Graphene‐Like Hydrogen‐Bonded Melamine–Cyanuric Acid Supramolecular Nanosheets as Pseudo‐Porous Catalyst Support

Abstract Behaving as structural protectors and electronic modulators, catalyst supports such as graphene derivatives are generally constructed by covalent bonds. Here, hydrogen‐bonded ultrathin nanosheets are reported as a new type of catalyst support. Melamine (M) and cyanuric acid (CA) molecules self‐assemble to form the graphite‐like hydrogen‐bonded co‐crystal M‐CA, which can be easily exfoliated by ultrasonic treatment to yield ultrathin nanosheets with thickness of ≈1.6 nm and high stability at pH = 0. The dynamic nanosheets form adaptive defects/pores in the synthetic process of CoP nanoparticles, giving embedded composite with high hydrogen evolution activity (overpotential of 66 mV at 10 mA cm⁻²) and stability. Computational calculations, X‐ray photoelectron spectroscopy, and X‐ray absorption spectroscopy unveil the electron modulation effects of the nanosheets. This pseudo‐porous catalyst support also can be applied to other metal phosphides.