Carbonized wood supported Fe3O4 nanoparticles for efficient solar-driven interfacial evaporation

Abstract

Magnetized wood (M–W) has been proposed to be used as an absorber in solar-driven interfacial evaporation. The M−W could gain an evaporation rate of 1.46 kg m−2 h−1 under the combined effect of sunlight and magnetic fields, which is 27 % higher than carbonized wood (C–W). To explore the mechanism, they were subjected to SEM, XPS, and water contact angle tests. It is revealing that M−W forms much more microchannels for steam diffusion. The M−W shows 97 % optical absorption within the whole wavelength, while the C–W is lower than 85 %, revealing the M−W can gather most of the solar radiation. Finally, the permeability coefficients of carbonized and magnetized woods are calculated by the CFD model. The permeability coefficient of the M−W is 20 % higher than the C–W, which can be attributed to Fe3O4 nanoparticles disturbing the steam growth in the magnetic field, hence decreasing the thickness of the liquid film covering the bubbles and improving the solar evaporation rate.