β-FeOOH nanorod bundles with highly enhanced round-trip efficiency and extremely low overpotential for lithium-air batteries

Abstract

β-FeOOH nanorod (NR) catalysts prepared by ultrasonic-irradiated chemical synthesis enabled lithium-air cells to have high round-trip efficiency and extremely low overpotential as well as an outstanding rate capability. Good catalytic activities of the β-FeOOH NR bundle could be ascribed to its crystal structure, which consists of 2 × 2 tunnels formed by edge- and corner-sharing Fe(O,OH)6 octahedra as well as to its one-dimensional morphology, which makes the configured electrode highly porous, indicating that the -OOH-based catalyst can be a good substitute for oxide-base catalysts in lithium-air batteries. The ultrasonic-irradiated chemical synthesis suggested here may be a good solution to optimize the morphology of catalyst materials for maximum catalytic activity.

MnCo2O4 Nanowires Anchored on Reduced Graphene Oxide Sheets as Effective Bifunctional Catalysts for Li–O2 Battery Cathodes

“…Therefore, it is believed that anyi nsertion of Li + ions or conversion reactions of MCO NWs with Li + + ions are not involved under these Li-O 2 battery conditions;t his is also supported by the XRD results in Figure S8, which show that the crystal structure of the MnCo 2 O 4 was not changed after discharge ands ubsequent recharge processes. [23][24][25][26] (2) The network-likes tructure of the 1D MCO NWs could act as an efficient support for the 2D RGO sheetsa nd also improve electrical contact over the conductive RGO for facile electron transfer. This excellent performance with MCO@RGO catalysts could be attributed to their unique structural features as follows: (1) The large surface-to-volume ratio of the 1D MCO NWs could enablee lectrocatalytic activity to increase for higher lithium storage.…”

“…[21] However,t he low electronic conductivities of the MnCo 2 O 4 materials is as ignificant issue to be solved to further increase the ORR and OER activities. [23,24] The 1D catalysts could maintain their catalytic activities for many cycles,b ecause they enable the effective transport of electrons and Li + ions owing to their high surface-to-volumer atios. [8,9] Recently,t oe nhancec atalytic activity and long-term cyclability,s everal strategies were proposed.…”

“…For instance,t om inimize the Li + ion transport distance and enhancet he number of active sites, 1D nanostructured catalysts have been studied. [23,24] (2) The combination of 1D MCO NWs Ah ybrid composite system of MnCo 2 O 4 nanowires (MCO NWs) anchored on reduced graphene oxide (RGO) nanosheets was prepared as the bifunctional catalysto faL i-O 2 battery cathode. [25,26] In addition, to enhance the charge transfer rate, hybridizations with carbon materials such as graphene, [27] carbon nanotubes, [28] and Ketjenblack (KB) [29] have been reported.…”

Microwave–ultrasound assisted synthesis of β-FeOOH and its catalytic property in a photo-Fenton-like process

“…Ferric oxyhydroxides (goethite, akaganeite, lepidocrocite and feroxyhyte) as common constituents in soil and natural environment, with high surface area and quite stable chemical properties, have been widely used as adsorbents, ion exchangers, catalysts, sensors and electrode materials [1][2][3][4][5][6][7][8]. Goethite is the most studied oxyhydroxides because goethite is the most stable phase having the lowest Gibbs energy [9].…”

Silica-Coated and Bare Akaganeite Nanorods: Structural and Magnetic Properties

“…20 Akaganeite is interesting due to its structural, magnetic and catalytic properties, as well as for practical applications such as for the removal of pollutants, sorption, ion-exchange, lithium-air batteries. [22][23][24][25][26][27] Moreover, the β-FeOOH phase is important and widely used as a precursor in the 4 preparation of iron, hematite, maghemite and magnetite nanosized materials. 16,[28][29][30][31][32] Akaganeite is an antiferromagnetic material with a Néel temperature in the range of T N ≈ 240-299 K. 12,20,33 A substantial reduction of the Néel temperature, down to T N = 15 K, has been observed in amorphous β-FeOOH nanowires.…”