Tailoring atomically local electric field of NiFe layered double hydroxides with Ag dopants to boost oxygen evolution kinetics.

The demand for clean energy sources has driven focus towards advanced electrochemical systems. However, the sluggish kinetics of the oxygen evolution reaction (OER) constrain the energy conversion efficiency of relevant devices. Herein, a one-step method is reported to grow oxygen vacancies (V _o ) rich NiFeAg layered double hydroxides nanoclusters on carbon cloth (V _o -NiFeAg-LDH/CC) for serving as the self-supporting electrode to catalyze OER. The OER performance of V _o -NiFeAg-LDH/CC has been remarkably enhanced through Ag and V _o co-modification compared with pristine NiFe-LDH, achieving a low Tafel slope of 49.7 mV dec ^-1 in 1 m KOH solution. Additionally, the current density of V _o -NiFeAg-LDH/CC is 3.23 times higher than that of the state-of-art IrO ₂ at 2 V under an alkaline flow electrolyzer setup. Theoretical calculations and experimental results collectively demonstrate that Ag dopant and V _o strengthen the O* adsorption with active sites, further promoting the deprotonation step from OH* to O* and accelerating the catalytic reaction. In a word, this work clarifies the structural correlation and synergistic mechanism of Ag dopant and V _o , providing valuable insights for the rational design of catalyst for renewable energy applications.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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