Comparison Study toward the Influence of the Second Metals Doping on the Oxygen Evolution Activity of Cobalt Nitrides

Abstract

We report on the development of secondary metals doped Co5.47N nanosheets [donated as CoM(3:1)-N (M = Fe, Ni, Mn, and Zn; 3:1 is the molar ratio of Co to M)] as nonprecious metal OER catalysts. Electrochemical test results show that the Fe-doped CoFe(3:1)-N possesses superior OER activity (only need an overpotential of 200 mV to drive 10 mA cm–2) and long-term durability in 1.0 M KOH which outperform those of RuO2. X-ray photoelectron spectroscopy characterization results reveal that the Fe doping into crystal texture has led to the largest positive shift (∼1.2 eV) in binding energy of Co 2p compared to Ni, Mn, and Zn; the Lewis acid effect of Fe3+ can boost the formation of more Co4+ OER active sites. Our finding discloses the enhancing mechanism of OER on second metals-doped bimetallic nitrides and meanwhile affords a new concept toward exploring and designing high-efficiency non-noble metal OER electrocatalysts.

Electrochemical behavior of a Ni3N OER precatalyst in Fe-purified alkaline media: the impact of self-oxidation and Fe incorporation

“…[2][3][4][5][6][7][8][9] Except for some special cases (e.g., FeP, Ni 3 Se 2 , and Ni 3 Te 2 ), [10][11][12] most TM X-ides are self-oxidized into their TM oxide/(oxy)hydroxide counterparts under potentials at which OER occurs. [13][14][15][16][17][18][19][20] As the newly-formed TM oxide/(oxy)hydroxide species are more favorable electrocatalytic active sites for the OER than the initial TM X-ide, these easily oxidizable TM X-ides are sometimes described as "precatalysts". 17 Moreover, the TM oxides/(oxy)hydroxides derived from these TM X-ides are apt to exhibit higher OER activities than the corresponding, directly synthesized TM oxides/(oxy)hydroxides.…”

Mesoporous Ternary Nitrides of Earth-Abundant Metals as Oxygen Evolution Electrocatalyst

“…One approach, the introduction of an additional transition metal element, allows tuning of the electronic structure and improvement of the precipitation energies compared to single-metal materials [ 13 ] due to the synergistic effect of a mixed metal system. For example, the incorporation of Fe into CoN has been shown to improve the catalytic performance compared to pure cobalt nitride [ 14 , 15 ]. As another approach, the formation of nanostructured TMNs can provide abundant accessible active sites, high infiltration capacity, and large contact area [ 16 ].…”

Non‐3d Metal Modulation of a 2D Ni–Co Heterostructure Array as Multifunctional Electrocatalyst for Portable Overall Water Splitting

“…The broad peak at 826 cm −1 corresponds to Mo–N species, which may be induced by Ni (Figure 2g). Figure 2h shows the XRD patterns of Mo‐NiCo 2 O 4 /Co 5.47 N, where all the diffraction peaks can be indexed to NiCo 2 O 4 (JCPDS 73‐1704), and Co 5.47 N (JCPDS 41‐0943) . It is worth noting that no impurity phases, such as Mo‐based oxides and/or nitrides, were observed in the XRD patterns, indicating the successful introduction of Mo species into NiCo 2 O 4 /Co 5.47 N heterostructure.…”