Strain-activated porous helical-spiny-like PtCu with exposed high-index facets for efficient alkaline hydrogen evolution

Abstract

Integrating various control factors, including strain regulation, high-index crystal facets, and interfacial unsaturated coordination atoms, to improve the intrinsic performance of Pt-based catalysts is a very promising synthetic engineering approach for obtaining catalysts with ultra-high hydrogen evolution reaction (HER) activity. However, residual stress control and morphological regulation are inherently difficult to construct and, incidentally, keep the geometry. Herein, the phase engineering regulation method was used to synthesize porous helical-spiny-like PtCu (phs-PtCu) architecture with increased compressive strain. The porous pores in phs-PtCu further expose high-index facets and unsaturated atoms. Simultaneously, phs-PtCu exhibited an overpotential of only 434.7 mV under a high current density of 400 mA/cm2, much better than hs-PtCu and commercial Pt/C under alkaline conditions. Density functional theory (DFT) calculation indicated that the Gibbs free energy (ΔGH∗) of H–OH splitting and H∗ adsorption on the surface of phs-PtCu NWs (311) with the 3% compress strain exhibited the smallest value compared to phs-PtCu NWs and hs-PtCu NWs samples, revealing the adopted facile strategies play significant guidance to construct catalysts with high-index facets and strains.