High surface area LaNiO3 electrodes for oxygen electrocatalysis in alkaline media

Abstract

Nickel containing perovskite type oxides have been reported within the most active materials for OER in alkaline media and also with good electrocatalysts properties for OOR. The increase of the bifunctional character of these materials is the subject of research in view of the need for alternatives to noble materials and to the paramount importance of electrode development for the next generation of regenerative fuel cells. The LaNiO 3 oxide was prepared by a self-combustion method using citric acid. The electrodes were prepared by coating a nickel foam support with an oxide suspension. Electrochemical characterization was carried out by Cyclic Voltammetry (CV) and Electrochemical Impedance (EI). The electrode's roughness factor has been estimated from the charging currents (i c ) recorded between -0.050 V and +0.050 V (Fig 1-a). From the linear variation between the i c vs sweep rate (sr), the double layer capacitance of 0.208±0.015 µF cm -2 was calculated (Fig 1-b). EI spectra were fitted to an equivalent circuit that rendered capacity values in agreement with those estimated by CV.The oxide coating roughness factor was estimated as 3463±250, representing a much higher value than those reported in the literature [1,2] for the same oxide. This enhancement of the electrodes roughness can be associated with the oxide preparation method associated with the use of Ni foam as the oxide support. AcknowledgementsThis work is partially financed by Fundação para a Ciência e Tecnologia (FCT), under contract nº PTDC/CTM/102545/2008.

Amorphous Ni0.75Fe0.25(OH)2‐Decorated Layered Double Perovskite Pr0.5Ba0.5CoO3‐δ for Highly Efficient and Stable Water Oxidation

“…Additional peaks are observed in the potential range of 1.3–1.5 V versus RHE for Ni 0.75 Fe 0.25 (OH) 2 decorated catalysts which is attributed to Ni (II)/Ni (III) redox pair. These peaks signify the formation of NiOOH as featured in the previous studies on nickel borate and nickel phosphate . This redox pair has been pointed out as the catalytic active sites for OER.…”

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

“…[204] Double perovskites have been described as highly active WOCs that are stable in alkaline solution, [205][206][207][208][209][210][211][212][213][214][215][216][217][218] although the need to include rare earths precludes their extended use. [209,210] For example, Ba-Sr-Co-Fe perovskite proved to be 10 times faster than IrO x . [211] Some of these perovskites exhibited structural changes during the water oxidation reaction, going from crystalline to amorphous, which could be due to conversion of the local structure from corner-sharing octahedral to edgesharing octahedral, associated with enhanced activity.…”

Perovskite Strontium Doped Rare Earth Manganites Nanocomposites and Their Photocatalytic Performances

“…These unusual properties may lead to use these materials in potential applications. The corner-shared octahedral BO 6 lattice site in these materials play very important role in transfer of oxygen and electrons easily and may lead to nonstoichiometry of oxygen [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. Moreover, the mixed valence states of the transition metal at B-site are also important term in such perovskite-type oxides, which affect their activity.…”

“…Moreover, the mixed valence states of the transition metal at B-site are also important term in such perovskite-type oxides, which affect their activity. Nevertheless a lot of applications depend on the A and B cations in the ABO 3 perovskites, such as electrocatalysts for O 2 evolution [8][9][10], catalysts [11,12], photo/electro-catalysts for hydrogen production and pollutants degradation [13][14][15][16][17][18][19] and electrode material used in fuel cells [13]. The synthesis of perovskite materials could be done using different methods such as solid state reaction [24][25][26][27][28], chemical co-precipitation [29][30][31][32][33], sol-gel [34][35][36][37][38].…”

“…The world Nanocomposites -Recent Evolutions of nanostructured photosensitizers, for example, plasmonic metal nanostructures, quantum dots, and carbon nanostructures engaged with the wide-bandgap in transition metal oxides that allow us to design a new visible-light active photocatalysts [4]. The implied mechanisms of the nanocomposite photocatalysts, for example, the charge separation inducing light and the visible-light photocatalytic reaction procedure in environmental treatment besides solar fuel generation fields, are also presented [10].…”