Pt-1,1′-Bi(2-Naphthol) Nanostructures for Electrochemical H₂ Evolution in Alkaline Media

Abstract

This work improved the sluggish kinetics in an alkaline medium's electrochemical hydrogen evolution reaction (HER) by introducing the π-conjugated electronic effect from rationally designed Pt-1,1′-bi(2-naphthol) (BINOL) hybrid nanocomposites. The inorganic−organic hybrid nanocomposites were aqueously synthesized by a facile one-pot approach upon modulation of the surfactant concentration to precisely control the morphology in organic BINOL entities. This protocol led to different geometric nanostructures, including spheres (Pt-BINOL nanospheres) and lamellar flakes (Pt-BINOL nanoflakes), which allowed for fine-tuning of the d-band states of Pt NPs in the hybrid nanocomposites. In the two kinds of Pt-BINOL nanocomposites, the nanoflakes exhibited a low overpotential (24 mV) at the current density of 10 mA•cm −2 and the Tafel slope (19.1 mV dec −1 ), showing a superior HER efficiency not only much better than the nanospheres and the Pt/C catalyst but also comparable to the HER electrocatalysts in the late literature, with the lowest charge-transfer resistance (R ct ) 11.1 Ω and 1.12% of Pt-weight loading revealing that the Pt-BINOL nanoflakes are a cost-efficient electrocatalyst in alkaline HER. In conclusion, engineering the spatial arrangement of Pt NPs over the π-conjugated BINOL nanocarriers to enhance the Pt-catalyzed HER is important in developing efficient inorganic−organic hybrid nanostructures for generating H 2 energy.