Generalizable, Electroless, Template-Assisted Synthesis and Electrocatalytic Mechanistic Understanding of Perovskite LaNiO₃ Nanorods as Viable, Supportless Oxygen Evolution Reaction Catalysts in Alkaline Media

Abstract

The oxygen evolution reaction (OER) is a key reaction for water electrolysis cells and air-powered battery applications. However, conventional metal oxide catalysts, used for high-performing OER, tend to incorporate comparatively expensive and less abundant precious metals such as Ru and Ir, and, moreover, suffer from poor stability. To attempt to mitigate for all of these issues, we have prepared one-dimensional (1D) OER-active perovskite nanorods using a unique, simple, generalizable, and robust method. Significantly, our work demonstrates the feasibility of a novel electroless, seedless, surfactant-free, wet solution-based protocol for fabricating "high aspect ratio" LaNiO and LaMnO nanostructures. As the main focus of our demonstration of principle, we prepared as-synthesized LaNiO rods and correlated the various temperatures at which these materials were annealed with their resulting OER performance. We observed generally better OER performance for samples prepared with lower annealing temperatures. Specifically, when annealed at 600 °C, in the absence of a conventional conductive carbon support, our as-synthesized LaNiO rods not only evinced (i) a reasonable level of activity toward OER but also displayed (ii) an improved stability, as demonstrated by chronoamperometric measurements, especially when compared with a control sample of commercially available (and more expensive) RuO.

Assemblage of Perovskite LaNiO3 Connected With In Situ Grown Nitrogen‐Doped Carbon Nanotubes as High‐Performance Electrocatalyst for Oxygen Evolution Reaction

“…In contrast, the LaNiO 3 * (Figure b) shows an irregular morphology with the larger size of 100–300 nm. Clearly the polyol method has the advantage of synthesizing LaNiO 3 particles in a smaller size with uniform distribution, compared with other synthesis routes . Figure c shows the SEM image of LaNiO 3 ‐NCNTs.…”

“…Accordingly, various perovskite ABO 3 materials (e.g., LaNiO 3 , LaCoO 3 , etc.) have been synthesized and tested for OER in the last few years . However, large bulk particles are the typical existence form of perovskite oxides that lack a large portion of active sites on surface.…”

Recent Progress on Nickel‐Based Oxide/(Oxy)Hydroxide Electrocatalysts for the Oxygen Evolution Reaction

“…It showed high catalytic activity and outstanding stability in 0.1 m KOH (an onset potential of 1.56 V and Tafel slope of 76 mV dec −1 ). Wong's group synthesized “high aspect ratio” motifs of pure LaNiO 3 perovskite nanorods towards OER for the first time by a template method . Coupled with high surface area, good conductivity and monodisperse morphology, LaNiO 3 provided a great deal of advantages for water oxidation catalysis.…”

“…Wong'sg roup synthesized "high aspect ratio" motifs of pure LaNiO 3 perovskite nanorods towards OER for the first time by a templatem ethod. [51] Coupled with highs urface area, good conductivity and monodisperse morphology, LaNiO 3 provided ag reat deal of advantages for water oxidation catalysis. Still, more comprehensive study involving in situ techniquesa nd theoretical calculations is anticipated for developing Ni-based perovskites electrocatalysts for OER.…”

Nanoscale Perovskites as Catalysts and Supports for Direct Methanol Fuel Cells

“…Indeed, ferroelectric ABO 3 perovskite-type oxides, with ag eneral formula of ABO 3 , are noteworthy fort heir advantageous dielectric, piezoelectric, electrostrictive, pyroelectric, and electro-optic properties with corresponding applicationsi nt he electronics industry for transducers, actuators, and high-k dielectrics. [1] In addition, it has been reported that perovskites can be appliedt owards a number of energy-related device configurations, including but not limited to fuel cells, solar cells, and metal-air batteries. [2] In at ypical perovskite structure, the B-site cation is positioned in octahedral coordination with adjacent oxygen atoms, and the A-site cation maintains ac orresponding dodecahedral coordination.…”