Efficient water desalination by using photoexcited TiN nanoheaters in nanoporous anodized aluminum oxide

抄録

We develop a cost-effective, reusable and efficient composite ceramic structures using anodized aluminum oxide (AAO) membrane and Titanium nitride (TiN) nanoparticles (NPs) to form “nanoscale solar steam generator.” This composite structure traps the absorbed solar energy at the composite-water interface to enable effective steam generation while suppressing the unnecessary heating of the subsurface water. Our studies have shown that photothermal performance of the TiN-AAO can be optimized by adjusting the pore diameter and TiN thickness. This structure has 92% steam generation efficiency under solar irradiation of 100 mW cm^-2. We have presented the mechanism of nano-heating, effects of the capillary action of water, as well as the thermal management in the AAO-TiN and polystyrene (PS) sheet system. A thermal insulation by a PS sheet was effective in improving the water evaporation speed. The proposed low cost and concise design make our material an excellent candidate for the portable solar steam generator.