Carbon Ink Enhanced\nCalcium Alginate-Based Hydrogel\nwith Response Surface Methodology Optimized for Solar-Driven Salt-Tolerant\nDesalination

The global shortage of freshwater resources is becoming\nmore and\nmore serious; therefore, it is necessary to obtain freshwater by desalinating\nseawater resources. Solar-driven interfacial photothermal evaporation,\nwhich is an environmentally friendly and energy-efficient technology,\nhas been used to desalinate seawater for water purification and production.\nHerein, the IPCA hydrogel with abundant pores consisting of carbon\nink as a photothermal conversion material and PU sponge loaded with\ncalcium alginate as a water transport medium was successfully prepared\nand used to obtain portable water. The parameters of the synthesized\nIPCA are optimized by Response Surface Methodology analysis, and it\nwas found that the IPCA exhibits a high evaporation efficiency of\n3.779 kg m<sup>–2</sup> h<sup>–1</sup> and up to 95.98%\nof photothermal conversion capacity under one solar intensity. It\nmaintains a high evaporation efficiency and salt resistance after\n10 cycles of evaporation in actual seawater. Moreover, IPCA shows\na high removal of various organic dye pollutants in wastewater. The\nresults suggest a new approach for the preparation of simple, efficient,\nand green solar evaporators in practical application.