Ni‐Assisted Low Temperature Synthesis of MoC_x with Enhanced HER Activity

Abstract

Here we report a novel one-pot approach to synthesize MoC catalysts at much lowered temperature for hydrogen evolution reaction (HER) in acidic solution. A room-temperature co-precipitation reaction among Ni , MoO and 2-methylimidazole in an aqueous solution produced a Mo-Ni-imidazole complex, which was used as the precursor to fabricate MoC . The morphological and chemical properties of the obtained MoC affected by calcination and other additive metal sources (like Fe, Co, Cu) were investigated in detail. We demonstrated that Ni-Mo alloying took place prior to MoC formation during heating, which catalyzed the crystallization of MoC at relatively low temperature. The MoC /Ni-650 catalyst exhibited a quite low overpotential of 172 mV at 20 mA cm . The high performance originates from the synergistic effect between MoC and Ni-Mo alloy, high ratio of Mo /Mo , as well as high electrochemically active surface area and low charge-transfer resistance. This work would open a new way to the design and fabrication of other transition-metal carbide catalysts.

Molybdenum Carbide/Carbon-Based Chitosan Hydrogel as an Effective Solar Water Evaporation Accelerator

“…The C 1s spectrum of MoCC displayed five peaks at 283.8, 284.3, 285.1, 285.6, and 288.2 eV, which were ascribed to C–Mo, CC, C–C, C–O, and CO, respectively (Figure S1b). The Mo 3d XPS spectrum (Figure g) contained two pair peaks, the main Mo 3+ with peaks at 229.0 and 232.45 eV (Mo 3d 5/2 and Mo 3d 3/2 ) and the Mo 6+ species from MoO 3 at 231.8 (Mo 3d 5/2 ) and 235.43 eV (Mo 3d 3/2 ) . Mo 3+ was designated as MoC, and Mo 3+ species were mainly because of the appearance of Mo vacancies .…”

“…30 The Mo 3d XPS spectrum (Figure 2g) contained two pair peaks, the main Mo 3+ with peaks at 229.0 and 232.45 eV (Mo 3d 5/2 and Mo 3d 3/2 ) and the Mo 6+ species from MoO 3 at 231.8 (Mo 3d 5/2 ) and 235.43 eV (Mo 3d 3/2 ). 31 Mo 3+ was designated as MoC, and Mo 3+ species were mainly because of the appearance of Mo vacancies. 32 Also, the existence of the Mo 6+ oxidation state could be on account of the surface-oxidized of MoCC in exposed air.…”

Surface and Interface Engineering: Molybdenum Carbide–Based Nanomaterials for Electrochemical Energy Conversion

“…Metal nanoparticles, such as Co, Ni, and Pt, [ 134–136 ] have been widely introduced to improve the electrochemical activity of catalysts for energy conversion. Metal nanoparticles existed in heterostructure hybrid demonstrates that the additional metal particles couple with the other metal/metal component and thus form abundant interfaces in the heterostructure.…”

“…Similar enhanced performances have also been investigated by the preparation of CNT/Mo x C, [131] the Mo x C/3D carbon foam, [132] the Mo x C/graphene, [133] and the Mo x C@N-carbon nanofibers structure. [128] Metal nanoparticles, such as Co, Ni, and Pt, [134][135][136] have been widely introduced to improve the electrochemical activity of catalysts for energy conversion. Metal nanoparticles existed in heterostructure hybrid demonstrates that the additional metal particles couple with the other metal/metal component and thus form abundant interfaces in the heterostructure.…”

Mesoporous Mn-Doped FeP: Facile Synthesis and Enhanced Electrocatalytic Activity for Hydrogen Evolution in a Wide pH Range

“…Tremendous efforts have been made to develop various Pt-free electrocatalysts in the past decades. For example, owing to comparable hydrogen adsorption free energy (Δ G H ) to Pt, transition metal sulfides, − carbides, − phosphides, − and nitrides − as potential HER electrocatalysts have been studied extensively. , Among them, transition metal phosphides (TMPs) like CoP, MoP, and Ni 2 P are particularly attractive since they possess high catalytic efficiency and good stability. − From the viewpoint of reserves and cost, FeP, a typical TMP, could be a promising HER catalyst for large-scale application, since element Fe is the most earth-abundant inexpensive transition metal . However, the relatively high overpotentials and sluggish reaction kinetics of FeP, as compared with Pt, may curtail its further development in mass hydrogen production.…”