Ni_xCo_3‐xO₄ Nanoneedle Arrays Grown on Ni Foam as an Efficient Bifunctional Electrocatalyst for Full Water Splitting

Abstract

Developing highly active, stable and robust electrocatalysts based on earth-abundant elements for oxygen evolution reaction( OER) and hydrogen evolution reaction (HER) is important for many renewable energy conversion processes. Herein, Ni x Co 3-x O 4 nanoneedle arrays growno n3D porous nickel foam (NF) was synthesized as ab ifunctional electrocatalyst with OER and HER activity for full water splitting. Benefiting from the advantageous structure, thec omposite exhibits superior OER activity with an overpotential of 320 mV achieving the current density of 10 mA cm À2 .A ne xceptional HER activity is also acquired with an overpotential of 170 mV at the current density of 10 mA cm À2 .F urthermore, the catalyst also shows the superiora ctivity and stability for 20 hw hen used in the overall water splitting cell. Thus, the hierarchical 3D structure composed of the 1D nanoneedle structure in Ni x Co 3-x O 4 /NF represents an avenue to design and develop highly active and bifunctionalelectrocatalysts for promising energy conversion.Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

A Comparative Study of NiCo2O4, NiO, and Co3O4 Electrocatalysts Synthesized by a Facile Spray Pyrolysis For Electrochemical Water Oxidation

“…[29] Moreover, the oxide compounds combining nickel and cobalt (for instance, NiCo 2 O 4 ) as OER catalysts have also attracted increasing interests. [30][31][32][33][34] Fang et al showed that both the (111) and (110) facets in NiCo 2 O 4 nanosheets exhibited high OER activity. [30] Bao et al reported that mesoporous Ni x Co 3-x O 4 nanoneedle arrays exhibited a large electrochemically active area and showed a promising OER activity (320 mV at 10 mA cm −2 , Tafel slope of 38 mV dec −1 ).…”

“…[30] Bao et al reported that mesoporous Ni x Co 3-x O 4 nanoneedle arrays exhibited a large electrochemically active area and showed a promising OER activity (320 mV at 10 mA cm −2 , Tafel slope of 38 mV dec −1 ). [31] However, it is not straightforward to compare the OER performance of NiO, Co 3 O 4 , and NiCo 2 O 4 reported in literatures since these materials were synthesized by a large variety of methods and exhibited quite different surface morphologies and structural features. It is known that the OER activity of electrocatalysts depends on not only the material composition but also their surface morphology, micro-/nano-structural features, facets, synthesis methods and so on.…”

Ultrathin, Porous and Oxygen Vacancies‐Enriched Ag/WO3−x Heterostructures for Electrocatalytic Hydrogen Evolution

“…With the continually increasing crisis of energy crisis and environment pollution, renewable and clean energy sources have been widely concerned in recent years. Hydrogen, which can be produced from splitting of water, has been regarded as one of the most promising candidates for replacing fossil fuels in the future . Electrocatalytic water splitting is a sustainable and efficient approach for large‐scale hydrogen production .…”

Construction of Petal-Like Ag NWs@NiCoP with Three-Dimensional Core-Shell Structure for Overall Water Splitting

“…; Table S2: Comparison of the OER performances of Ag NWs@Ni 0.33 Co 0.67 P with the previously reported electrocatalysts at alkaline media; Table S3: Comparison of the HER performances of Ag NWs@Ni 0.33 Co 0.67 P with the previously reported electrocatalysts at alkaline media; Table S4: Comparison of overall water splitting performances of Ag NWs@Ni 0.33 Co 0.67 P with the previously reported electrocatalysts at alkaline media. References [ 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ] are cited in the Supplementary Materials.…”