Superhydrophilic 2D Covalent Organic Frameworks as Broadband Absorbers for Efficient Solar Steam Generation

Abstract The intrinsic hydrophobicity and limited light absorption especially in the near‐infrared (NIR) region of porous organic polymers are two bottlenecks impeding their applications in solar steam generation (SSG). Herein, we develop a 1,4,5,8‐tetrakis(phenylamino)anthracene‐9,10‐dione (TPAD)‐based covalent organic framework (COF) (TPAD‐COF) featuring both superhydrophilicity and broad light absorption covering from the entire UV/Vis to NIR regions for SSG. TPAD‐COF serving as a highly efficient photothermal conversion material without any additives displays an excellent water evaporation of 1.42 kg m −2 h −1 and achieves a high energy conversion efficiency of 94 % under 1 sun irradiation. Further extension of the light absorption range of the TPAD‐based COF is realized through post‐synthetic modification by chelating BF 2 moieties. Systematic control experiments and analysis confirm that the hydrophilicity of photothermal conversion materials plays a more dominant role in the current TPAD‐based COFs for SSG.