More from less: improving solar steam generation by selectively removing a portion of evaporation surface

Using minimal photothermal material to achieve maximum evaporation rate is extremely important for practical applications of interfacial solar evaporation technology. In this work, we found that with the increase in the size of evaporation surfaces, the evaporation rate decreased. Both experimental and numerical simulation results confirmed that when the evaporation surface size increased, the middle portion of the evaporation surface acted as a “dead evaporation zone” with little contribution to water evaporation. Based on this, the middle portion of the evaporation surface was selectively removed, and counterintuitively, both the evaporation rate and vapor output were increased due to the re-configured and enhanced convection above the entire evaporation surface. As such, this work developed an important strategy to achieve a higher evaporation rate and increased vapour output while using less material.