Zn and Co Loaded Porous C Decorated Electrospun Nanofibers as Efficient Oxygen Evolution Reaction for Water Splitting

Abstract

Developing a clean and efficient noble metal free electrocatalyst for oxygen evolution reaction (OER) is urgently needed to accelerate water splitting green energy conversion systems. Herein, we reported the fabrication of a noble metal-free electrocatalyst based on Zn and Co loaded porous C decorated cellulose acetate-polyaniline (ZnCo-C/CA-PANI) electrospun nanofibers at the surface of nickel foam (NF). The smooth coating of CA-PANI electrospun nanofibers at the surface of NF helps in exposing the maximum fraction of ZnCo-C based electrocatalyst and uniform flow of ions at the entire surface, thus resulting in high OH − adsorption capability. The designed ZnCo-C/CA-PANI@NF electrode acts as an efficient electrocatalyst for oxygen evolution reaction (OER) in an alkaline medium and offers a lower onset potential (1.34 V vs RHE), a small Tafel slope of 42 mV/dec, and high stability. These results suggest a concept of exploring more such noble metal free hybrid materials that could induce the efficient electrocatalytic water splitting for sustainable energy conversion.

N-Coordinated cobalt single atom-integrated electrospun nanofibers for an efficient oxygen evolution reaction

“…The principal diffraction peaks of BM-ZIF are (011), (022), (112), (022), (013), and (222), which correlate with the diffraction angles of 7.34, 10.39, 12.74, 14.76, 17.1, and 18.1°, respectively, matching well with already reported literature. 30 However, the primary peaks in face-centered cubic, Co have diffraction angles of 46.6, 51.2, and 74.7° related to diffraction planes (111), (200), and (220), respectively, and are consistent with previously published literature. 27 The presence of C is indicated by a sizable diffraction peak with the plane (022) matching a diffraction angle of 26.76°.…”

“…S4B, D and F, ESI†). 30 Here, E c is the reduction and E 1/2 is the formal potential of metal redox, R , T , F , and k s stand for general gas constant, absolute temperature, Faraday constant, and redox constant, respectively. Whereas n and α represent the number of electron transfers and the electron transfer coefficient.…”

“…Based on these observations, a mechanism for the OER was proposed that demonstrates the involvement of four electron–proton transfers as well as the production of an oxo-intermediate (eqn (2)–(5)) at the surface of the designed electrode and is consistent with the reported literature. 35 M + OH − ↔ M–OH + e − M–OH + OH − ↔ M–O + H 2 O + e − M–O + OH − ↔ M–OOH + e − M–OOH + OH − ↔ M + O 2 + H 2 O +e − …”

“…Furthermore, to study reaction kinetics, the HO À ion adsorption capability of the developed electrodes was evaluated by calculating k s values by applying the Laviron equation 2,35 (eqn (1)). In this regard, CV measurements of CP/NF, NC-Co-SAC/NF and NC-Co-SAC@CP/NF electrodes were performed at increasing scan rates (5-25 mV s À1 ) in 1 M KOH (Fig.…”

“…Our proposed mechanism is also in accordance with the reported literature. 35 It is interesting to note that the dense extended dendritic fibrous network of CP electrospun nanofibers provides a homogenous flow of ions at the entire surface with a maximum exposition of Co-SA nanocatalysts, for the fast and smooth formation of O 2 molecules. These results suggest high OH À adsorption capability (due to the higher binding strength of the Co-SAC to the OH À intermediate) of the designed electrode.…”