Alloyed Re_xMo_1 – xS₂ Nanoflakes with Enlarged Interlayer Distances for Hydrogen Evolution

Abstract

Molybdenum sulfide (MoS2) has attracted significant attention due to its great potential as a low-cost and efficient catalyst for the hydrogen evolution reaction. Developing a facile, easily upscalable, and inexpensive approach to produce catalytically active nanostructured MoS2 with a high yield would significantly advance its practical application. Colloidal synthesis offers several advantages over other preparation techniques to overcome the low reaction yield of exfoliation and drawbacks of expensive equipment and processes used in chemical vapor deposition. In this work, we report an efficient synthesis of alloyed Re x Mo1–x S2 nanoflakes with an enlarged interlayer distance, among which the composition Re0.55Mo0.45S2 exhibits excellent catalytic performance with overpotentials as low as 79 mV at 10 mA/cm2 and a small Tafel slope of 42 mV/dec. Density functional theory calculations prove that enlarging the distance between layers in the Re x Mo1–x S2 alloy can greatly improve its catalytic performance due to a significantly reduced free energy of hydrogen adsorption. The developed approach paves the way to design advanced transition metal dichalcogenide-based catalysts for hydrogen evolution and to promote their large-scale practical application.

Facile and Scalable Colloidal Synthesis of Transition Metal Dichalcogenide Nanoparticles with High-Performance Hydrogen Production

“…Furthermore, the interaction between the transition metal cations (in this case, Mo 5+ ) and formamide can result in the formation of a donor–acceptor complex. This complexation can lead to an increase in the interlayer distance in the growing TMD nanoparticles . The XRD patterns of other TMD nanomaterials presented in Figure S4 exhibit the most intensive characteristic peaks at around 10° corresponding to 002 reflections.…”

“…The TMD nanoflakes were synthesized using a colloidal method at room temperature through a simple chemical reaction involving the chalcogen (S or Se) and metal (Mo, Ru, or Re) precursors. As reported in our previous works, , we successfully devised a versatile methodology for the synthesis of TMD nanomaterials at a moderate temperature (typically 170 °C). Notably, we observed a facile formation of donor–acceptor complexes between transition metal ions, specifically Mo, Ru, and Re, and formamide and its derivatives.…”

“…This complexation can lead to an increase in the interlayer distance in the growing TMD nanoparticles. 27 The XRD patterns of other TMD Comparison of overpotential at 10 mA cm −2 of ReSe 2 nanoflakes with different TMD-based catalysts published to date 12,23,34−47 32 The S 2p XPS signal exhibits two peaks at 163.2 and 161.9 eV, assigned to S 2p 1/2 and S 2p 3/2 , respectively. Additionally, two peaks at 163.8 and 162.6 eV can be attributed to supersaturated S−S bonds formed due to the low temperature used during the synthesis.…”

Pt nanoparticles anchored by oxygen vacancies in MXenes for efficient electrocatalytic hydrogen evolution reaction

“…Hydrogen is one of the promising candidates of future low-carbon energy since the only product of hydrogen combustion is water, providing a feasible and economical solution to the energy crisis caused by the consumption of non-renewable resources. 1–5 The electrochemical splitting of water can yield high purity hydrogen and has attracted much attention from researchers. 6–8 However, the hydrogen evolution reaction (HER) involves a two-electron transfer reaction with a high energy barrier and requires a large overpotential, which inevitably leads to low energy efficiency.…”

Discharging antibonding orbital electrons of 1T-MoS2 by S-rich treatment for promoting photocatalytic H2 evolution

“…Generally, the H adsorption–desorption ability can be effectively adjusted through the electronic density regulation of active S sites, 30–32 which can be achieved through introducing heteroatoms, 21,33–35 constructing heterojunctions, 36 and coupling with metals. 37,38 Although some research efforts have made towards electronic density regulation, the reason why the changed electron density can weaken or enhance the H adsorption of the S site is rarely discussed and explored in depth.…”