Abstract

Herein, we report the synthesis of a uniform, sphere-like NiCoFeRuIr high-entropy alloy (NiCoFeRuIr HEA) via the pulsed laser irradiation in liquid method. The resulting NiCoFeRuIr HEA exhibits outstanding nitrite reduction reaction (NO₂⁻RR) performance, achieving a high NH₃ yield rate of 2.34 mg⸱h⁻¹⸱cm⁻² and Faradaic efficiency of 95.78% at −0.6 V vs. the reversible hydrogen electrode. Mechanistic insights obtained from in situ Raman spectroscopy, ex situ X-ray diffraction, and density functional theory calculations further support the origin of the outstanding NO₂⁻RR performance of the NiCoFeRuIr HEA electrocatalyst. Furthermore, NiCoFeRuIr HEA serves as an efficient cathode in a Zn–nitrite battery, enabling simultaneous NO₂⁻ remediation, NH₃ production, and electricity generation with a power density of 3.80 mW⸱cm⁻². Thus, this study highlights the potential of the pulsed laser–driven synthesis of HEA electrocatalysts, paving the way for integrated pollutant remediation, green chemical production, and sustainable energy applications.