In situ electrochemical construction of Co/CoP crystalline-amorphous hetero-phase catalysts for highly efficient electrocatalytic hydrogen evolution

Abstract

Herein we develop a facile, one-step electrochemical approach for in situ constructing of Co/CoP crystalline-amorphous hetero-phase catalyst towards hydrogen evolution reaction (HER). The unique catalyst demonstrates low overpotential of 83...

Strongly Coupled Heterostructured CoP/MoO2 as an Advanced Electrocatalyst for Urea-Assisted Water Electrolysis

“…The XPS full spectrum of CoP/MoO 2 /NF (Figure (b)) demonstrates the presence of Co, P, Mo, and O elements. As shown in Figure (c), the high-resolution spectra of Co 2p display two distinct peaks centered around 798.1 and 782.1 eV, corresponding to Co 2p 1/2 and Co 2p 3/2 , respectively. ,, The appearance of a peak at 778.6 eV reveals the presence of the Co–P bond, originating from the CoP species. , As shown in Figure (d), the peak observed at 129.9 eV belongs to P 2p, while the peak at 134.1 eV can be attributed to the P–O bond resulting from the oxidation of phosphorus on the surface of CoP/MoO 2 /NF . In Mo 3d spectra (Figure (e)), peaks at binding energies 230.8 and 232.5 eV can be assigned to Mo 3d 5/2 and Mo 3d 3/2 of Mo 4+ in CoP/MoO 2 /NF, respectively. , Additionally, there are two additional peaks corresponding to Mo 3d 5/2 and Mo 3d 3/2 of Mo 6+ , indicating that a part of MoO 2 is oxidized by ambient air .…”

“…23,33,34 The appearance of a peak at 778.6 eV reveals the presence of the Co−P bond, originating from the CoP species. 27,35 As shown in Figure 1(d), the peak observed at 129.9 eV belongs to P 2p, while the peak at 134.1 eV can be attributed to the P−O bond resulting from the oxidation of phosphorus on the surface of CoP/MoO 2 /NF. 36 In Mo 3d spectra (Figure 1(e)), peaks at binding energies 230.8 and 232.5 eV can be assigned to Mo 3d 5/2 and Mo 3d 3/2 of Mo 4+ in CoP/MoO 2 /NF, respectively.…”

“…On the one hand, transition metal phosphides (TMPs), particularly cobalt phosphide (CoP), have attracted significant attention in electrolytic water splitting because of their low cost, high electrical conductivity, and chemical stability, in addition to their more sustainable nature compared to expensive and scarce noble metals. − Nevertheless, one challenge in using CoP for water electrolysis is its high cell voltage, which is attributed to sluggish kinetics during the HER and OER processes . Accordingly, various strategies have been employed to enhance the HER or OER activity of CoP, such as doping with metal or nonmetal elements (e.g., Fe, Mo, S), vacancy engineering, tuning the stoichiometric ratio of P and Co, and constructing amorphous structures. − Despite significant progress in research, modified CoP-based catalysts still exhibit a high driving voltage and poor durability for water splitting. Moreover, few investigations have been devoted to the use of the CoP catalyst in replacing the sluggish OER with the UOR process.…”

High surface activity of Fe-doped NiCoP for the hydrogen evolution reaction

“…Transition metal phosphates (TMPs), such as CoP, Ni 2 P and FeP, have shown comparable performance to Pt as HER electrocatalysts in a wide pH range due to their unique electronic properties. [8][9][10][11][12] However, TMPs exhibit weak conductivity and insufficient catalytic sites, which hinders the effective adsorption of intermediate states for rapid electrochemical reaction kinetics. The electron delocalization of metal atoms is confined by P atoms, leading to weakened catalytic activity in HER processes.…”