Electronegativity-Induced Valence State Augmentation of Ni and Co through Electronic Redistribution between Co-Ni₃N/CeF₃ Interfaces for Oxygen Evolution Reaction

Abstract

The development of high-performance and inexpensive electrocatalysts for the oxygen evolution reaction is one of the most desired objectives in energy conversion reactions. Due to sluggish reaction kinetics, the commercialization of such processes could not be achieved yet. Choosing an appropriate coupling interface to boost the catalyst performance is essential for the creation of high-efficiency electrocatalysts. Herein, metal-nitride and metal-fluoride heterostructures are reported with an extremely low overpotential of 180 mV at a current density of 10 mA cm −2 for OER application. The Co−Ni 3 N/CeF 3 catalyst shows strong interfacial interaction, causing significant electronic redistribution between Co−Ni 3 N and CeF 3 phases. X-ray photoelectron spectroscopy studies reveal the charge transfer from the Co−Ni 3 N to the CeF 3 phase, resulting in the augmentation in the valence states of Co and Ni and making them highly active sites for the adsorption of intermediates (O*, OH*, and HOO*). This phenomenon is possibly driven by the high polarity of CeF 3 due to the presence of highly electronegative F atoms. The stability study of the catalyst was performed for 120 h at large current densities of 100 and 200 mA cm −2 . The detailed analysis of the surface reconstruction of Co−Ni 3 N/CeF 3 is also carried out after a long-term stability test. This work offers a fresh look at the possibilities of the design and fabrication of an efficient and low-cost catalyst.

Unfolding the Electrocatalytic Efficiency of Ultrastable CoFeLDH Nanorods by Creating Oxygen Vacancies for OER

“…Superhydrophilic catalysts facilitate the rapid transfer of ions from the electrolyte to the electrode surface, thereby accelerating the mass transport process and ultimately enhancing electrocatalytic performance. 56 To delve deeper into the structural and mechanistic aspects of the OER activity within both the pristine CoFeLDH and the structure with oxygen vacancies (O v ), we conducted DFT (density functional theory) calculations. The structures constructed for DFT calculations are presented in the SI, Figure S10, and the differences between pristine and vacancy structures are shown in Figure 6a.…”

“…The contact angle was measured at 0°, confirming the superhydrophilic nature of the catalyst surface. Superhydrophilic catalysts facilitate the rapid transfer of ions from the electrolyte to the electrode surface, thereby accelerating the mass transport process and ultimately enhancing electrocatalytic performance …”

Electronic Redistribution Through the Interface: A Prodigy that Enhances Electrocatalysis

“…[42] The presence of a localized charge distribution at the interface results in the generation of an electro/nucleophilic area, which enhances the adsorption of intermediates. [43] Conversely, the presence of an electron-rich site significantly boosts the ability of hydrogen adsorption and also enhance other electroreduction process, whereas the presence of electron-deficient site significantly boosts the OER. [44][45][46][47] Despite the involvement of several electron transfers and the generation of complicated intermediates, the rational design of electrocatalysts using heterojunction engineering simplifies the process and significantly enhances its kinetic efficiency.…”

“…Heterojunctions provide a localized charge distribution at the interface as a result of an inherent electric field created by the disparities in work function of the materials involved [42] . The presence of a localized charge distribution at the interface results in the generation of an electro/nucleophilic area, which enhances the adsorption of intermediates [43] . Conversely, the presence of an electron‐rich site significantly boosts the ability of hydrogen adsorption and also enhance other electroreduction process, whereas the presence of electron‐deficient site significantly boosts the OER [44–47] .…”

Strong coupling effect induced surface reconstruction of CeF3–Ni3N to form CeF3–NiOOH for the oxygen evolution reaction

“…The primary reason for their poor activity is the excessive e g -orbital lling of nickel, which limits OER performance. [37][38][39] This excess e g -orbital lling also affects the activity of the formed oxyhydroxide. This issue can be addressed by adding a second component to Ni 3 N's original single component to create a cooperative interface.…”