Electrodeposition of Fe-Complexes on Oxide Surfaces for Efficient OER Catalysis

Abstract

Progress in non-covalent/self-assembled immobilization methods on (photo)electrode materials for molecular catalysts could broaden the scope of attainable systems. While covalent linkage (though considered more stable) necessitates functional groups introduced by means of often cumbersome synthetic procedures, non-covalent assemblies require sufficient propensity of the molecular unit for surface adsorption, thus set less rigorous pre-requisites. Herein, we report efficient electrodeposition (ED) of two Fe(III) complexes prepared with closely related NN’N pincer ligands yielding stable and active ad-layers for the electrocatalysis of the oxygen-evolving reaction (OER). The ED method is based on the utilization of a chloride precursor complex [FeIIICl2(NN’N)], which is dissolved in an organic electrolyte undergoes chloride/aqua ligand exchange upon addition of water. ED provides patchy distribution of a chloride-depleted catalyst layer on indium tin oxide (ITO) and fluorine-doped tin oxide (FTO) surfaces, which can be applied for long periods as OER electrocatalysts. Compared to drop-casting or layering of [FeIIICl2(NN’N)] with Nafion (a commonly used support for molecular electrocatalysts), the surface modification by ED is a material saving and efficient method to immobilize catalysts.

Porosification and Fe3+ Intercalation of Spent LiCoO2 as an Efficient Oxygen Evolution Electrocatalyst

“…It can be found that Fe 0.5 h-SLCO shows the most excellent TOF, which further proves the high activity of Fe 0.5 h-SLCO. This is determined by the combination of the increase in specific surface area after delithiation and the increase of Fe 3+ active sites after Fe 3+ intercalation, which are beneficial to OER. , Also, Fe 0.5 h-SLCO shows better OER activity, which is comparable to or even better than that of the recovered LiCoO 2 catalysts and synthesized LiCoO 2 -based catalysts reported in other literature (Table S2).…”

New Avenues to Chemical Space for Energy Materials by the Molecular Precursor Approach

“…[72] Most recently, electrodeposition is also adopted to fabricate molecular precursors directly on the substrate for electrochemical studies. [75,76] Apart from these traditional methods, several advanced techniques have been used to produce nanomaterials, namely, thermolysis, solvolysis, and drop-casting. [77][78][79] It is worth mentioning here that MOFs is a different class of polymeric inorganic material, which is also analogous to SSP.…”

Surface Modification of Electrocatalyst for Optimal Adsorption of Reactants in Oxygen Evolution Reaction

“…The electrocatalytic activities of stainless steel electrodes were studied in alkaline solution for OER. To evaluate catalytic performance, linear sweep voltammetry (LSV) is usually performed in alkaline solution by applying over the thermodynamic potential of OER (>1.23 V vs. RHE) [38][39][40]. Figure 4a shows the polarization curves for the OER of the CE, PE, 28%-HIE, and 28%-Si-HIE.…”