Fabrication and Characterization of Amorphous Cobalt-Doped Molybdenum Sulfide for Hydrogen Evolution Reaction

Abstract

In the present study, hydrogen evolution reaction (HER) by alkaline water electrolysis was conducted without using a precious metal catalyst. We synthesized an amorphous cobalt-doped molybdenum sulfide by electrodeposition using different cobalt loadings. The amorphous Co-MoSx produced was characterized by scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The cobalt doping and sulfidation procedure resulted in the successful fabrication of a candidate catalyst for the catalytic hydrogen evolution in alkaline solution with high intrinsic activity. Cobalt incorporated amorphous MoSx exhibited 3 times higher HER activity than non-promoted MoSx.

Engineering the Electronic Structure of 2D WS2Nanosheets Using Co Incorporation as CoxW(1-x)S2for Conspicuously Enhanced Hydrogen Generation

“…Comparison of the fabricated Co x W (1− x ) S 2 nanosheet with the state‐of‐the‐art HER electrocatalysts in terms of Tafel slope and the overpotential required to achieve current density of 10 mA cm −2 . Data from references …”

“…Of the many approaches to improve the intrinsic activity of TMD's catalysis, doping of another atom is believed to play a significant role in optimizing the free energy of hydrogen adsorption . As such, experimental and theoretical studies reveal that metal or chalcogen doped TMDs are more active than undoped binary ones. Particularly, Co exhibits most significant promotional effect in catalyzing HER as evidenced in FeS 2 , MoS 2 , WS x , and MoS x by lowering the free energy barrier for H adsorption .…”

“…As such, experimental and theoretical studies reveal that metal or chalcogen doped TMDs are more active than undoped binary ones. Particularly, Co exhibits most significant promotional effect in catalyzing HER as evidenced in FeS 2 , MoS 2 , WS x , and MoS x by lowering the free energy barrier for H adsorption . Bonde et al put forward that cobalt atom in WS 2 leads to the decrement of the free energy of hydrogen adsorption on the exposed S‐edge thereby creation of new sites with higher activity than pristine WS 2 via density functional theory (DFT) simulation and calculation.…”

Small Dopants Make Big Differences: Enhanced Electrocatalytic Performance of MoS2 Monolayer for Oxygen Reduction Reaction (ORR) by N– and P–Doping

“…Especially, the MoS 2 nanosheets doped with various heteroatoms exhibit superior catalytic performance for the hydrogen evolution reaction (HER) [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50].…”

Nitrogen anion-decorated cobalt tungsten disulfides solid solutions on the carbon nanofibers for water splitting

“…Introducing heteroatoms into MoS 2 or WS 2 can increase the HER catalytic activity typically because of the significantly decreased Gibbs free energy of hydrogen adsorption [22][23][24]. It has been documented that forming a solid solution of M II (M=Co, Ni)WS can not only increase the HER activity but also improve the stability [25,26]. Tran et al indicated that the catalytic active sites are located at M II S cluster in the single Co-S-W phase, while the WS 2 layer functions as a coordination ligand stabilizing and tuning the catalytic performance [27].…”