Incorporating Pt into Hierarchical Sulfides Showing Ultrahigh H2 Evolution Electrocatalytic Activity Comparable to Commercial Pt/C

The development of cost-effective and highly efficient catalysts is a promising area of research in the pursuit of clean energy. In this study, the design and synthesis of a multimetal sulfide loaded with low-content platinum nanoparticles (Pt) on nickel foam (NF) brings forth an efficient and cost-effective electrocatalyst PtS/Co₉S₈/MoS₂/Ni₉S₈@NF for hydrogen evolution reaction (HER). In the catalyst, Co₉S₈ and MoS₂ nanosheets attached onto Ni₉S₈ arrays to form a highly dispersed nanoflower morphology, which can provide robust substrates for Pt loading, while the low-content Pt remarkably enhances catalytic performance. In 1.0 M KOH and simulated seawater, at a current density of 10 mA cm^–2, the overpotentials of PtS/Co₉S₈/MoS₂/Ni₉S₈@NF are 37 and 278 mV, respectively, which are comparable to those of the commercial Pt/C electrode (35 and 265 mV). Moreover, the underlying mechanism behind the catalyst’s superior HER performance has been explored through density functional theory (DFT) calculations and in situ characterizations. DFT calculations of the catalyst indicated that the improved adsorption of H during the HER process is attributed to the mutual coupling between different compositions, leading to moderate binding between Pt and surface H. Meanwhile, in situ infrared absorption spectroscopy captured *OOH/*H intermediate species, demonstrating strong interactions between H₂O molecules and various active sites. In all, this study presents a new synthesis strategy via integrating trace amounts of noble metals into hierarchical sulfides, achieving exceptional catalytic performance while minimizing noble metal usage. Therefore, this work offers a new avenue for the design and development of high-performance catalysts with a low noble metal content.