Capturing solar energy for thermal conversion in a highly efficient manner for steam-electricity cogeneration is particularly opportune in the context of optimal solar energy utilization for concurrent water-energy harvesting. Herein, an integrative photothermal evaporator/thermogalvanic cell with the desired optical, heat, water, and electrochemical management for synergistic steam-electricity production is reported. Versatile layer by-layer assembly is employed to integrate a hydrogel/metal-oxide/polymer into a multilayer film with individually addressable thickness, composition, and structure. As such, the ultimate integrative multilayer film cell demonstrates a unified high surface area and conductive electrodes, broadband absorption, rapid water suction-ion exchange, and thermal insulation properties. Thus, the designed cell immensely suppresses heat losses, achieving a high solar thermal conversion efficiency of 91.4% and maximum power outputs of ≈1.6 mW m−2. Additionally, the self-floating, deformable, modular integral device presents appealing attributes such as salt-rejection for viable seawater desalination, high mechanical stability, and resilience to demanding operating conditions, and configurable on-demand/point-of-use tandem structure to maximize clean water and power generation value per area. This integrated strategy may provide prospective opportunities to reduce dependence on fossil fuels and freshwater inputs and solutions for renewable and decentralized clean water and electricity.
- steam generation