Ultrathin Porous NiFeV Ternary Layer Hydroxide Nanosheets as a Highly Efficient Bifunctional Electrocatalyst for Overall Water Splitting

Abstract

Herein, the hydrothermal synthesis of porous ultrathin ternary NiFeV layer double hydroxides (LDHs) nanosheets grown on Nickel foam (NF) substrate as a highly efficient electrode toward overall water splitting in alkaline media is reported. The lateral size of the nanosheets is about a few hundreds of nanometers with the thickness of ≈10 nm. Among all molar ratios investigated, the Ni Fe V -LDHs/NF electrode depicts the optimized performance. It displays an excellent catalytic activity with a modest overpotential of 231 mV for the oxygen evolution reaction (OER) and 125 mV for the hydrogen evolution reaction (HER) in 1.0 m KOH electrolyte. Its exceptional activity is further shown in its small Tafel slope of 39.4 and 62.0 mV dec for OER and HER, respectively. More importantly, remarkable durability and stability are also observed. When used for overall water splitting, the Ni Fe V -LDHs/NF electrodes require a voltage of only 1.591 V to reach 10 mA cm in alkaline solution. These outstanding performances are mainly attributed to the synergistic effect of the ternary metal system that boosts the intrinsic catalytic activity and active surface area. This work explores a promising way to achieve the optimal inexpensive Ni-based hydroxide electrocatalyst for overall water splitting.

Ultrathin Amorphous Iron–Nickel Boride Nanosheets for Highly Efficient Electrocatalytic Oxygen Production

“…[37,54] The weight difference between the modified NF and the blank NF was divided by the surface area, and the catalyst loading was found to be approximately 1.0 mg cm À2 . Afterwards, they were ultrasonicated in a3 m HCl solution for 45 min, followed by washing with water and ethanol several times to ensure the surface was well cleaned before use.…”

A Facile Synthesis of FeCo Nanoparticles Encapsulated in Hierarchical N‐Doped Carbon Nanotube/Nanofiber Hybrids for Overall Water Splitting

“…This is one of the best reported activity for OER on glassy carbon electrode (GCE) under steady state conditions . However, the loss in activity after 9,000 seconds might be due to the blockage of the small exposed surface area of GCE (0.07 cm 2 ) by the released bubbles of O 2 . To further investigate the stability of the catalyst, another chronopotentiometric experiment was performed on Ni foam by depositing the same amount of sample i. e. 0.14 mg cm −2 .…”

“…Hence, cost effective non‐noble metal based electrocatalysts that may efficiently be used as bifunctional catalysts (i. e. for both OER and HER) and accelerate the charge transfer process by lowering the over‐potential for water splitting are desired . In addition, the use of a bifunctional catalyst simplifies the electrochemical set‐up by using the same catalyst at both electrodes which should ideally work efficiently under the same pH and, thus, reducing the cost …”

Constructing Multifunctional Heterostructure of Fe2O3@Ni3Se4 Nanotubes

“…X‐ray photoelectron spectroscopy (XPS) was further used to investigate the valance states of Fe 2 O 3 @Ni 3 Se 4 nanotubes with I Ni:Fe = 1:10 (Figure S4b–d, Supporting Information). The Fe 2p XPS spectrum (Figure S4b, Supporting Information) reveals two peaks at the binding energy of 710.8 and 724.2 eV, which correspond to Fe 2p 3/2 and Fe 2p 1/2 as the characteristic peaks of Fe 3+ . As shown in the Ni 2p region (Figure S4c, Supporting Information), the main peaks of Ni 2p 3/2 and 2p 1/2 are clearly affirmed at 854.6 and 872.1 eV, respectively.…”