Tunable 3D hierarchical Ni₃S₂superstructures as efficient and stable bifunctional electrocatalysts for both H₂and O₂generation

Abstract

3D hierarchical Ni3S2superstructures arein situgrown on nickel foam to build self-supported electrode for overall water splitting.

A highly active and durable electrocatalyst for large current density hydrogen evolution reaction

“…This comparison indicates that the electrochemical active materials in our catalyst are dominantly coaxial MoS 2 / Ni 3 S 2 NWs. Note that these values are much smaller than those of the reported MoS 2 /Ni 3 S 2 -NF materials (187 and 274, 110 and 200, 98 and 191 mV) [21][22][23] and many other NF-based catalysts (Table S1 online), including Ni 3 S 2 (135 and 225 mV) [31], Ni 2 P-Ni 3 S 2 heteronanoflake arrays (80 and~160 mV) [32] and Ni 2(1-x) Mo 2x P (72 and 162 mV) [27]. Moreover, the overpotential for current density of 100 mA cm À2 is close to that of Pt/C-NF (110 mV).…”

“…Our MoS 2 / Ni 3 S 2 NW-NF has a Tafel slope of 58.9 mV dec -1 , indicating that the HER process follows the Volmer-Heyrovsky mechanism, where the electrochemical desorption of hydrogen is the ratedetermining step. This value is also lower than many NF-based catalysts, like MoS 2 /Ni 3 S 2 [21][22][23], Ni 3 S 2 [31], Ni 2 P-Ni 3 S 2 [32] and Ni@Co-Ni-P [33], except for Ni 2(1-x) Mo 2x P [27] and FeP/Ni 2 P [28] ( Fig. 3c and Table S1 (online)).…”

Fe‐Doped Ni3S2 Nanowires with Surface‐Restricted Oxidation Toward High‐Current‐Density Overall Water Splitting

“…The Raman spectra in Figure further verified the successful synthesis of Ni 3 S 2 . For undoped Ni 3 S 2 , the characteristic Raman peaks at 193.6, 216.4, 301.7, and 341.8 cm −1 can be assigned to one A 1 and three E vibrational modes of Ni 3 S 2 , which are well matched with the corresponding heazlewoodite phase of Ni 3 S 2 . For Fe 13.7% ‐Ni 3 S 2 , the peaks are all shifted to a lower wavenumber compared to undoped Ni 3 S 2 , revealing the state of Ni−S bonds was changed by Fe ions doped into Ni 3 S 2 lattices.…”

“…[6][7][8][9] Among these catalysts, nickel-based compounds, e. g. nickel sulfides, have unique configuration and high conductivity, of which abundant NiÀ S and NiÀ Ni bonds can facilitate the production of the intermediate (OOH*) for OER and the adsorbed hydrogen (H*) converted to H 2 for HER, therefore, are employed as promising water splitting electrocatalysts. [10][11][12][13][14][15][16][17] Nickel sulfide with suitable element doping can modulate its electronic and surface structure, hence, significantly enhancing the electrocatalytic performance for OER and (or) HER. Zn, [18] V, [19] Sn, [20] N, [21] Mo, [22] and Fe [23][24][25][26][27][28] elements have been doped in nickel sulfide lattices for promoted OER, HER or overall water splitting electrocatalysis.…”

Three dimensional Ni3S2 nanorod arrays as multifunctional electrodes for electrochemical energy storage and conversion applications

“…[38][39][40][41] In recent years, Ni 3 S 2 , a typical nickel sulde with a high theoretical capacity of 2412 F g À1 , has been reported to demonstrate outstanding electrochemical performances for supercapacitors and H 2 evolution due to its low cost, good conductivity, higher electrochemical activities and environmental friendliness. [42][43][44] Li et al synthesized Ni 3 S 2 nanoparticles by simple mechanical alloying as the electrode for a supercapacitor. 45 The supercapacitor demonstrated a specic capacitance of 911 F g À1 at 0.5 A g À1 .…”