Highly light-absorbent and corrosion-resistant porous SiC-CNT ceramics for durable solar interfacial evaporation

Ceramic-based interfacial evaporators have attracted considerable attention for use in solar-driven interfacial evaporation (SDIE) owing to their excellent structural stability and chemical durability. Herein, an integrated silicon carbide-carbon nanotube (SiC-CNT) ceramic evaporator was fabricated by incorporating CNTs into a porous SiC ceramic matrix, thereby integrating solar absorption, photothermal conversion, and water transport within a monolithic structure. The coupled effects of the CNT content and sintering temperature on the microstructure, pore characteristics, spectral absorption, and evaporation performance were systematically investigated. CNT incorporation enhanced broadband solar absorption, resulting in a maximum solar absorptance of 91.1%. More importantly, sintering-induced pore evolution produced distinct wavelength-dependent optical responses: absorption increased in the 200‒1100 nm range but decreased in the 1100‒2500 nm range, revealing the competing effects of pore coarsening and porosity reduction on light trapping and multiple scattering. The optimized ceramic containing 5 wt% CNTs and sintered at 2100 °C achieved an evaporation rate of 1.85 kg·m -2 ·h ‒1 under one-sun irradiation. The stable performance over 30 cycles as well as under acidic and alkaline conditions further demonstrated the potential of integrated SiC-CNT ceramics for application to durable SDIE.