Ion‐change promoting Co nanoparticles@N‐doped carbon framework on Co₂SiO₄/rGO support forming “double‐triple‐biscuit” structure boosts oxygen evolution reaction

Abstract

Exploring economic and high-performance electrocatalysts to decrease the overpotential of oxygen evolution reaction (OER) and facilitate its reaction kinetics is a frontier subject in line with green energy. Herein, metal-organic framework (MOF)-derived Co nanoparticles@N-doped carbon (Co NPs@N,C) is rationally designed on sandwich-like cobalt silicate/reduced graphene oxide (Co 2 SiO 4 /rGO) support to acquire Co NPs@N,C/Co 2 SiO 4 /rGO "double-triplebiscuit"-like structure as enhanced OER electrocatalysts. Co NPs@N,C on Co 2 SiO 4 /rGO support optimizes its geometric architecture and introduces new active sites. The "double-triple-biscuit"-like Co NPs@N,C/Co 2 SiO 4 /rGO structure achieves excellent OER ability compared with the existing materials based on transition metal silicates (TMSs). The overpotential of 278 mV is achieved at the current density of 10 mA cm −2 , and it is prominently higher than Co 2 SiO 4 /rGO support (390 mV). This excellent OER activity is rooted in its structural peculiarity, enabling efficient ion and electron transport. Co NPs@N,C are highly dispersed on the Co 2 SiO 4 /rGO support, increasing the active sites and avoiding self-aggregation of Co NPs in the OER process. This work combines the advantages of Co 2 SiO 4 /rGO support with the triple biscuits' structure and MOF to implement the preparation of boosted Co NPs@N,C/Co 2 SiO 4 /rGO, and it opens a new avenue for designing novel architectures to promote the OER activity of TMSs.

Stability challenges and opportunities of NiFe‐based electrocatalysts for oxygen evolution reaction in alkaline media

“…Seawater resources are abundant and seawater has high ionic conductivity, which makes seawater electrolysis a key strategy for addressing the global energy crisis. [9][10][11][12] When the overpotential of OER is less than 480 mV in alkaline media, chlorine evolution reactions are not expected to occur. [13] Therefore, investigating OER performance in alkaline media holds greater potential for development than that in acidic media for large-scale industrial applications.…”

“…[14,15] The OER in alkaline media (4OH − ↔ 2H 2 O(l) + O 2 (g) + 4e − ) is triggered by multiple electron transfer steps with oxygen-oxygen bond formation and is thermodynamically more challenging than the two electron transfer process (2H 2 O + 2e − ↔ 2OH − + H 2 ) in the HER. [12] Consequently, the OER process is more demanding in energy conversion technology due to the requirement for a high potential to overcome the difficult 4e − redox process, which determines overall efficiency. [16][17][18][19][20][21] Designing and exploring OER electrocatalysts with long-term stability is significant to reaching the objective of large-scale hydrogen production for industrial landscapes.…”

Unveiling the electron configuration‐dependent oxygen evolution activity of 2D porous Sr‐substituted LaFeO3 perovskite through microwave shock

“…The oxygen evolution reaction (OER) is a crucial module in various renewable energy storage and conversion devices, including water electrolysis, carbon dioxide reduction, and rechargeable metal-air batteries. [1][2][3][4][5][6][7][8] However, the intricate four-proton coupled electron transfer process of OER poses significant challenges to achieving high energy conversion efficiency. [9][10][11][12] Despite the recognition of traditional noble metal-based electrocatalysts, such as RuO 2 and IrO 2 , as benchmark materials for OER, their widespread deployment on a larger scale is restricted due to the high cost and inherent instability.…”

Mn‐doping ensuring cobalt silicate hollow spheres with boosted electrochemical property for hybrid supercapacitors

“…Carbon neutralization initiative (CNI) has been one of the biggest hotspots to alleviate energy and environmental issues 1 . Developing energy storage and conversion systems with sustainable and clean features is a hot topic in the age of CNI 2–5 . Supercapacitors (SCs) occupy a unique position in the realm of energy storage devices, positioned between batteries and conventional capacitors.…”

“…1 Developing energy storage and conversion systems with sustainable and clean features is a hot topic in the age of CNI. [2][3][4][5] Supercapacitors (SCs) occupy a unique position in the realm of energy storage devices, positioned between batteries and conventional capacitors. They have the advantages of outstanding long cycle life, high instantaneous power, broad operating temperature range, maintenance-free operation, and environmental friendliness, which have attracted great interest in the past decades all over the world.…”