Ultralow-content Pt nanodots/NiFe nanoparticles: interlayer nanoconfinement synthesis and overall water splitting

• Published in: Nanoscale Vol. 16; no. 15; pp. 7626 - 7633
• Main Authors: Ni, Yajun, Zhang, Wei, Li, Yaru, Hu, Shui, Yan, Hong, Xu, Sailong
• Format: Journal Article
• Published: 18.04.2024
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/d4nr00029c

Minimizing precious metal loading into electrocatalysts for water splitting is vital to promoting hydrogen energy technology toward practical applications. Low-content loading of precious-metal electrocatalysts is achieved by decorating precious metal nanostructures on co-electrocatalysts typically via surface confinement. Here, an electrocatalyst of ultralow-content Pt nanodots (0.71 wt%)/Ni 3 Fe nanoparticles on reduced oxidation graphene (Pt/Ni 3 Fe/rGO) is constructed for overall water splitting by pyrolyzing a single-source precursor PtCl 6 3− guest-intercalated MgNiFe-layered double hydroxide (MgNiFe-LDH) host via a distinctive interlayer confinement. Consequently, Pt/Ni 3 Fe/rGO demonstrates attractive overpotentials of 240 and 76 mV at 10 mA cm −2 for the oxygen and hydrogen evolution reactions (OER and HER), respectively, outperforming those of its /Ni 3 Fe/rGO counterpart. Moreover, the Pt/Ni 3 Fe/rGO Pt/Ni 3 Fe/rGO electrolyzer generates a current density of 10 mA cm −2 at 1.55 V, with a retention of 92.4% after 50 h. Furthermore, the measured specific activity and low transfer resistance, as well as the density functional theory (DFT) calculations, indicate that the active Pt/Ni 3 Fe in Pt/Ni 3 Fe/rGO can optimize the adsorption/desorption of reaction intermediates and thus boost OER/HER kinetics, all of which lead to enhanced performance. The results demonstrate that such an interlayer confinement-based synthesis strategy can allow for the design of cost-effective precious nanodots as potential electrocatalysts. An ultralow-content Pt nanodot (0.71 wt%) containing Pt/Ni 3 Fe/rGO electrocatalyst is constructed via an interlayer nanoconfinement, which exhibits satisfactory electrocatalytic performances for the OER and HER and as an electrolyzer.