Biomimetic Diode Solar Evaporator Enabling Efficient Transport-Kinetics-Dominated Evaporation and Localized Salt Crystallization

The past decade has witnessed substantial progress in boosting solar-driven interfacial evaporation via the innovation of materials and evaporator designs. However, how liquid transport kinetics, as critical factors governing interfacial evaporation, mediate solar interfacial evaporation remains unclear to date. In this study, we develop a Crassula muscosa-inspired diode evaporator (CMIDE) consisting of a cone frustum delicately covered by asymmetric ratchet structures in the convergent grooves, yielding a stable evaporation rate of 2.45 kg m–2 h–1 under one-sun illumination. More importantly, by controlling the structural parameters, including reentrant angle and depth, the liquid transport kinetics, including spreading time and film thickness, can be precisely controlled on the surface of CMIDE, further revealing the negative linear regulation mechanism by which these liquid transport kinetic factors influence solar evaporation performance. Such a CMIDE also maintains stable solar evaporation performance under high-salinity conditions, as evidenced by an evaporation rate of 1.96 kg m–2 h–1 for 20 wt % brine under one-sun illumination, as well as localized salt crystallization on the cone frustum’s top surface. These findings provide an effective route for how to design bionic structures to regulate liquid transport and enhance solar-powered interfacial evaporation for water treatment.