Origami system for efficient solar driven distillation in emergency water supply

Facing lack of infrastructure and no access of electricity, insuring drinking water for people during an emergency in remote area is becoming a great challenge. Here, we develop an origami as photothermal material based on daily pencil and paper for solar driven water purification in emergency. The drawn process destroyed the Van der Waals' force between graphite layers, making pencil cartridge exfoliated into thin graphite sheets. The paper fibers combined with graphite sheets were demonstrated with broadband absorption for solar energy harvesting and excellent hydrophilicity for water transportation. The origami structure effectively promoted the utilization of solar energy attributing to the increased solar absorption area and decreased solar reflection loss compared with planar system. In particular, the solar vapor efficiency and vapor evaporation rate of as-prepared origami system were reached to 80% and 1.16 kg m−2 h−1, respectively. In addition, the analog calculation results of COMSOL Multiphysics indicated that the origami structure was free from the dynamic solar motion. Herein, this nearly free cost, facile fabricated and high efficiency design would unlock a new generation of efficient water purification for water supply in emergency.