An Engineered Superhydrophilic/Superaerophobic Electrocatalyst Composed of the Supported CoMoS_x Chalcogel for Overall Water Splitting

Abstract

The development of high-efficiency electrocatalysts for large-scale water splitting is critical but also challenging.In this study,ahierarchical CoMoS x chalcogel was synthesized on anickel foam (NF) through an in situ metathesis reaction and demonstrated excellent activity and stability in the electrocatalytic hydrogen evolution reaction and oxygen evolution reaction in alkaline media. The high catalytic activity could be ascribed to the abundant active sites/defects in the amorphous framework and promotion of activity through cobalt doping. Furthermore,t he superhydrophilicity and superaerophobicity of micro-/nanostructured CoMoS x /NF promoted mass transfer by facilitating access of electrolytes and ensuring fast release of gas bubbles.B ye mploying CoMoS x /NF as bifunctional electrocatalysts,t he overall water splitting device delivered acurrent density of 500 mA cm À2 at alow voltage of 1.89 Vand maintained its activity without decayf or 100 h.

Noble-metal-free catalyst with enhanced hydrogen evolution reaction activity based on granulated Co-doped Ni-Mo phosphide nanorod arrays

“…Liu et al reported a hierarchical CoMoSx chalcogel on a Ni foam synthesized through an in-situ metathesis reaction. This electrocatalyst realized a current density of 100 mA•cm −2 below 1.74 V, which is lower than that of MoSx without Co doping (1.87 V) [20]. Dong et al prepared Co-doped β-molybdenum carbide (β-Mo2C) encapsulated by a N-doped carbon framework, which afforded a current density of 10 mA•cm −2 for the OER at a low overpotential of 1.6 V and provided a significant improvement in performance over β-Mo2C (over 1.8 V) [21].…”

“…In the next step, a solution-phase method [20] was employed to produce the Co-doped NiMoO4 precursor ((NiMo)1−xCoxO4/NF) with an estimated Co content of ~ 1 wt.%, as determined by semi-qualitative elemental mapping (Fig. S3 in the ESM).…”

“…Typically, 2-methylimidazole (4 mmol) was dispersed in methanol (25 mL), and the dispersion was mixed with methanolic Co(NO3)2•6H2O (1 mmol in 25 mL methanol) by stirring [20]. Subsequently, NiMoO4/NF was immersed in this solution and allowed to react for 24 h. When the reaction was finished, the sample was removed and washed with methanol several times to obtain (NiMo)1−xCoxO4/NF.…”

Recent developments in porous metal chalcogenides for environmental remediation and sustainable energy

“…The distinctive features of transition‐metal sulfide (TMS x ) chalcogel materials, including large porosity, extensive surface area, and exceptional electrochemical properties, have recently captured the attention of researchers in the field of catalysis. Several noteworthy studies have reported significant improvements in the catalytic performance and stability using TMS x chalcogels such as 40% GO/CoMo 3 S 13 , CoMoS x , and CoMoS x /nickel foam (NF) chalcogels 93,284,285 . Moreover, recent research has focused on understanding the gas–liquid–solid three‐phase interfaces in CoMoS x chalcogels on NF, which suggest that TMS x chalcogels can be promising materials for electrochemical catalysts 285 …”

“…Several noteworthy studies have reported significant improvements in the catalytic performance and stability using TMS x chalcogels such as 40% GO/CoMo 3 S 13 , CoMoS x , and CoMoS x /nickel foam (NF) chalcogels 93,284,285 . Moreover, recent research has focused on understanding the gas–liquid–solid three‐phase interfaces in CoMoS x chalcogels on NF, which suggest that TMS x chalcogels can be promising materials for electrochemical catalysts 285 …”