Pd Sulfidation‐Induced 1T‐Phase Tuning in Monolayer MoS₂ for Hydrogen Evolution Reaction

Abstract

For single-atom-layer hydrogen evolution reaction catalysts, enrichment of the 1T-phase in monolayer molybdenum disulfide is important to achieve ideal metal utilization efficiency and exposure of active surface atoms. Herein, it is discovered that the 1T-phase degree in monolayer MoS 2 can be enhanced through sulfidation of the Pd species deposited on MoS 2 (Pd x S y /1T-MoS 2 ). Raman and X-ray photoelectron spectroscopy reveal that the sulfidation-assisted phase transition results in considerably greater proportions of 1T-phase fraction (up to 86%) without using alkali-metal-based approaches. Observations of S-atom displacement/translation at the atomic level contribute to the understanding of the phase transformation of MoS 2 . The maximized surface atom activation and metal utilization efficiency in Pd x S y /1T-MoS 2 lead to unprecedentedly high mass activity (−3444 A mg Pd −1 ) and turnover frequency (1892 s −1 ), three orders of magnitude higher than those of commercial Pt/C 10 wt% (3.6 A mg Pt −1 and 3.6 s −1 ). The sulfidation-assisted 1T-phase enrichment has major implications for the designs of efficient electrocatalysts through MoS 2 phase engineering.

Sulfur-Vacancy-Rich Pd Metallene Sulfide Nanosheets for the Efficient Electrosynthesis of H2O2

“…However, compared with Pd metallene, the Pd 3d peaks in L-PdS-V s metallene are shifted toward higher binding energy due to the partial positive charge of Pd and local amorphous structure of Pd in L-PdS-V s metallene . In the S 2p spectrum (Figure f), the peaks at 161.5 and 163.0 eV correspond to S 2– 2p 3/2 and S 2– 2p 1/2 , respectively, which implies the presence of Pd–S bonds, and the peaks at 162.3 and 163.1 eV can be assigned to S 0 2p 3/2 and S 0 2p 1/2 due to the existence of S–S bond. , The result reveals that sulfur is coordinated with Pd and S atoms . Sulfurization regulates the electronic structure of the Pd surface and optimizes its adsorption of oxygen, easily promoting the ORR process …”

“…46 In the S 2p spectrum (Figure 2f), the peaks at 161.5 and 163.0 eV correspond to S 2− 2p 3/2 and S 2− 2p 1/2 , respectively, which implies the presence of Pd−S bonds, and the peaks at 162.3 and 163.1 eV can be assigned to S 0 2p 3/2 and S 0 2p 1/2 due to the existence of S−S bond. 47,48 The result reveals that sulfur is coordinated with Pd and S atoms. 38 Sulfurization regulates the electronic structure of the Pd surface and optimizes its adsorption of oxygen, easily promoting the ORR process.…”

Boosted Hydrogen Evolution via Molten Salt Synthesis of Vacancy-Rich MoSxSe2–x Electrocatalysts

“…Hydrogen, as a sustainable and clean energy vector, stands out as a viable substitute for fossil fuels, which not only contribute to environmental pollution but are also depleting worldwide. , The generation of green hydrogen via electrocatalytic water splitting, powered by renewable electricity, is a compelling approach, yet it is currently hampered by the reliance on costly noble metal electrocatalysts, such as Pt, for the cathodic hydrogen evolution reaction (HER). , MoS 2 , with its affordable cost and advantageous layered crystal structure, offers near-zero hydrogen adsorption energy (Δ G H* ) at its edges and defects, positioning it as a potential replacement for Pt in HER applications. − However, the practical catalytic activity of MoS 2 is often limited due to the inert nature of its basal plane toward HER, and its wide band gap hinders efficient charge transfer and electron mobility, thus constraining the catalytic process. , Strategic doping with heteroatoms has been recognized as an effective method to engineer MoS 2 by introducing defects and altering the host material’s intrinsic properties. , Among various dopants, selenium (Se) is particularly promising due to its high structural compatibility with MoS 2 , allowing for the creation of MoS x Se 2– x with a broad range of Se content. − Furthermore, Se’s lower electronegativity compared to sulfur can modulate the electronic structure of adjacent S atoms, potentially enhancing the catalytic performance of MoS 2 for HER applications.…”

FeS nanosheets assembled with 1T-MoS2 nanoflowers on iron foam for efficient overall water splitting

“…1T-MoS 2 usually shows higher conductivity and catalytic activity than that of the 2H phase. 5,6 Hence, 1T-MoS 2 based metallic sulfide heterostructures with particular morphologies and stability have been proposed as efficient strategies to modulate HER and OER activity. 7,8 Zhang et al prepared hierarchical 1T-MoS 2 /MoO 3 for efficient hydrogen evolution reaction.…”