ABSTRACT Adjusting the structural units of the covalent organic frameworks (COFs) to enhance polarization intensity can resolve the severe carrier recombination issue in piezocatalysis. Herein, two isomorphic COFs are synthesized and compared, including zwitterionic COF (SQ‐TAPT) with uneven charge distribution and neutral COF (PDA‐TAPT) with charge‐stabilization. Due to the increased Born effective charges arising from ionic bonding, SQ‐TAPT exhibits stronger ionic displacement polarization, resulting in a higher polarizability and enhanced piezoelectric response. Specifically, the d 33 value of SQ‐TAPT can reach 1.1 nm/V. Besides, all the Gibbs free energies in the active sites of SQ‐TAPT are lower than that of PDA‐TAPT, with the most optimal free energy of 0.56 eV. Moreover, the zwitterionic charge characteristic of SQ‐TAPT also gives it a superior hydrophilicity, conducive to hydrogen production in the process of water splitting. Attributable to the advantages of SQ‐TAPT, its piezoelectric hydrogen production rate can achieve 745.9 µmol·g −1 ·h −1 in the absence of co‐catalysts, which is 2.9 times higher than that of PDA‐TAPT, and exhibited a high piezocatalytic activity that is competitive with the state‐of‐the‐art catalysts reported. SQ‐TAPT demonstrates the feasibility of utilizing zwitterionic COFs in piezocatalysis. This research provides a novel perspective for modulating charge distribution, which in turn aids in designing piezoelectric catalysts based on molecular structure.
Yan et al. (Fri,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: