A scalable, eco-friendly, and ultrafast solar steam generator fabricated using evolutional 3D printing

Abstract

Solar steam generation is an emerging technique that harvests intermittent sustainable solar energy for large-scale wastewater purification and desalination. However, the application of solar steam generators is currently restricted by their high cost and low solar-thermal conversion efficiency. Herein, we demonstrate a highly efficient, portable, low cost and reusable interfacial solar evaporator fabricated using three-dimensional (3D) printing technology. Using cues from nature, the 3D-printed honeycomb lightweight evaporators are designed to have microporous capillary channels, which facilitate water transportation for continuous solar steam generation. The graphene coating on the surface enables efficient solar-to-vapor energy transfer, and a thermally insulating photopolymer suppresses heat loss. The optimized 3D-printed solar evaporator thus has a rapid evaporation rate of 2.67 kg m⁻² h⁻¹ (normalized to the projection area) and a high apparent solar-to-heat efficiency of 178.5% under 1 sun irradiation. The device shows outstanding antifouling properties and hence has wide application prospects for long-term domestic wastewater reduction and desalination of high-salinity brine.