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Anionic metal−organic frameworks (MOFs) have attracted increasing attention due to the enhanced electrostatic interactions between their anionic frameworks and counter-ionic guests. Owing to these special host−guest interactions, anionic MOFs are beginning to have a large impact in the field of absorption and separation of ionic molecules and selective sensing of metal ions. Herein, two mesoporous anionic metal−organic frameworks, namely, [(CH 3 ) 2 NH 2 ] 6 [In 6 (OX) 6 (TCA) 4 ]•solvents (JOU-11) and [(CH 3 ) 2 -NH 2 ] 6 [In 6 (OX) 6 (TCPA) 4 ]•solvents (JOU-12) (H 3 TCA = tricarboxytriphenylamine; H 3 TCPA = tris((4-carboxyl)phenylduryl)amine; OX = oxalate), have been synthesized by using wheel-type [In 6 (OX) 6 -(COO) 12 ] 6− as building blocks. Structural analyses show that JOU-11 and JOU-12 show isoreticular three-dimensional frameworks with pyr topology. Due to their anionic frameworks and tunable pore window sizes, both compounds can be exploited for absorbing and separating cationic organic dyes. In addition, JOU-11 can be developed as a fluorescence "turn-off" sensor for selectively sensing Fe 3+ , whereas JOU-12 can be used for fluorescence "turn-on" sensing of Cu 2+ and Co 2+ ions.

In this work, a diketopyrrolopyrrole‐based 2D covalent–organic framework (COF) is realized and featured with broadband optical absorption and high solar‐thermal conversion performance. Moreover, a 3D hierarchical structure, referred to as COF‐based hierarchical structure (COFHS), is rationally designed to achieve an enhanced photothermal conversion efficiency. In this water evaporator, diketopyrrolopyrrole is immobilized into conjugated COF to achieve enhanced light absorption, whereas a porous PVA network scaffold is utilized to support COF sheets as well as to enhance the hydrophilicity of the evaporator. Due to this structural advantage, COFHS displays a high solar‐to‐vapor energy conversion efficiency of 93.2%. Under 1 sun AM1.5 G irradiation, a stable water evaporation rate of 2.5 kg m–2 h–1 can be achieved. As a proof‐of‐concept application, a water collection device prepared with the COFHS can achieve high solar‐thermal water collection efficiency of 10.2 L m–2 d–1 under natural solar irradiation. The good solar‐thermal conversion properties and high‐water evaporation rate make the COFHS a promising platform for solar‐thermal water production.