Nanomaterial Design for Efficient Solar-Driven Steam Generation

Solar-driven evaporation of water is a simple and “green” way to achieve fresh water and water purification, yet evaporation of bulk liquid using solar energy is rather low in efficiency and may require a costly optical concentration system. Recently, the technology has been rejuvenated by advanced nanomaterials for localized solar heating and rapid evaporation in a confined environment. Design of innovative nanomaterials enables solar-driven vapor generation featured with direct utilization of solar energy with no additional energy input, minimized heat loss, high efficiency, and structural flexibility, as well as potential scalable production. Controlled micro-/nanostructures of broadband photothermal nanomaterials, as well as the macroscopic assembly of desired components, are essential for these next-generation solar-driven vapor generation systems. In this work, the recent advances in design and assembly of nanomaterials/structures for optimal solar-driven vapor generation are reviewed. The design/preparation strategies, working mechanisms, and performance of the solar-driven vapor generation based on these nanomaterials are discussed. Strategies for further optimization of materials/structures for solar absorption, heat management, and water transport are summarized for solar-driven vapor generation. This contribution concludes with comments on challenges and future opportunities in the field.