Enhancing the catalytic activity of the alkaline hydrogen evolution reaction by tuning the S/Se ratio in the Mo(S_xSe_1−x)₂ catalyst

Abstract

The alkaline hydrogen evolution reaction (HER) plays a key role in photo(electro)catalytic water splitting technologies, particularly in water-alkali electrolyzers. Unfortunately, although transition metal dichalcogenide (TMD) materials, especially MoS2 and MoSe2, are considered efficient, Earth-abundant catalysts for the HER in an acidic electrolyte, they are much less effective under high pH conditions due to a sluggish water dissociation process (Volmer-step) and strong adsorption of the OH- intermediate on their surfaces. Herein we show a novel synergetic effect obtained by tailoring the S/Se ratio in Mo(SxSe1-x)2 alloys. We were able to influence the metal oxidation state and d-band to optimize the catalytic sites for HOH dissociation and OH- desorption while maintaining favourable M-H energetics. The Mo(SxSe1-x)2 (x = 0.58) catalyst exhibited high performance with an onset potential of -43 mV in 0.5 M KOH, i.e., ∼3 and ∼4-fold less than that for MoSe2 and MoS2, respectively. The results obtained in the current study have implications for the rational design of cost-effective electro-catalysts for water reduction based on TMD alloys.

A hydrothermally synthesized MoS2(1−x)Se2x alloy with deep-shallow level conversion for enhanced performance of photodetectors

“…This is because the radius of the Se atom is larger than that of the S atom, which leads to a change in the lattice distance. 23,24 The XRD patterns of all samples showed high noise, which indicates that the crystallinity of the samples was low, and no other peaks were observed, indicating that there were no phase impurities in the samples.…”

Co‐Doped MoSe2 Nanoflowers as Efficient Catalysts for Electrochemical Hydrogen Evolution Reaction (HER) in Acidic and Alkaline Media

“…Therefore, many strategies were employed to improve the performance of MoSe 2 . In addition to directly creating edge‐rich morphology, forming additional active catalytic sites by doping of the TMDC with other transition metals has gained much attention . High affinity of Co to the saturation of the edges of layered d ‐metal dichalcogenides is well established and is extensively applied in catalysis .…”

First‐Principles Prediction of the Structural, Electronic, and Magnetic Properties of Nonmetal Atoms Doped Single‐Layer CrS2

“…The prosperity of graphene motivated the arising of other 2D materials, such as silicene, phosphorene, arsenene, and antimonene as well as transition metal dichalcogenides (TMDs) . Single‐layer TMDs (MX 2 , M = TM, X = S, Se, Te) have become a hotspot of theoretical and experimental researches because of their promising applications in hydrogen evolution reaction catalysts, nanoelectronics, nanophotonics, absorber layer in solar cells, anode materials, field‐effect transistors, and so on.…”

“…The prosperity of graphene motivated the arising of other 2D materials, such as silicene, [1] phosphorene, [2] arsenene, and antimonene [3,4] as well as transition metal dichalcogenides (TMDs). [5][6][7][8][9][10] Single-layer TMDs (MX 2 , M ¼ TM, X ¼ S, Se, Te) have become a hotspot of theoretical and experimental researches because of their promising applications in hydrogen evolution reaction catalysts, nanoelectronics, nanophotonics, absorber layer in solar cells, anode materials, field-effect transistors, and so on. For example, Choi et al have reported that TMDs can be used as addition materials for the Li-Se batteries to prevent the decomposition of LiPSe, in addition, the TMDs can capture LiPSe more efficiently than graphene.…”