Efficient tri-metallic oxides NiCo₂O₄/CuO for the oxygen evolution reaction

Abstract

In this study, a simple approach was used to produce nonprecious, earth abundant, stable and environmentally friendly NiCo2O4/CuO composites for the oxygen evolution reaction (OER) in alkaline media.

Incorporation of Cu/Ni in Ordered Mesoporous Co‐Based Spinels to Facilitate Oxygen Evolution and Reduction Reactions in Alkaline Media and Aprotic Li−O2 Batteries

“…This assumption supports the volcano trend in the overpotential (Figure S14) as a function of the Cu amount observed in present work. However, such trend might also be attributed to the change of the resistance and formation of more active intermediate species on the surface of the metal oxides, which is caused by Fe−Cu/Ni interactions [12,58] …”

“…However, such trend might also be attributed to the change of the resistance and formation of more active intermediate species on the surface of the metal oxides, which is caused by FeÀ Cu/Ni interactions. [12,58] The Tafel plots extracted from the LSV curves before and after 200 CVs are shown in Figure 3c,d and the values are stated in Table S3. The initial Tafel slope values are within the range of 50-56 mV dec À 1 for all the catalysts, except CuCo (71 mV dec À 1 ) implying slower kinetics of the reaction catalyzed by this oxide.…”

“…However, even though such Cu/Ni synergistic effect [25–32] has attracted great interest in catalysis and doping of Co 3 O 4 is known to increase the activity of the catalysts, the electrocatalytic properties of trimetallic CuNiCo oxides have not been thoroughly established. Only a limited number of studies include the examination of the electrocatalytic performance of CuNiCo oxides and the role of the Cu/Ni ratio in the systems [12,29,33,34] . Furthermore, hardly any work on ordered mesoporous mixed CuNiCo oxides can be found.…”

“…Spinel cobalt oxide (Co 2+ Co 3+ 2 O 4 ), with edge‐sharing CoO 6 octahedra (Co 3+ centered) interconnected by corner‐sharing CoO 4 tetrahedra (Co 2+ centered), can accommodate vacancies and lattice defects that potentially act as active sites to promote electrochemical reactions. [4] Experimental works coupled with density functional theory (DFT) calculations have shown that Co 3 O 4 ,[ 5 , 6 , 7 , 8 , 9 , 10 ] Cu‐doped Co oxides,[ 11 , 12 , 13 ] and bimetallic NiCo 2 O 4 [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ] are highly active and stable catalysts towards OER and/or ORR in alkaline media, emphasizing their potential use in the electrolyzers and fuel cells. Additionally, some published studies demonstrate that these materials can be active in other electrolytes, and show their potential application in the aprotic Li−O 2 batteries.…”

Enhanced Electrochemical Properties and OER Performances by Cu Substitution in NiCo2O4 Spinel Structure

“…In 1999, Tavares and his colleagues concluded that the substitution of Cu(II) in the NiCo 2 O 4 spinel lattice leads to significant changes in surface composition and oxygen evolution [ 18 ]. Meanwhile, Mugheri et al also reported OER performance on NiCo 2 O 4 /CuO electrode active material: 0.5 g of CuO on NiCo 2 O 4 showed a low starting potential of 1.46 V, and a current density of 10 mA cm −2 was achieved at an electrode potential of 230 mV, and the durability was maintained for 35 h [ 19 ]. On the other hand, due to the similar physical properties of Ni and Co, the preparation of nickel-cobalt bimetal oxide of NiCo 2 O 4 is relatively simple and a pure phase structure is easily formed.…”