Two‐dimensional covalent organic frameworks (2D COFs) offer a designable platform to explore porous polyelectrolyte frameworks with periodic ionic skeletons and uniform pore channels. However, the crystallinity of ionized 2D COF is often far from satisfactory as the electrostatic assembly of structures impedes the ordered layered arrangement. Here, a multivariate synthetic strategy to synthesize a highly crystalline squaraine (SQ)‐linked zwitterionic 2D COF is proved. A neutral aldehyde monomer copolymerizes with squaric acid (SA) and amines in a controlled manner, resulting in the ionized COF with linkage heterogeneity in one tetragonal framework. Thus, the zwitterions of SQ are spatially isolated to minimize the electrostatic interaction and maintain the highly ordered layered stacking. With the addition of 85%–90% SA (relative to a total of aldehydes and SA), a fully SQ‐linked zwitterionic 2D COF is achieved by the in‐situ conversion of imine to SQ linkages. Such a highly crystalline SQ‐linked COF promotes absorptivity in a full spectrum and photothermal conversion performances, and in turn, it exhibits enhanced solar‐to‐vapor generation with an efficiency of as high as 92.19%. These results suggest that synthetically regulating charge distribution is desirable to constitute a family of new crystalline polyelectrolyte frameworks.

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Two-dimensional (2D) covalent organic polymers (COPs) featuring large surface areas and exposed active sites are desirable in the modification of electrode materials for electrochemical reactions. However, the rigid and planar conformation of 2D COPs limits the wrap of one-dimensional electrodes. Herein, we have proposed a molecular strategy to regulate in situ encapsulation of carbon nanotubes (CNTs) with 2D polyphosphazene. The stoichiometric control over the nucleophilic substitution reaction between hexachlorocyclophosphazene and amines allows for the oriented evolution around the surface of CNTs. The formed COP sheath is an ultrathin and uniform coating without granular deposition. Upon carbonization, the well-defined core/shell CNT composite was converted into the N,P-codoped carbon, exhibiting outstanding electrocatalytic oxygen reduction performance with a diffusion-limiting current density of 5.4 mA cm–2 and an electron transfer number of 3.97. The improved electrocatalytic activity originates from a high content of active N,P-containing catalytic sites uniformly distributed on porous carbon. This study provides a viable strategy to develop functional composite materials by modulating the flexibility of 2D COPs for 1D substrates, contributing to broad applicability.