CoTiO3/NrGO nanocomposites for oxygen evolution and oxygen reduction reactions: Synthesis and electrocatalytic performance

Abstract

Oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts play an important role in energy conversion and storage devices, but highly active and robust nonprecious metal catalysts are required to address the cost and durability issues. In this work, a modified gel methodology has been used to obtain nanocomposites of perovskite CoTiO 3 and N-doped reduced graphene oxide (NrGO). Moreover, the influence of the annealing extent in the synthesis has been studied. The composites show higher activity in oxygen evolution and reduction reactions in alkaline environment compared to sole ilmenite, which is related to a strong interaction between cobalt titanate and NrGO carbon matrix. The annealing duration appears as a key variable to modulate the physicochemical properties and the electrochemical behavior. The composite prepared at the largest duration (3 hours) exhibit enhanced bifunctional properties for ORR and OER, with onset potentials of 0.93 V and 1.53 V vs. RHE respectively, which is mainly attributed to higher concentration of nitrogen, larger extent of defects and/or the presence of more oxidized Co species in the nanocomposite.

Non-precious Melamine/Chitosan Composites for the Oxygen Reduction Reaction: Effect of the Transition Metal

“…The surface oxidation of the iron samples does not allow the analysis of the inner layer, and therefore the detection of the iron carbide observed by XRD. Co2p shows binding energies of Co2p3/2 and Co2p1/2 at 782.3 and 798.1 eV, respectively, and the respective "satellite" peaks, which can be attributed to Co 2+− like species (Wagner et al, 1979;Luque-Centeno et al, 2020). The Cu2p core level spectra is displayed in Figure 4C.…”

Graphene-based materials as electrocatalysts for the oxygen evolution reaction: a review

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Electronic modulation and interface engineering of electrospun nanomaterials‐based electrocatalysts toward water splitting

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