Rationally designed Water-Insertable Layered Oxides with Synergistic Effect of Transition-Metal Elements for High-Performance Oxygen Evolution Reaction

Abstract

Oxygen evolution reaction (OER) is a key step in many energy conversion and storage processes. Here, by rationally adding an appropriate amount of Mn into the lattice of a layered Na x CoO 2 parent oxide, high solubility of iron into the Na x CoO 2 oxide lattice is realized without the use of an extremely air-sensitive Na 2 O 2 raw material, and the synergy created between the Co and Fe can boost the catalytic activity of the layered oxide for OER. Moreover, the water intercalation capability of the layered oxides can be utilized to make the oxide resemble mixed metal hydroxides, which will also bring a beneficial effect for OER. As a result, the as-developed Na 0.67 Mn 0.5 Co 0.3 Fe 0.2 O 2 (CF-32) layered oxide with an optimal Co/Fe ratio and water intercalation shows high OER performance in alkaline media, overperforming the benchmark IrO 2 catalyst. In 0.1 M KOH solution, the novel catalyst shows 0.39 V overpotential at 10 mA cm −2 and favorable stability. The excellent OER performance of CF-32 is due to the synergistic effect of transition-metal elements (Co and Fe) and water intercalation, leading to little charge transfer resistance, large amounts of exposed catalytic active sites, plenty of surface high oxidation state O 2 2− /O − oxygen species, and hydroxide-rich surface. The facile synthesis and high OER performance of CF-32 enriches the non-noble metal family of OER catalysts and boosts the practical application of non-noble metal catalysts.

Nonmetallic Active Sites on Nickel Phosphide in Oxygen Evolution Reaction

“…On the other hand, the P atoms carries more positive charge, making it easier to adsorb OH. It has been reported that the synergistic effect between atoms can promote charge transfer and accelerate the catalytic reaction [ 67 , 75 , 76 ]. Therefore, the synergistic action of P and Ni atoms can promote the charge transfer between atoms, and makes P atoms the active sites in OER.…”

Amorphous CoOx-Decorated Crystalline RuO2 Nanosheets as Bifunctional Catalysts for Boosting Overall Water Splitting at Large Current Density

“…Furthermore, multimetal oxide is also favorable to enhance catalytic activity because the diversity of metal compositions can offer more possible approaches to design catalysts . The synergy between different components can adjust the electronic structure to achieve ideal adsorption/desorption sites to enhance the catalytic activity for OER and/or HER. , Cui et al prepared ultrasmall NiFeO x nanoparticles for OWS through lithium-induced conversion, which can attain 10 mA cm –2 at 1.51 V . Wei et al fabricated CoFe 2 O 4 nanosheets via surface-defect engineering strategy, which exhibited excellent OWS activity with 1.53 V to reach 10 mA cm –2 .…”

“…18 The synergy between different components can adjust the electronic structure to achieve ideal adsorption/desorption sites to enhance the catalytic activity for OER and/or HER. 19,20 Cui et al prepared ultrasmall NiFeO x nanoparticles for OWS through lithium-induced conversion, which can attain 10 mA cm −2 at 1.51 V. 21 nanosheets via surface-defect engineering strategy, which exhibited excellent OWS activity with 1.53 V to reach 10 mA cm −2 . 22 Although these works exhibited highly efficient catalytic activity for water electrolysis, they only focus on small current density.…”

Tuning Reconstruction Level of Precatalysts to Design Advanced Oxygen Evolution Electrocatalysts

“…Particularly, first-row transition metal-based materials, such as oxyhydroxides, oxides (e.g., spinel oxides and perovskite oxides), and metal phosphides/chalcogenides reportedly show outstanding OER performance, given their flexible electronic structure and enriched active sites [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. Notably, the electrocatalytic activities of many reported compounds based on nonprecious transition metals are even superior to those of noble-metal-based catalysts [ 23 , 42 , 43 , 44 , 45 ].…”