Polyallylamine-Functionalized Platinum Tripods: Enhancement of Hydrogen Evolution Reaction by Proton Carriers

Abstract

Tailoring the size, controlling the morphology, and designing the metal–organic interface are three promising strategies to improve the catalytic performance of monometallic noble-metal nanocrystals. In the “hydrogen economy” society, water electrolysis is viewed as one of the most promising technologies for hydrogen production. The design and synthesis of highly active and durable electrocatalysts for the hydrogen evolution reaction (HER) is vitally important for the development of the hydrogen economy. In this work, we successfully synthesized polyallylamine (PAA)-functionalized Pt tripods (Pttripods@PAA) with ultrathin and ultralong branches through a facile chemical reduction method in an aqueous solution of PAA. The morphology, structure, and composition of Pttripods@PAA were fully investigated by various physical techniques. The characterization results reveal that ultrathin and ultralong branches of Pttripods@PAA have a concave structure with high-index facets and that PAA strongly binds on the Pt surface as a proton carrier. Impressively, Pttripods@PAA display unexpected activity for the HER in acidic solution with an onset reduction potential of +19.6 mV vs RHE, which significantly outperforms currently reported monometallic Pt electrocatalysts. This activity is due to the increase in the local proton concentration on the Pt surface.

Polyethyleneimine functionalized platinum superstructures: enhancing hydrogen evolution performance by morphological and interfacial control

“…2C ). 27 , 28 Indeed, the zeta potential of the Pt-SSs@PEI is measured to be +44 mV due to the protonation of the –NH 2 groups on PEI, further confirming the binding of PEI onto the Pt surface. Compared to standard Pt 4f BE and N 1s BE values, the Pt 4f BE and the N 1s BE of the Pt-SSs@PEI exhibit a negative shift (1.09 eV) and a positive shift (1.12 eV), respectively, confirming the strong interaction between Pt atoms and –NH 2 groups ( Fig.…”

Platinum Nanostructure/Nitrogen‐Doped Carbon Hybrid: Enhancing its Base Media HER/HOR Activity through Bi‐functionality of the Catalyst

“…PtO x is quite stable in acid media during HER stability measurements, although a slight decrease in PtO x stability was observed. The HER performance (onset potential, overpotential, Tafel slope, exchange current density, and MA) of the Pt‐(PtO x )‐NSs/C catalyst have been compared with recently reported noble‐metal‐based catalysts and other non‐noble‐metal catalysts; the results are shown in Table S1 in the Supporting Information. This shows that this Pt‐(PtO x )‐NSs/C catalyst is better than or comparable to most of the recently reported catalysts.…”

“…Decreasing the diameter and increasing the branched structure enhances the surface area, resulting in higher porosity and activity . Platinum tripods, platinum octapods, platinum dendrites, and star‐like platinum nanowires (NWs) are known to be more catalytically active than that of commercially available Pt/C. Although several reports are available for ORR applications of 1D Pt nanostructures, there are few reports on hydrogen evolution and oxidation of 1D Pt nanostructures …”

Self‐Supported FeP‐CoMoP Hierarchical Nanostructures for Efficient Hydrogen Evolution

“…Electrochemical water splitting is considered to be a powerful means of large‐scale hydrogen production (2H 2 O+2e − →H 2 +2OH − ) . The noble platinum (Pt) metal nanomaterials are widely known to be the most efficient electrocatalyst for HER . Unfortunately, the application of Pt metal is extremely restricted in electrochemical water splitting device due to its inflated price and scarcity .…”