Facile assembly of an efficient CoO_xwater oxidation electrocatalyst from Co-containing polyoxotitanate nanocages

Abstract

Cobalt-containing polyoxotitanates (TiCo) are excellent precursors for the simple and scalable preparation of Nocera-type CoOx water-oxidation electrocatalysts. The TiCo cages serve as a reservoir for cobalt ions in a titania matrix on fluoride-doped tin oxide electrodes, and form, in situ, the active CoOx catalyst for O2 evolution with high stability in phosphate buffer in pH neutral water.

How Does Substitutional Doping Affect Visible Light Absorption in a Series of Homodisperse Ti11 Polyoxotitanate Nanoparticles?

“…[4d, 13] The current series is derived from Ti 12 O 16 (OiPr) 16 by replacing one five-coordinated titanium atom and its isopropoxide ligandb yt he MX groups, and two of the m 2 Oa toms on the surface,b yt wo m 2 OiPr ligands,t hus maintaining the neutrality of the clusters. As shown in Figure1b, for TiMnCl,t he transition metal dopant is coordinated by one chloride ion through conventional exo-bonding and by four oxygen atomsf rom the TiOc ore, leadingt oadistorted square pyramid coordination geometry.T he bond lengthsa nd bond angles related to the transition metal dopants are listed in Ta ble 1, dimensions for Ti 12 are given in Ta ble S2 in the Supporting Information. As expected, the MÀXb ond length increases from Cl to Br to I, whereas the MX bond shortensf rom Mn to Fe to Co, both in agreement with the change in atomicradii.…”

“…They are Ti 11 (MnCl)O 14 (OiPr) 17 (1), Ti 11 (MnBr)O 14 (OiPr) 17 (2), Ti 11 (MnI)O 14 (OiPr) 17 (3 17 (7). The work is the first systematic study of al arge series of polyoxotitanate nanoparticles varying only by the natureo ft he dopant.F or clarity the complexesa re labeled below as TiMX with M = Mn, Fe, or Co and X = I, Br,o rC l. The parent complex Ti 12 O 16 (OiPr) 16 (8,l abeled as Ti 12 ), described previously, [5] is included for comparison. Ad istinction is made betweent he gap between the valence and conduction bands and between the HOMO-LUMO transition-energies involving orbitalsl ocated within the band gap.…”

Nanostructured Manganese Oxides as Highly Active Water Oxidation Catalysts: A Boost from Manganese Precursor Chemistry

“…[77][78][79] Interestingly, SSPs for the synthesis of conducting electrode surfaces for metal oxide water oxidation has already been utilized a while ago. [80,81] Herein, we present the facile synthesis of a versatile nanocrystalline manganese oxalate precursor by means of an inverse micellar approach. Thermal degradation of the oxalate precursor at different environments led to the desired mineral phases of nanostructured bixbyite (Mn 2 O 3 ), hausmannite (Mn 3 O 4 ), and manganosite (MnO) oxides (Scheme 1).…”

Water Oxidation at Electrodes Modified with Earth‐Abundant Transition‐Metal Catalysts

“…Since CoOx preparation controls performance, multiple processing techniques have been tested. [62][63][64][65] . Aging also has a strong effect on activity.…”