A platinum nanoparticle doped self-assembled peptide bolaamphiphile hydrogel as an efficient electrocatalyst for the hydrogen evolution reaction

Abstract

Noble metal-based nanomaterials have shown great potential for catalytic application with higher selectivity and activity. Owing to their self-assembly properties with various molecular interactions, peptides play an essential role in the controlled synthesis of noble metal-based catalysts with high surface area. In this work, a phenylalanine (F) and tyrosine (Y) based peptide bolaamphiphile is prepared by solution-phase peptide synthesis. The peptide bolaamphiphile readily self-assembles into a hydrogel with a cross-linked nanofibrillar network. The platinum nanoparticles (Pt NPs) are in situ generated within the cross-linked nanofibrillar network of the hydrogel matrix of the peptide bolaamphiphile. Benefiting from the synergistic properties of the Pt nanoparticles doped on three-dimensional fibrous networks, Pt6@hydrogel shows efficient catalytic activity for the electrochemical hydrogen evolution reaction (HER) in 0.5 M H₂SO₄ solution. The Pt6@hydrogel requires an overpotential of 45 mV at −10 mA cm⁻² with a Tafel slope of 52 mV dec⁻¹. The Pt6@hydrogel also shows electrocatalytic activity in basic and neutral pH solutions. The excellent activity and stability of Pt6@hydrogel for the HER shows great potential for energy conversion applications.