Hierarchical Cobalt–Nickel Phosphide/Molybdenum Disulfide Hybrid Electrocatalyst Triggering Efficient Hydrogen Generation in a Wider pH Range

Abstract

Structural engineering of the molybdenum disulfide (MoS 2 ) retains its importance for the application of the hydrogen evolution reaction (HER) in a full pH range. However, the catalytic performance of reported MoS 2 -based materials, especially in neutral conditions, is unsatisfactory. Herein, an effective synergy between CoP, Ni 2 P, and MoS 2 nanosheets is established via a simple strategy, which constructs a self-supporting (CoP/Ni 2 P/MoS 2 −CC) electrode endowed with abundant catalytic active sites, optimal electronic structure, and improved charge transfer capability. The optimized CoP/Ni 2 P/MoS 2 −CC sample shows low overpotentials of 335, 119, and 211 mV at 100 mA cm −2 in neutral, alkaline, and acidic electrolytes with small Tafel slopes of 63, 62, and 82 mV dec −1 , respectively. Remarkably, the catalytic performance in neutral medium is superior to that of most of the reported MoS 2 -based hybrid electrocatalysts. Our work proves a facile and feasible strategy to promote the pH-universal catalytic activities of MoS 2 -based heterogeneous structures for hydrogen production.

Review—Recent Advances in Nickel Phosphide-Based Heterostructures for Electrochemical Hydrogen Evolution Reaction

“…7c). 103 This electrode gave high HER performance in various environments. Especially, it only requires a low potential of −119 mV to produce hydrogen gas at −100 mA cm −2 in alkaline solution, as depicted in Fig.…”

“…102 Copyright 2022, ChemCatChem. (c) Graphic flowchart of the preparation of CoP/Ni 2 P/MoS 2 −CC, (d) Polarization plots of various samples in alkaline solution.Reproduced with permission 103. Copyright 2023, ACS Applied Energy Materials.…”

Nanostructure engineering of ruthenium-modified electrocatalysts for efficient electrocatalytic water splitting

“…Earth-abundant transition metal oxides or hydroxides have attracted great interest in the design of high-effective electrocatalysts for overall water splitting because of their advantages, such as low cost, tunable activity, good stability and structural flexibility. 183,184 However, the poor intrinsic electrical conductivity and a limited number of active sites of metal oxides/hydroxides cause their poor electrocatalytic activity. Heteroatom Ru doping is a crucial and simple strategy for regulating the electronic structure of metal oxides/hydroxides and optimizing the reaction kinetics of catalysis.…”

Promoting water splitting by transforming its presence status for enhanced hydrogen evolution

“…3–6 The water-splitting H 2 evolution systems include the overall water splitting to produce H 2 and O 2 and half reaction of water splitting to generate H 2 . 7–9 The oxygen evolution reaction limits the efficiency of overall water splitting for H 2 generation, but the assistance of a sacrificial reagent can yield higher H 2 generation efficiencies. 10–13…”

“…22–25 For example, Zn-reduced 2H-MoS 2 , heterogeneous Ni 3 S 2 /FeNi 2 S 4 /NF and CoP/Ni 2 P/MoS 2 , and sulfur vacancies on MoS 2 yield enhanced H 2 evolution performance. 7,22,23,25 To date, however, the activity levels of transition-metal-based catalysts are still lower than those of Pt-based catalysts. 19,26 In addition, transition-metal-based catalysts usually have a complex preparation process and poor stability for catalyzing H 2 evolution, especially so for phosphide or sulfide catalysts, which result in the cost reduction of H 2 generation being limited.…”