Ultrathin MoS₂ Nanosheets Vertically Grown on CoS₂ Acicular Nanorod Arrays: A Synergistic Three-Dimensional Shell/Core Heterostructure for High-Efficiency Hydrogen Evolution at Full pH

Abstract

A three-dimensional (3D) MoS2/CoS2 composite with shell/core heterostructure is in situ synthesized, which is composed of CoS2 acicular nanorod arrays and edge-terminated MoS2 nanosheets vertically grown on each CoS2 nanorod. Benefiting from the epitaxial growth of 2H-MoS2 on the surface of CoS2, the edge planes of ultrathin MoS2 nanosheets are significantly exposed. Due to the structural properties, a large number of direct contact areas are formed between MoS2 and CoS2, and a strong interaction between these two phases causes the electrons at the interface to be redistributed. Owing to the synergy of MoS2 and CoS2, significantly increased MoS2 edge sites, and improved mass transfer and electron transport, MoS2/CoS2 exhibits a remarkable catalytic ability for hydrogen evolution reaction (HER) at full pH. In 1.0 M KOH, 1 M PBS (pH = 7.0), and 0.5 M H2SO4, the overpotential at a current density of 10 mA cm–2 is 97, 196, and 126 mV, with Tafel slope of 78.7, 77.5, 42.6 mV dec–1, respectively. In addition to reporting a promising HER catalyst, this work will also provide a meaningful reference for designing 3D nanocatalysts.

A flower-like CoS2/MoS2 heteronanosheet array as an active and stable electrocatalyst toward the hydrogen evolution reaction in alkaline media

“…As shown in Fig. 5b, the 61 and CoS 2 -C@MoS 2 nano-bers (61 mV dec À1 ). 62 The small Tafel slope of 3D ower-like CoS 2 /MoS 2 HNSAs unveils a fast increase of hydrogen generation rate with increasing applied overpotential.…”

Strategies to improve electrocatalytic and photocatalytic performance of two-dimensional materials for hydrogen evolution reaction

“…The unique vertical growth morphology was conducive to achieving maximum exposure of the active sites. Huang et al [195] used the advantageous vertical growth method to prepare MoS2/CoS2 catalysts. The heterojunction catalyst RGO/MoS2/PD was prepared by Pandey et al [196]; during the heterojunction formation process, a phase transition was observed.…”

Molybdenum Disulphide Heterointerfaces as Potential Materials for Solar Cells, Energy Storage, and Hydrogen Evolution

“…Similarly, the vertically aligned 3D core/shell structures of MoS 2 on CoS 2 were grown to check their electrochemical performance; an improved performance of HER was observed. The surface morphology and electrochemical activity curves of these are shown in Figure b,c …”

“…b) SEM image of MoS 2 /CoS 2 . c) Electrochemical hydrogen evolution of various electrodes at 5 mV s −1 in 1 m KOH, Reproduced with permission . Copyright 2019, American Chemical Society.…”