Dual-functional natural rubber latex foam composites for solar-driven clean water production and heavy metal decontamination

Solar steam generation (SSG) offers a sustainable approach to fresh water production. Herein, a novel dual-functional natural rubber/carbon black composite foam evaporator is presented for a cost-efficient SSG system that both produces fresh water and eliminates heavy metals present in the water. The composite foam is produced using the Dunlop process, and in its optimized form, it absorbed >96 % of sunlight. The foam evaporator exhibited a thermal conductivity of 0.052 W/mK, a water evaporation rate of 1.40 kg/m2/h, converted 83.38 % of light to heat under 1 sun irradiation, and showed outstanding stability. The technology required to produce this composite foam is already available to make large-scale production feasible, while the natural raw materials are abundant. On the basis of its performance qualities, the rubber foam composite appears to be an excellent candidate for application as a viable solar absorber for SSG to produce fresh, clean water for commercial purposes.