Biomimetic solar-driven interfacial evaporation system with effective desalination and volatile organic compounds removal performance

Solar-driven interfacial evaporation was an effective method for purifying polluted and salty water. However, the issue of addressing or reducing VOC contamination during evaporation remained unresolved in current systems. In this study, we developed a biomimetic solar-driven interfacial evaporation system using CS/BiOBr_0.4Cl_0.6/PVA-CNF (CBPC) hydrogels. Its unique hydrophilic bottom surface and low-density tip design allowed for continuous cycles of “salt accumulation ↔ salt removal”, while also degrading VOC. When treating water with 10 mg L⁻¹ phenol, it reached an evaporation rate of 2.47 kg m⁻² h⁻¹ and a VOC degradation efficiency of 88.4 %. Under real sunlight, this evaporator produced about 11 L m⁻² of clean water daily from reclaimed sources. It also removed 99.2 % of total dissolved solids (TDS) and 80.7 % of total organic carbon (TOC). This technology provided a new, efficient, and cost-effective strategy for developing evaporators designed for solar-driven water evaporation and wastewater purification.