Iron-Doped Nickel Phosphide Nanosheet Arrays: An Efficient Bifunctional Electrocatalyst for Water Splitting

Tens of micrometers long metallic Ni submicrowires with a diameter of approximately 200 nm are prepared by a chemical reduction method under a magnetic field. Fe‐doped Ni2P nanosheets are then in situ grown on Ni submicrowires by a simple wet‐chemical reaction followed by a low‐temperature phosphorization process. The (Ni0.87Fe0.13)2P–Ni composite exhibits the highest catalytic activity toward oxygen evolution reaction in alkaline solution among all the as‐prepared (Ni1−xFex)2P–Ni catalysts, delivering a current density of 10 mA cm−2 at an overpotential of only 257 mV and keeping high stability over 10 h electrolysis. These exceptional activities are attributed to the unique structure combining metallic Ni submicrowires as good electronically conductive substrate and the in situ grown Fe‐doped Ni2P nanosheets. Specifically, Fe incorporation leads to strong electron interactions between Ni, Fe, and P, fast reaction kinetics, small charge‐transfer resistance, and a large electrochemical surface area, which are responsible for the excellent catalytic performance.

Section: Resultsmentioning

confidence: 95%

Iron‐Doped Nickel Phosphide Nanosheets In Situ Grown on Nickel Submicrowires as Efficient Electrocatalysts for Oxygen Evolution Reaction

Chen

Sheng

et al. 2018

“…Moreover, through further comparison with some other reported Ni‐based HER electrocatalysts, Ni‐S−P NRs/NF also exhibits preferable or comparable performance in 1.0 M KOH solution. Such as NiS@Ni 2 P 2 S 6 /NF (η 10 =140 mV), porous Ni−Fe−P/NF (η 10 =142 mV), NiCo 2 S 4 NWs/NF (η 10 =210 mV), N doped Ni 3 S 2 NSs/NF (η 10 =155 mV), N doped Ni 3 S 2 /VS 2 NSs‐NF (η 10 =151 mV), MoP/Ni 2 P/NF (η 100 =191 mV), N 2 P NSAs/NF (η 10 =191 mV) and so on.…”

Section: Resultsmentioning

confidence: 99%

One‐step Synthesis of Self‐standing Ni₃S₂/Ni₂P Heteronanorods on Nickel Foam for Efficient Electrocatalytic Hydrogen Evolution over a Wide pH Range

Zhou

et al. 2018

The development of efficient, stable and low‐cost electrocatalysts for hydrogen evolution reaction (HER) through a facile strategy is undoubtedly vital to realize sustainable production of H2 in water splitting but still challenging. Herein, we present a one‐step approach, a simultaneous phosphorization and sulfurization thermal treatment of NF at low temperature, to direct grow Ni‐S−P heteronanorod arrays consisting of Ni3S2 and Ni2P on nickel foam (Ni‐S−P NRs/NF). Due to the direct growth, one‐dimensional structure and good conductivity of the catalyst hybrid, as well as the synergistic effect between Ni3S2 and Ni2P, the resultant Ni‐S−P NRs/NF exhibited excellent HER electrocatalytic activity over a wide pH range. Ni‐S−P NRs/NF shows an overpotential of 180, 148 and 292 mV to reach the current density of 100 mA cm−2 in 1.0 M KOH, 0.5 M H2SO4 and 1.0 M PBS solution, respectively. DFT theoretical calculations was further confirmed that the superior pH‐universal HER activity of Ni‐S−P NRs/NF is originated from the thermo‐neutral hydrogen adsorption free energy and the enhanced adsorption of water molecular by the Ni3S2/Ni2P heterostructure.

“…Hu and co‐workers reported a bifunctional catalyst of Ni 2 P nanoparticles with excellent electrochemical activity for OER and HER . However, it is also noted that the catalytic activity of monometallic Ni 2 P is limited to the few types of composition and structure . On the other hand, vanadium (V) is a kind of rich element in the earth‘s crust .…”

Section: Introductionmentioning

confidence: 99%

Vanadium Doped Nickel Phosphide Nanosheets Self‐Assembled Microspheres as a High‐Efficiency Oxygen Evolution Catalyst

Jiang

Miao

et al. 2019

Recently, much attention has been paid to the low-cost, highefficiency and stable non-precious metal catalysts for oxygen evolution reaction (OER). In this work, vanadium (V)-doped nickel phosphide (Ni 2 P) nanosheets self-assembled microspheres supported on nickel foam (Ni 1 V 1 P NSs/NF) were synthesized as a novel OER catalyst by combined processes of hydrothermal method and low-temperature phosphorization. The synthesized Ni 1 V 1 P NSs/NF material shows excellent catalytic activity due to its interconnected three-dimensional (3D) structure and synergistic effect between nickel and vanadium.When used as a catalyst electrode for OER, the synthesized Ni 1 V 1 P NSs/NF exhibits excellent electrocatalytic activity, reaching a current density of 50 mA cm À 2 at the low overpotential of 250 mV in 1.0 M KOH. This material also shows superior electrochemical stability with negligible decay of the activity after continual measurement for 15 h at 50 and 100 mA cm À 2 in 1.0 M KOH, respectively. This work provides a valuable method to synthesize efficient OER catalysts by doping valence-variable metal ions and designing distinctive 3D structure.