interfacial evaporation have emerged as a promising approach to address environmental pollution and freshwater scarcity. However, the construction of integrated photothermal/photocatalytic materials and the underlying synergistic mechanisms are still poorly understood. Herein, a spherical evaporator (LCNB) was developed by rationally designing lignin-derived carbon-doped g-C₃N₄ (LCN) as a photothermal/photocatalytic material incorporated into sodium alginate and polyvinyl alcohol as a hydrophilic regulator, followed by cross-linking with CaCl₂. LCNB can self-assemble into a dynamic plane system for thermal localization and the gravitational changes of LCNB lead to rotation to dissolve precipitated salt and realize continuous desalination. Theoretical calculations revealed that carbon-doping reduces the band gap and thus improve the photothermal/photocatalytic efficiency. LCNB achieved a maximum evaporation rate of 1.64 kg m^-2 h^-1 under one solar irradiance while demonstrating no-salt accumulation for 12 h of continuous operation in 20wt% NaCl solution and an excellent photodegradation efficiency of 85.64% for tetracycline hydrochloride. Overall, this study establishes a promising framework for multifunctional solar evaporators by incorporating the LCN as the photothermal/photocatalytic material, effectively tackling desalination and pollutant degradation challenges while highlighting the potential of renewable resources in advanced material development.

中文翻译：

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用于连续海水淡化和协同水净化的一体化自清洁木质素衍生球形太阳能蒸发器

太阳能驱动的光催化降解污染物和促进界面蒸发已成为解决环境污染和淡水短缺的一种有前途的方法。然而，集成光热/光催化材料的构建和潜在的协同机制仍然知之甚少。在此，通过合理设计木质素衍生的碳掺杂 g-C₃N₄ （LCN） 作为光热/光催化材料，掺入海藻酸钠和聚乙烯醇作为亲水调节剂，然后与 CaCl₂ 交联，开发了球形蒸发器 （LCNB）。LCNB 可以自组装成动态平面系统进行热定位，LCNB 的重力变化导致旋转以溶解沉淀盐并实现连续脱盐。理论计算表明，碳掺杂降低了带隙，从而提高了光热/光催化效率。LCNB 在一次太阳辐照下实现了 1.64 kg ^{m-2 h-1} 的最大蒸发速率，同时在 20wt% NaCl 溶液中连续运行 12 h 时表现出无盐积累，盐酸四环素具有 85.64% 的优异光降解效率。总体而言，本研究通过将 LCN 作为光热/光催化材料，为多功能太阳能蒸发器建立了一个有前途的框架，有效应对海水淡化和污染物降解挑战，同时突出了可再生资源在先进材料开发中的潜力。