Interfacial engineering of nanofibrous Ru/Cr2O3 heterojunction for efficient alkaline/acid-universal hydrogen evolution at ampere level

Abstract

Interfacial engineering of a heterostructured electrocatalyst is an efficient way to boost hydrogen production, yet still remains a challenging task to achieve superior performance at ampere-grade current density. Herein, nanofibrous Ru/Cr2O3 heterojunction is prepared for alkaline/acid-universal hydrogen evolution. Theoretical calculations reveal that the introduction of Cr2O3 modulates the electronic structure of Ru, which is beneficial for *H desorption, resulting in a superior HER performance at ampere-grade current density. Accordingly, the resultant Ru/Cr2O3 catalyst presents an ultra-low overpotential of only 88 mV and long-term stability of 300 h at 1 A cm-2 in 1 M KOH. Furthermore, it also exbibits a small overpotential of 112 mV and steadily operates for 300 h at 1 A cm-2 in 0.5 M H2SO4. These performances outperform not only the benchmark Pt/C catalyst but also most of the top-performing catalysts reported to date. This study offers a novel conceptual approach for designing highly efficient electrocatalysts that hold significant promise for industrial-scale water splitting applications.