Amorphous molybdenum sulfide films as catalysts for electrochemical hydrogen production in water

Abstract

Amorphous molybdenum sulfide films are efficient hydrogen evolution catalysts in water. The films are prepared via simple electro-polymerization procedures and are characterized by XPS, electron microscopy and electronic absorption spectroscopy. Whereas the precatalysts could be MoS 3 or MoS 2 , the active form of the catalysts is identified as amorphous MoS 2 . Significant geometric current densities are achieved at low overpotentials (e.g., 15 mA cm À2 at h ¼ 200 mV) using these catalysts. The catalysis is compatible with a wide range of pHs (e.g., 0 to 13). The current efficiency for hydrogen production is quantitative. A 40 mV Tafel slope is observed, suggesting a rate-determining ion+atom step. The turnover frequency per active site is calculated. The amorphous molybdenum sulfide films are among the most active non-precious hydrogen evolution catalysts.

Sulfur-Depleted Monolayered Molybdenum Disulfide Nanocrystals for Superelectrochemical Hydrogen Evolution Reaction

“…This H 2 production efficiency is at least 1-2 orders of magnitude greater than in the cases of most of the other MoS 2 -based catalysts of similar mass (Table S2) (derived from the initial linear region of Figure 5a), which were also considerably larger than in the other cases (Table S2) Figure 5d; Figure S9; using efficient catalyst massof 2.39 µg ), which was > 1 order of magnitude greater than in the case of most of the other MoS 2 -based catalysts (Table S1). 1,3,4,6,7,11,14,16,31,32 …”

Two-dimensional inorganic analogues of graphene: transition metal dichalcogenides

“…Hinnemann et al [119] have shown that MoS 2 nanoparticles are good catalysts for the HER with an over potential as low as 0.1-0.2 V. Theoretical studies have revealed that the edge sites [120] and vacancies [121] in MoS 2 are catalytically active sites for HER. Enhanced photocatalytic and electrochemical HER activities have been achieved by increasing the surface area of or the density of active edge sites in the MoS 2 catalyst [122][123][124][125][126]. With the MoS 2 /graphene composite, electrocatalytic HER activity was further enhanced [127] due to a better electrical coupling to the electrode facilitated by graphene [128].…”

Mo2C nanoparticles embedded within bacterial cellulose-derived 3D N-doped carbon nanofiber networks for efficient hydrogen evolution

“…The turnover frequency of the Mo 2 C@N-CNF catalyst was estimated via previously reported methods. 35 Mo 2 C@N-CNFs achieve turnover frequencies of Figure S10), which is proportional to the effective electrochemical surface area. 37,38 The Mo 2 C@N-CNFs exhibit a high C dl of 11.34 mF cm − 2 at 0.22 V, which is slightly less than that of the high specific surface area vucan XC-72R carbon black-supported Pt catalyst (12.58 mF cm − 2 ) and comparable to those of many reported excellent non-precious HER catalysts, such as edge-terminated MoS 2 , 37 g-C 3 N 4 nanoribbon-graphene 39 and 3D CoSe 2 /carbon fiber felt.…”