An Oxygenophilic Atomic Dispersed FeNC Catalyst for Lean‐Oxygen Seawater Batteries

Abstract

A constant energy supply is crucial for the exploration of deep‐sea extreme environments, and a self‐powered energy conversion device is ideal for this situation. Dissolved‐oxygen seawater batteries (SWBs) that generate electricity by reducing the dissolved oxygen are promising candidates but the ultralow oxygen concentration in deep sea limits the reaction kinetics. As a result, oxygenophilic electrocatalysts for lean‐oxygen conditions are urgently needed. A microwave heating method is reported that achieves the ultrafast synthesis of atomic dispersed FeNC catalyst (FeNgraphene (G)/carbon nanotube (CNT)), which possesses high activity and strong oxygenophilic interface between graphene and CNTs. DFT calculations and experimental results both show that the high oxygenophilicity is due to the double‐adsorption sites on the G/CNT interface, and the high activity FeN4 active sites is caused by the charge separation. FeNG/CNT catalysts have an outstanding oxygen reduction reaction (ORR) performance in both O2‐saturated alkaline medium and neutral seawater with half‐wave potentials (E1/2) of 0.929 and 0.704 V, respectively, far better than commercial Pt/C. A SWB shows excellent performance in lean‐oxygen seawater (≈0.4 mg L−1), with a discharge voltage of 1.18 V at 10 mA cm−2. These results suggest a critical role for oxygenophilic catalyst specifically for SWBs under lean‐oxygen conditions.

Doping‐Induced Electronic/Ionic Engineering to Optimize the Redox Kinetics for Potassium Storage: A Case Study of Ni‐Doped CoSe2

“…Owing to the incorporation of Ni atoms, the heterointerface results in an optimized effect on the reshaping of the electronic structure of the electrode materials, suggesting a more conductive characteristic of the K 2 Se/Co(Ni 10%). [ 40 ] The calculated DOS analysis and corresponding charge density difference of the K 2 Se/Co(Ni 50%) interface are shown in Figure S24 in the Supporting Information. Conclusively, the controllable electronic engineering not only facilitates the potassium intercalation, but also drives the conversion reaction during the electrochemical process, ultimately leading to an enhancement in the K + storage capacity.…”

Tuning Zn‐Ion Solvation Chemistry with Chelating Ligands toward Stable Aqueous Zn Anodes

“…Therefore, using this functional ligand in the electrolyte improves the cycling performance at high areal capacities because it inhibits corrosion and dendrite growth. Even in a harsh electrolyte, such as a seawater-based ZnSO 4 electrolyte (Table S2, Figures S50 and S51, Supporting Information), [53] the EDTA-Zn complex still gives the full cell remarkable corrosion resistance and reversibility. Hence, the high stability of the Zn anode with the EDTA-based electrolyte has been proved to give a better performance in full cells in not only a traditional electrolyte but in seawater.…”

Research progress of asymmetrically coordinated single-atom catalysts for electrocatalytic reactions

“…29,30 In recent years, many catalysts with M-N 4 active sites in a symmetric coordination environment have been reported. [31][32][33][34] However, with the deepening of the research, researchers found that compared with the relatively traditional M-N 4 symmetric structure, the coordination environment and electronic structure of the catalyst can be exibly designed through a reasonable adjustment of the asymmetric coordination structure. Asymmetric coordination approach brings satisfactory catalytic performance to M-N-C catalysts.…”