Hofmeister Effect‐Enhanced Hydration Chemistry of Hydrogel for High‐Efficiency Solar‐Driven Interfacial Desalination

Abstract Solar‐driven water evaporation technology holds great potential for mitigating the global water scarcity due to its high energy conversion efficiency. Lowering the vaporization enthalpy of water is key to boost the performance of solar‐driven desalination. Herein, a highly hydratable hydrogel (PMH) network, consisting of modified needle coke as photothermal material and polyvinyl alcohol (PVA) as hydratable matrix, is crafted via simple physical cross‐linking method. When capitalizing on the PMH as evaporator for 3.5 wt% NaCl solution, a high evaporation rate of 3.18 kg m −2 h −1 under one sun illumination is deliver ed, unexpectedly outperforming that in pure water (2.53 kg m −2 h −1 ). More…

• NN
  National Natural Science Foundation of China

  Awards: U2003216, 52002014
• CP
  China Postdoctoral Science Foundation

  Award: 2019M660419
• FR
  Fundamental Research Funds for the Central Universities

  Awards: buctrc201929, buctrc202029