Portable Low-Pressure Solar Steaming-Collection Unisystem with Polypyrrole Origamis

Solar steaming has emerged as a promising green technology that can address the global issue of scarcity of clean water. However, developing high-performance, cost-effective, and manufacturable solar-steaming materials, and portable solar steaming-collection systems for individuals remains a great challenge. Here, a one-step, low-cost, and mass-producible synthesis of polypyrrole (PPy) origami-based photothermal materials, and an original portable low-pressure controlled solar steaming-collection unisystem, offering synergetic high rates in both water evaporation and steam collection, are reported. Due to enhanced areas for vapor dissipation, the PPy origami improves the water evaporation rate by at least 71% to 2.12 kg m^-2 h^-1 from that of a planar structure and exhibits a solar-thermal energy conversion efficiency of 91.5% under 1 Sun. When further controlling the pressure to ≈0.17 atm in the steaming-collection unisystem, the water collection rate improves by up to 52% systematically and dramatically. Although partial energy is utilized toward obtaining low-pressure, evaluations show that the overall energy efficiency is improved remarkably in the low-pressure system compared to that in ambient pressure. Furthermore, the device demonstrates effective decontamination of heavy metals, bacteria, and desalination. This work can inspire new paradigms toward developing high-performance solar steaming technologies for individuals and households.