Engineering Hierarchically Grooved Structures for Enhancing Interfacial Solar Thermal Water Purification

Inclined interfacial solar evaporators, especially those based on microgrooved Al substrates, show great potential for application in water purification to alleviate the water crisis. However, performance degradation caused by corrosion and contamination seriously affects their service life. To address this issue, a renewable heterojunction with TiO₂ as the inner layer and ZnO as the outer layer is formed on microgrooved Al by atomic layer deposition, which provides effective anticorrosion protection and efficiently kills adhered and planktonic bacteria. It also generates abundant photoinduced reactive oxide species to degrade organic pollutants and improves the water evaporation rate by enhancing water wicking and photothermal conversion. Moreover, the photodegradation and -OH regeneration properties of the heterojunction endow microgrooved Al substrates with renewable wicking performance and prolonged service life. This work provides a practical strategy to improve the performance of inclined interfacial solar evaporators to purify polluted water.