A general strategy for synthesizing hierarchical architectures assembled by dendritic Pt-based nanoalloys for electrochemical hydrogen evolution

Abstract

The development of multimetallic Pt-based nanostructures as high-performance cathodic electrocatalysts to be used in water-splitting devices for hydrogen generation is the focus of increasing attention. In this study, a family of hierarchical architectures constructed from dendritic quaternary PtFeRuRh, ternary PtFeRh or PtFeRu and binary PtFe nanoalloys are achieved via a general liquid-phase strategy for hydrogen evolution in alkaline electrolyte. Among them, the PtFeRuRh nanoalloys exhibit the lowest overpotential (20.0 mV at 10 mA cm−2) and Tafel slope (21.1 mV dec−1). At a potential of −0.07 V, the mass activity of the PtFeRuRh nanoalloy is 7.04 A mgPt−1, it is 6.97 times that of commercial Pt/C. The dendritic PtFeRuRh nanoalloys exhibit a negligible decrease in activity after 20 h of continuous testing at 10 mA cm−2/100 mA cm−2 and 3000 cyclic voltammetry cycles. In a practical application, the cell voltage of a PtFeRhRu (−) || IrO2 (+) couple is 1.568 V at 10 mA cm−2 with almost 100% faradaic efficiency. The turnover frequency of the PtFeRhRu electrocatalyst at 70 mV was 78.5 s−1, which is 11.71 times as large as that of commercial Pt/C (6.7 s−1).