Self-Supporting NiFe Layered Double Hydroxide “Nanoflower” Cluster Anode Electrode for an Efficient Alkaline Anion Exchange Membrane Water Electrolyzer

Abstract

The development of an efficient and durable oxygen evolution reaction (OER) electrode is needed to solve the bottleneck in the application of an anion exchange membrane water electrolyzer (AEMWE). In this work, the self-supporting NiFe layered double hydroxides (NiFe LDHs) “nanoflower” cluster OER electrode directly grown on the surface of nickel fiber felt (Ni fiber) was synthesized by a one-step impregnation at ambient pressure and temperature. The self-supporting NiFe LDHs/Ni fiber electrode showed excellent activity and stability in a three-electrode system and as the anode of AEMWE. In a three-electrode system, the NiFe LDHs/Ni fiber electrode showed excellent OER performance with an overpotential of 208 mV at a current density of 10 mA cm−2 in 1 M KOH. The NiFe LDHs/Ni fiber electrode was used as the anode of the AEMWE, showing high cell performance with a current density of 0.5 A cm−2 at 1.68 V and a stability test for 200 h in 1 M KOH at 70 °C. The electrocatalytic performance of NiFe LDHs/Ni fiber electrode is due to the special morphological structure of “nanoflower” cluster petals stretching outward to produce the “tip effect,” which is beneficial for the exposure of active sites at the edge and mass transfer under high current density. The experimental results show that the NiFe LDHs/Ni fiber electrode synthesized by the one-step impregnation method has the advantages of good activity and low cost, and it is promising for industrial application.

Regulating Reaction Intermediate Adsorption of Co0.5NiS2–Ni3S2 Nanorods for Efficient Urea Electrolysis

“…Additionally, in order to enable the efficient and stable operation of catalysts at large current densities, the catalyst must be able to withstand intense reactant transport and product escape. Constructing self-supporting hierarchical nanostructures with abundant pores and high specific surface area is an effective approach that could facilitate the transport of reactants and products. , Meanwhile, the stable binding between the active material and the substrate can effectively avoid their aggregation and shedding, thus improving the mechanical stability of catalysts. , In our previous work, the Ni-modified Co 2 VO 4 heterostructure with mesoporous nanosheets self-supporting on nickel foam (NF) was prepared via a hydrothermal method, which can deliver ±500 mA cm –2 at a relatively low potential of 1.38 V and −267 mV for the UOR and HER, and it can operate stably over 140 h at this current density …”

Hydrogen production by traditional and novel alkaline water electrolysis on nickel or iron based electrocatalysts

“…Guo et al developed a nanoflower cluster-like NiFe-LDH structure (NiFe-LDHs/Ni fiber) on the nickel fiber felt through a single-step impregnation process in FeCl 2 and NiCl 2 mixture solution. 103 This structure, due to its huge electrochemical specific surface area and excellent mass transfer effect, demonstrated a low overpotential of 208 mV (@ 10 mA cm À2 ) and a Tafel slope of 50 mV dec À1 in 1 M KOH when used as the OER electrode. Additionally, when employed as an anode material for anion exchange membrane water electrolysis (AEMWE), the NiFe-LDH/Ni fiber could be used for 200 hours at 0.5 A cm À2 (1 M KOH, 70 1C, as shown in Fig.…”

Key components and design strategy of the membrane electrode assembly for alkaline water electrolysis

“…The OER process in alkaline electrolytes involves the consumption of OH À in multiple steps. The widely recognized OER mechanisms can be summarized as the , 27 3, 28 4, 29 5, 30 6, 31 7, 32 8, 33 9, 34 10, 35 11, 36 12, 37 13, 38 14, 39 15, 40 16, 41 17, 42 18, 43 19, 44 20, 45 21, 46 22, 47 23, 48 24, 49 25, 50 26, 51 27, 52 28, 53 29, 54 30, 55 31, 56 32, 57 33, 58 34, 59 35, 60 36, 61 37, 62 38, 63 39, 64 40, 65 41. 66 (b): 1, 67 2, 32 3, 33 4, 35 5, 48 6, 68 7, 69 8, 70 9, 39 10, 62 11, 71 12, 41 13, 72 14, 53 15,…”

“…(c) Degradation rates during continuous long-term durability testing of the reported alkaline water electrolysis employing PGM-free electrocatalysts. References for data points for (a): 1,26 2, 27 3, 28 4,29 5,30 6,31 7,32 8,33 9,34 10,35 11,36 12,37 13,38 14,39 15,40 16,41 17,42 18,43 19,44 20,45 21,46 22,47 23,48 24,49 25,50 26,51 27,52 28,53 29,54 30,55 31,56 32,57 33,58 34,59 35,60 36,61 37,62 38,63 39,64 40,65 41. 66 (b): 1, 67 2,32 3, 33 4,35 5,48 6,68 7,69 8,70 9,39 10,62 11,71 12,41 13,72 14,53<...…”