Engineering a superhydrophilic TiC/C absorber with multiscale pore network for stable and efficient solar evaporation of high-salinity brine

Abstract

Achieving stable and efficient solar-driven evaporation of high-salinity brine is highly desirable while challenging because of salt inevitably blocking the evaporator surface during vapor generation. One of the effective resolvents is to construct macropores to ensure sufficient diffusion and convection of concentrated salt back into the bulk water. Herein, inspired by the interconnected pores of the balsa wood, superhydrophilic porous TiC/C absorber (SPTCA) with macro-/micro-/nano-pores network is successfully built by carbothermic reduction. The macropores channel plays the role of water transport, steam overflow, and salt ion diffusion backflow. The micro-/nano-pores channel enables broadband light absorption and keeps the moisture in a small range to achieve high-efficiency evaporation. With this rational design, the evaporator alloys for a stabilized evaporation of 1.78 kg/m2 h from simulated seawater for over 100 days and 1.75 kg/m2 h from high-salinity brine (15 wt.% NaCl) for over 50 days under 1 sun irradiation. The SPTCA provides a promising avenue for architecting the multiscale-pores network for solar desalination of high-salinity brine.