Highly efficient solar vapour generation via hierarchically nanostructured gels

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Solar vapour generation is an efficient way of harvesting solar energy for the purification of polluted or saline water. However, water evaporation suffers from either inefficient utilization of solar energy or relies on complex and expensive light-concentration accessories. Here, we demonstrate a hierarchically nanostructured gel (HNG) based on polyvinyl alcohol (PVA) and polypyrrole (PPy) that serves as an independent solar vapour generator. The converted energy can be utilized in situ to power the vaporization of water contained in the molecular meshes of the PVA network, where water evaporation is facilitated by the skeleton of the hydrogel. A floating HNG sample evaporated water with a record high rate of 3.2 kg m−2 h−1 via 94% solar energy from 1 sun irradiation, and 18–23 litres of water per square metre of HNG was delivered daily when purifying brine water. These values were achievable due to the reduced latent heat of water evaporation in the molecular mesh under natural sunlight.

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G.Y. acknowledges financial support from a Sloan Research Fellowship, a Camille Dreyfus Teacher-Scholar Award, and a National Science Foundation award (NSF-CMMI-1537894). Molecular dynamics simulations were performed using a Summit supercomputer supported by the NSF (NSF-ACI-1532235).

Author information

Author notes

  1. These authors contributed equally: F. Zhao, X. Zhou.


  1. Materials Science and Engineering Program and Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA

    • Fei Zhao
    • , Xingyi Zhou
    • , Ye Shi
    • , Megan Alexander
    • , Samantha Mendez
    •  & Guihua Yu
  2. Department of Mechanical Engineering, University of Colorado, Boulder, CO, USA

    • Xin Qian
    • , Xinpeng Zhao
    •  & Ronggui Yang
  3. Key Laboratory of Photoelectronic/Eletrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China

    • Liangti Qu


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G.Y. supervised the entire project. G.Y., F.Z., X.Z. and L.Q. conceived the idea and co-wrote the manuscript. F.Z. and X.Z. performed materials fabrication and characterization and carried out data analyses. F.Z. and Y.S. performed the numerical simulations. X.Q., X.Z. and R.Y. performed the molecular dynamics simulations and differential scanning calorimetry measurements on the gel samples. M.A. and S.M. assisted in experimental work. R.Y. and L.Q. assisted in the design of experiments and interpretation of results. All the authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing interests.

Corresponding authors

Correspondence to Ronggui Yang or Liangti Qu or Guihua Yu.

Supplementary information

  1. Supplementary Information

    Supplementary Figures 1–21, Supplementary references.