Biomass‐Based Solar‐Thermal Evaporator with Surfactant Assistance for Water Purification

ABSTRACT Biomass materials, owing to their abundant availability and environmental friendliness, have been widely applied in interfacial water evaporation. However, biomass materials often suffer from poor solution processability and low solar‐thermal conversion efficiency. Herein, we propose a novel strategy for constructing highly efficient solar‐thermal evaporators: 1) The amphiphilicity of PEO‐PPO‐PEO tri‐block copolymer (F127) in aqueous solution was utilized to enhance the solution processability of the biomass based solar‐thermal material. 2) Ledum palustre L. powder (LPL) contains bio‐pigments such as quercetin, which gives it potential as a photothermal material. At the same time, its antibacterial components, including ursolic acid, allow it to be used to build an antibacterial solar‐thermal evaporator. The evaporator formed by integrating LPL and amphiphilic F127 achieved an evaporation rate of 1.66 kg m ⁻² h ⁻¹ and a water evaporation efficiency of 91.5% under 1.0 kW m ⁻² illumination. After 14 days of continuous outdoor operation, no bacterial colonization was observed on the evaporator surface or in the surrounding water. When exposed to stronger illumination, the device generated an output voltage of 158.09 mV in a custom‐built thermoelectric setup. The results demonstrate that the camphor biomass solar evaporator constructed with surfactant assistance represents a low‐energy, high‐efficiency water purification strategy.