Designable Photo‐Responsive Micron‐Scale Ultrathin Peptoid Nanobelts for Enhanced Performance on Hydrogen Evolution Reaction

Abstract The development of high‐reactive single‐atom catalysts (SACs) based on long‐range‐ordered ultrathin organic nanomaterials (UTONMs) (i.e., below 3 nm) provides a significant tactic for the advancement in hydrogen evolution reactions (HER) but remains challenging. Herein, photo‐responsive ultrathin peptoid nanobelts (UTPNBs) with a thickness of ≈2.2 nm and micron‐scaled length are generated using the self‐assembly of azobenzene‐containing amphiphilic ternary alternating peptoids. The pendants hydrophobic conjugate stacking mechanism reveals the formation of 1D ultralong UTPNBs, whose thickness is dictated by the length of side groups that are linked to peptoid backbones. The photo‐responsive feature is demonstrated by a reversible morphological transformation from UTPNBs to nanospheres (21.5 nm) upon alternative irradiation with UV and visible lights. Furthermore, the electrocatalyst performance of these aggregates co‐decorated with nitrogen‐rich ligand of terpyridine (TE) and uniformly‐distributed atomic platinum (Pt) is evaluated toward HER, with a photo‐controllable electrocatalyst activity that highly depended on both the presence of Pt element and structural characteristic of substrates. The Pt‐based SACs using TE‐modified UTPNBs as support exhibit a favorable electrocatalytic capacity with an overpotential of ≈28 mV at a current density of 10 mA cm −2 . This work presents a promising strategy to fabricate stimuli‐responsive UTONMs‐based catalysts with controllable HER catalytic performance.