Water-heat separation evaporator design for efficient solar steam generation utilizing thermal radiation-convection hybrid mechanism

Solar-driven interfacial evaporation technology is a green and effective seawater desalination technology. Salt accumulation has a significant impact on the evaporation rate of solar evaporators, making it difficult to ensure long-term efficient operation. Hence, the solution to the problem of salt accumulation on the evaporator surface is crucial. In this work, based on the thermal radiation-convection hybrid mechanism, a columnar ink flower-based solar evaporator with a water-heat separation structure is proposed. The structure localizes the photothermally generated heat in the gas-water layer, suppressing heat diffusion into the bulk water. It can reduce heat loss and ensure adequate water supply, suppressing large amounts of salt accumulation on the absorber. The evaporator exhibits a high evaporation rate of 5.06 kg m⁻² h⁻¹ under the irradiation of 1 sun, which exceeds the theoretical limit of 1.4 kg m⁻² h⁻¹ thanks to its three-dimensional structure efficiently harnessing energy from the surrounding environment. The performance of the evaporator remains stable for 9 h of continuous evaporation, making it suitable for seawater desalination. This work provides a new strategy and technique for designing three-dimensional evaporators that can be applied to various environmental conditions.