Implementing Hybrid Energy Harvesting in 3D Spherical Evaporator for Solar Steam Generation and Synergic Water Purification

Solar-powered water evaporation provides a promising strategy for eco-friendly and cost-effective freshwater production. The exploration of high-performance photothermal materials and the rational design of evaporation architectures are crucial in promoting solar steam generation efficiency. Herein, multidimensional MXene-based composites with well-organized heterojunction nanostructures are proposed as bifunctional photothermal materials. The solar thermal conversion, chemical stability, and photocatalysis degradation properties are enhanced by anchoring Co₃O₄ nanoparticles on delaminated ultrathin MXene nanosheets, compared with that of Ti₃C₂ MXene. Based on these advantages, an integrated 3D spherical evaporator is constructed using the Co₃O₄/Ti₃C₂ MXene-based fabric. The evaporator shows its distinct advantages in maximizing the harvest of the hybrid energy from sunlight and the ambient environment, making it ideal for solar steam generation and synergetic water purification. An extremely high evaporation rate of 1.89 kg m⁻² h⁻¹ with a corresponding light-to-vapor energy conversion efficiency beyond the theoretical limit (130.4%) is achieved. More importantly, while the evaporation rate of the 2D evaporator significantly recedes upon the oblique sunlight irradiation, the evaporation rate of the 3D spherical evaporator is constantly high at different incident angles of sunlight, which satisfies the requirement of practical applications under moving sun.