Plasmonic photothermic directed broadband sunlight harnessing for seawater catalysis and desalination

Abstract

Using readily available renewable resources, i.e. solar energy and seawater, to secure sustainable fuel and freshwater for humanity is an impactful quest. Here, we have designed solar thermal collector nanocomposites (SiO₂/Ag@TiO₂ core–shell) that possess efficient photothermic properties for highly targeted interfacial phase transition reactions that are synergistically favorable for both seawater catalysis and desalination reactions. The photothermic effect arising from plasmonic metal nanoparticles causes localized interfacial heating which directly triggers surface-dominated catalysis and steam generation processes, with minimal heat losses, reduced thermal masses and optics implementation. The solar thermal collector nanocomposites are seawater/photo stable for practical solar conversion of seawater to simultaneously produce clean energy and water. Finally, a proof-of-concept all-in-one compact solar hydrogen and distillate production prototype demonstrates the viability of sustainable photothermic driven catalysis and desalination of seawater under natural sunlight. Importantly, this approach holds great promise for enhancing energy and water productivity without considerable capital, infrastructure and environmental ramifications.