Enhanced Activities in Alkaline Hydrogen and Oxygen Evolution Reactions on MoS₂ Electrocatalysts by In‐Plane Sulfur Defects Coupled with Transition Metal Doping

Abstract

Abstract2D transition metal disulfides (TMDs) are promising and cost‐effective alternatives to noble‐metal‐based catalysts for hydrogen production. Activation of the inert basal plane of TMDs is crucial to improving the catalytic efficiency. Herein, introduction of in‐plane sulfur vacancies (Sv) and 3d transition metal dopants in concert activates the basal planes of MoS2 (M‐Sv‐MoS2) to achieve high activities in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Acetate introducing mild wet chemical etching removes surface S atoms facilitating subsequent cation exchange between the exposed Mo atoms and targeted metal ions in solution. Density‐functional theory calculation demonstrates that the exposed 3d transition metal dopants in MoS2 basal planes serve as multifunctional active centers, which not only reduce ΔGH* but also accelerate water oxidation. As a result, the optimal Ni‐Sv‐MoS2 and Co‐Sv‐MoS2 electrocatalysts show excellent stability and alkaline HER and OER characteristics such as low overpotentials of 101 and 190 mV at 10 mA cm−2, respectively. The results reveal a strategy to activate the inert MoS2 basal planes by defect and doping co‐engineering and the technique can be extended to other types of TMDs for high‐efficiency electrocatalysis beyond water splitting.

Rational construction of loosely packed nickel nanoparticulates with residual HCOO ligands derived from a Ni-MOF for high-efficiency electrocatalytic overall water splitting

“…1,2 Due to the high combustion caloric value, sustainability and zero carbon dioxide emission, hydrogen (H 2 ) is considered as a promising alternative to fossil fuels. 3 Electricity-driven water dissociation represents one of the most promising and appealing approaches for the manufacture of high-purity oxygen and hydrogen, deriving from the oxygen evolution reaction (OER) at the anode and hydrogen evolution reaction (HER) at the cathode. 4,5 Until now, the main obstacles restricting the wide commercial application of water electrolysis devices are the lack of highly active and low-cost electrocatalysts, which contribute to low overpotential requirements for both HER and OER processes.…”

Effective regulation on catalytic performance of nickel–iron–vanadium layered double hydroxide for urea oxidationviasulfur incorporation

“…It can be clearly observed that there is an obvious response to the oxygen evolution reaction process for the S-NiFeV LDH electrode in 1.0 M KOH solution without urea, which originates from the oxidation peak of the Ni species (Ni 2+ /Ni 3+ ). [54][55][56][57] Depicted in Fig. 5 It is evident that the elaborate S-NiFeV LDH demonstrates a significantly improved UOR performance with a low onset potential of 1.34 V (vs. RHE), beyond which a dramatic increase in current density is determined.…”

“…It can be clearly observed that there is an obvious response to the oxygen evolution reaction process for the S-NiFeV LDH electrode in 1.0 M KOH solution without urea, which originates from the oxidation peak of the Ni species (Ni 2+ /Ni 3+ ). [54][55][56][57] Depicted in Fig. 5(b) are the LSV curves of the S-NiFeV LDH, NiFeV LDH, and NiFe LDH for the UOR, along with those of the commercial RuO 2 and bare NF as a contrast.…”

Mo-Doped Ni3S2 Nanosheet Arrays for Overall Water Splitting

“…10,11 Currently, it has been shown that Pt and RuO 2 / IrO 2 are superior catalysts, but at the same time, there is the problem of high price due to the scarcity of the earth's reserves. 12,13 Therefore, high activity and low-cost catalysts are crucial for the long term development of water electrolysis.…”

“…Overuse of fossil energy is increasing climate change and energy security concerns, and countries around the world are seeking to promote energy change and green development through vigorous development of clean energy methods. − Thanks to its high specific energy density, excellent conversion efficiency, and the cleanest combustion products, hydrogen energy has unparalleled advantages as an alternative energy source. − Electrolytic hydrogen production is a technology that uses water as the raw material to electrochemically process water into hydrogen and oxygen. The method is simple and efficient, with high purity of the prepared hydrogen, and the whole process is green and environmentally friendly. , However, the high reaction energy barriers of the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode require catalysts to resolve. , Currently, it has been shown that Pt and RuO 2 /IrO 2 are superior catalysts, but at the same time, there is the problem of high price due to the scarcity of the earth’s reserves. , Therefore, high activity and low-cost catalysts are crucial for the long term development of water electrolysis.…”