Tree-Like NiS2/MoS2-RGO Nanocomposites as pH Universal Electrocatalysts for Hydrogen Evolution Reaction

Hydrothermally Synthesized rGO/MnO2/MoS2 Nanohybrids as Superior Bifunctional Electrocatalysts for Oxygen and Hydrogen Evolution Reactions

This investigation delved into the field of bifunctional electrocatalyst water splitting, aimed at advancing sustainable energy by addressing the scarcity of efficient nonprecious electrocatalysts capable of facilitating both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). This study focused on nanohybrids consisting of hydrothermally synthesized rGO/MnO2/MoS2 composites and highlighted their efficacy as bifunctional electrocatalysts. The synergistic integration of rGO/MnO2/MoS2 enhanced the surface area, magnified electroactive sites, established a customized conductive arrangement, and provoked the efficiency in splitting of water. The nanohybrid displayed exceptional catalytic performance for the OER and HER, with significantly reduced overpotentials of 208 and 205 mV in 1 M KOH at 10 mA cm-2 current density, respectively. The findings underscore the potential of these cost-effective and environmentally friendly rGO/MnO2/MoS2 nanohybrids in advancing the field of electrocatalysis for renewable energy applications.

Multi-interface MoS2/Ni3S4/Mo2S3 composite as an efficient electrocatalyst for hydrogen evolution reaction over a wide pH range

The exploitation of cost-efficiently electrocatalysts for hydrogen evolution reaction (HER) over a wide pH range remains a challenge. Herein, we prepared a novel multi-interface MoS₂/Ni₃S₄/Mo₂S₃ composite on carbon cloth (CC) that acts as an efficient electrocatalyst over a wide pH range through a facile one-pot strategy, where (NH₄)₄[NiH₆Mo₆O₂₄]·5H₂O (abbreviated to NiMo₆) as a bimetallic precursor and Ni(NO₃)₂·6H₂O as one of the raw materials and salt are used together with thiourea (TU) for converting them into the MoS₂/Ni₃S₄/Mo₂S₃ load on CC (abbreviated as MoS₂/Ni₃S₄/Mo₂S₃/CC). MoS₂/Ni₃S₄/Mo₂S₃/CC-24 h shows a distinguished electrocatalytic performance towards HER with long-term stability in acid and alkaline media. It presents low overpotentials of 38 mV and 51 mV in 0.5 M H₂SO₄ and 1.0 M KOH at 10 mA cm^-2, respectively. This work can deliver a new idea to fabricate cost-efficient and long-term durability HER electrocatalysts over a broad pH range.

CoS2 Nanoparticles Anchored on MoS2 Nanorods As a Superior Bifunctional Electrocatalyst Boosting Li2 O2 Heteroepitaxial Growth for Rechargeable Li-O2 Batteries

Developing an excellent bifunctional catalyst is essential for the commercial application of Li-O₂ batteries. Heterostructures exhibit great application potential in the field of energy catalysis because of the accelerated charge transfer and increased active sites on their surfaces. In this work, CoS₂ nanoparticles decorated on MoS₂ nanorods are constructed and act as a superior cathode catalyst for Li-O₂ batteries. Coupling MoS₂ and CoS₂ can not only synergistically enhance their electrical conductivity and electrochemical activity, but also promote the heteroepitaxial growth of discharge products on the heterojunction interfaces, thus delivering high discharge capacity, stable cycle performance, and good rate capability.

Co doped MoS2 nanosheet: a stable and pH-universal electrocatalyst for efficient hydrogen evolution reaction

Generally, the hydrogen generation of non-noble metal based electrocatalysts is limited by the high overpotential and acid-base environment of electrolyte. Therefore, it is essential to develop hydrogen evolution reaction (HER)...

Electrocatalytically inactive copper improves the water adsorption/dissociation on Ni3S2 for accelerated alkaline and neutral hydrogen evolution

Nickel dichalcogenides, especially Ni3S2, present inferior alkaline and neutral hydrogen evolution activity due to their sluggish water dissociation kinetics. Although these materials hold promise as non-noble metal-based electrocatalysts for the hydrogen evolution reaction (HER) in acidic media, developing efficient strategies to enhance the water dissociation processes of nickel dichalcogenides in alkaline and neutral solutions is also an important area of research. The present work discloses an electrocatalytically inactive copper doping strategy to promote the water adsorption and dissociation process of Ni3S2 (Cu-Ni3S2) nanoparticles supported on nickel foam (NF) towards improving the alkaline and neutral hydrogen evolution reactions. Based on combined density functional theory calculations and electrochemical characterizations, the doping of Cu can accelerate the Volmer step and therefore strengthen the water adsorption/dissociation on the respective Ni sites and S sites during the HER process. As a result, the electrocatalyst exhibits superior and stable HER performance in both 1 M KOH and 1 M phosphate-buffered saline (PBS) solutions, with much lower overpotentials of 121 and 228 mV at a current density of 10 mA cm-2, respectively, in comparison to bare Ni3S2. We therefore conclude that the tailored control of the water adsorption/dissociation capability of Ni3S2 will open significant opportunities for the rational design of alkaline and neutral electrocatalysts from earth-abundant and stable materials.