Trimetallic Zn–Co–Ni Selenide Nanoparticles as Electrocatalysts for the Hydrogen Evolution Reaction

Abstract

The evaluation and establishment of extremely efficient non-noble metal-based electrocatalysts for the bulk generation of hydrogen is one of the pivotal contemporary issues that requires immediate attention. In this work, we have synthesized trimetallic Zn−Co−Ni selenide nanoparticles (NPs) via a one-step hydrothermal method and explored their efficacy toward the electrocatalytic hydrogen evolution reaction (HER). The X-ray diffraction pattern investigations revealed that Zn and Co were doped into the cubic structure of NiSe 2 . Among the different compositions synthesized, trimetallic Zn 0.1 Co 0.3 Ni 0.6 Se 2 NPs demonstrated excellent electrocatalytic activity toward HER with a lesser overpotential of 121 mV at 10 mA cm −2 and a relatively lower Tafel slope of 35.3 mV dec −1 . Further, the electrocatalyst shows very good long-term stability for a duration of 12 h at 10 mA cm −2 in 0.5 M H 2 SO 4 . The morphological and structural investigations of Zn 0.1 Co 0.3 Ni 0.6 Se 2 NPs were probed in detail to understand their electrocatalytic performance. The judicious combination of the trimetals in an appropriate ratio is expected to modulate the electronic structure and trigger the electronic conductivity and active surface area, which, in turn, could boost the electrocatalytic HER process. Also, the various valence states of three different metal ions would afford a larger number of active sites in the trimetallic selenide NPs.

Structural Modulation through Se Vacancies on Zn-Doped NiSe2 Nanoparticles for Expediting Electrocatalytic Hydrogen Evolution

“…Further, in the case of Zn 0.4 Ni 0.6 Se 2 NPs, the core level spectra of Ni 2p and Se 3d display a slight positive peak shift in the binding energy compared to pure NiSe 2 (Figure B and C), demonstrating a strong interaction between NiSe 2 and dopant Zn 2+ ions . The incorporation of Zn 2+ as a dopant could effectively modulate the local electronic properties of NiSe 2 , which in turn would facilitate the electron transfer and improve the electrocatalytically active sites to enhance the HER process Figure D indicates the deconvoluted spectrum of Zn 2p, where two peaks occurred at 1045.76 and 1022.72 eV attributed to Zn 2p1/2 and Zn 2p3/2, which confirms that zinc is present as Zn 2+ .…”