Well‐Defined Conjugated Reticular Oligomer “Blood Cells” and Conducting Polymer “Neurons” Constructing “Muscle”‐Biomimetic Electrocatalysts for Water Electrolysis

Abstract

AbstractCovalent organic frameworks (COFs) provide a tunable platform for water electrolysis. However, it is difficult to perform explicitly structural characterization for COFs due to the uncontrollable polymerization via the solvothermal method, which hinders the clear‐cut exploration of the COFs’ structure‐performance relationship in further applications. Here, the well‐defined conjugated reticular oligomers (CROs) are designed for the first time using an aqueous micellar strategy. The CROs have definite chemical structure and can be regarded as conjugated oligomers or defect‐free COFs segment. Using CROs and conducting polymer, three “muscle”‐biomimetic electrocatalysts are engineered for splitting water to H2 and O2. The self‐assembled “muscle”‐like structures guarantee fully exposed active sites, fast electron conduction and mass transfer (H2O/H2/O2). The “muscle”‐biomimetic poly(3,4‐ethylenedioxythiophene) (PEDOT)/CROs‐Ru exhibit superior electrochemical performance than the COFs‐Ru. In particular, the mass activity and turnover frequency (TOF) value of PEDOT/CROOH‐8‐Ru are ≈95 and 38 times that of the counterpart bulk Py‐COFOH. The theoretical calculation and the experimental results demonstrate that the CROs endow the electrocatalyst with an electron‐rich surface and enhance carrier mobility. The enhanced water electrolysis activity of CROs‐Ru can be attributed to the Schottky heterojunction suppressing the electron backflow, which facilitates the adsorption of hydrogen protons and hydroxides.