Synergistic coupling of Ni3ZnC0.7 decorated with homogeneous multimetal CoNiCuFe nitrogen-codoped carbon matrix as high-entropy catalysts for efficient overall water splitting

Due to unique electrical properties and high catalytic efficiency, transition metal nitrogen-codoped carbide (TM–N–C) has attracted tremendous interest as a multifunctional electrocatalyst for water splitting. Unlike traditional single-source modification, herein a novel pomegranate-like high-entropy (HE) electrocatalyst of Ni3ZnC0.7 decorated with homogeneous multimetal (Fe, Co, Cu, and Ni) nitrogen-codoped carbon matrix (Ni3ZnC0.7@CoNiCuFe–NC) is reported. It can be implemented by the simple thermal annealing method of multimetal codoped zeolitic imidazolate framework (ZIF). Benefiting from the synergistic effects of plentiful TM–N–C species, template effect of ZIF and distinct nanoporous structure, HE electrocatalyst Ni3ZnC0.7@CoNiCuFe–NC exhibits outstanding electrocatalytic performance. When applied in strong alkaline electrolyte (1.0 M KOH), the overpotentials of Ni3ZnC0.7@CoNiCuFe–NC present as low as 202 and 97 mV for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) at 10 mA cm−2 current density. Surprisingly as a bifunctional electrode, it can achieve the low cell voltage of 1.53 V at 10 mA cm−2 current density for overall water splitting, which is comparable to conventional IrO2||Pt/C electrode and superior to the recently reported analogous bifunctional catalysts. Thus, the work proposes the direction for the rational design of homogeneous distribution of TM–N–C material for water splitting in the green hydrogen energy industry.