Solar evaporation enhancement using floating light-absorbing magnetic particles

摘要

We have demonstrated a new strategy for enhancing solar evaporation by using floating light-absorbing materials. Floating Fe_3O_4/C magnetic particles with an average size of 500 nm were synthesized by carbonization of poly(furfuryl alcohol) (PFA) incorporated with Fe_3O_4 nanoparticles. The Fe_3O_4/C particles had a BET surface area of 429 m~2 g~(-1), and a density of 1.44 g cm"3. Because of their hydrophobicity and a bulk packing density of 0.53 g cm""3, Fe_3O_4/C particles were floatable on water. Our results indicated that these Fe_3O_4/C particles enhanced the water evaporation rate by as much as a factor of 2.3 in the solar evaporation of 3.5% salt water. In addition, Fe_3O_4/C particles were easily recycled using a magnet, and stable after being recycled three times. Our work provides a low-cost and highly effective way for accelerating solar evaporation for industrial applications such as solar desalination, salt production, brine management and wastewater treatment.