Two-Dimensional High-Entropy Metal Phosphorus Trichalcogenides for Enhanced Hydrogen Evolution Reaction

Abstract

Developing earth-abundant and highly effective electrocatalysts for hydrogen evolution reaction (HER) is a prerequisite for the upcoming hydrogen energy society. Two-dimensional (2D) high-entropy metal phosphorus trichalcogenides (MPCh3) have the advantages of both near-continuous adsorption energies of high-entropy alloys (HEAs) and large specific surface area of 2D materials, which are excellent catalytic platforms. As a typical 2D high-entropy catalyst, Co0.6(VMnNiZn)0.4PS3 nanosheets with high-concentration active sites are successfully demonstrated to show enhanced HER performance: an overpotential of 65.9 mV at a current density of 10 mA cm–2 and a Tafel slope of 65.5 mV dec–1. Decent spectroscopy characterizations are combined with density function theory analyses to show the scenario for the enhancement mechanism by a high-entropy strategy. The optimized S sites on the edge and P sites on the basal plane provide more active sites for hydrogen adsorption, and the introduced Mn sites boost water dissociation during the Volmer step. Two-dimensional high-entropy MPCh3 provides an avenue for the combination of HEAs and 2D materials to enhance the HER performance, which also provides an alternative materials platform to explore and design superior catalysts for various electrochemical systems.

Tuning the Structural and Magnetic Properties in Mixed Cation MnxCo2–xP2S6

“…Figure a shows the XPS spectra for the mix-metal-alloyed compounds and indicates each sample’s respective Mn and Co oxidation states. The 2p 3/2 and 2p 1/2 at 640 and 652 eV correspond to the Mn 2p states while 781 and 795 eV correspond to the Co 2p states. − The states at 640 and 781.1 eV correspond to the Mn 2+ and Co 2+ in the octahedral sites. , Upon introduction of Mn into Co 2 P 2 S 6 , an inverse dependence between the intensity of the Mn and Co 2p states is observed, which further confirms the linear trend in the nominal stoichiometry of these alloyed systems. The fitting of the Mn 2p and Co 2p XPS spectra as shown in Figure S12 indicates the presence of shake-up satellite peaks as well as the expected 2p 3/2 and 2p 1/2 peaks.…”

High‐entropy alloy catalysts: From bulk to nano toward highly efficient carbon and nitrogen catalysis

“…116 3D, three-dimensional; HEA, high entropy alloy. O), 48,[122][123][124][125] sulfides (e.g., (CrMnFeCoNi)S x ), 111,126 metal dichalcogenides (e.g., (MoWVNbTa)S 2 ), 127 phosphates (e.g., (CoFeNiMnMo)P i ), 112,128 metal-organic frameworks (e.g., (NiCdCoCuZn)-ZIF), 129,130 metal carbide (and MXenes) (e.g., TiVNbMoC 3 and TiVCr-MoC 3 ), 113,114,131 and 2D van der Waals materials, 132 were also realized (Figure 5G). With the increase of research on high-entropy materials and innovative synthesis methods, more types of high-entropy compounds with various compositions and attractive characteristics can be explored in the future.…”

High Entropy van der Waals Materials

“…Figure 10. Electrochemical characterizations of Cox(VMnNiZn)1−xPS3 for HER [23] Although noble metals such as Pt, Ru, and Rh have impressive hydrogen evolution reaction (HER) activities, people are looking for more cost-effective and environmentally-benign alternatives. MPS3 system has been extensively studied as a promising candidate with suitable bandgap and high specific surface area.…”

“…Thus, introducing entropy to HEPS3 with tunable adsorption energies could be a promising technique for improving its catalysis properties. A series of Cox(VMnNiZn)1-xPS3 are synthesized and their corresponding HER performances are tested [23] . As demonstrated in Fig.…”