Constructing built-in electric field via ruthenium/cerium dioxide Mott-Schottky heterojunction for highly efficient electrocatalytic hydrogen production.

Ensuring the consumption rate of noble metals while guaranteeing satisfactory hydrogen evolution reaction (HER) performance at different pH values is imperative to the development of Ru-based catalysts. Herein, we design a Mott-Schottky electrocatalyst (Ru/CeO) with a built-in electric field (BEF) based on density functional theory (DFT). The Ru/CeO achieves the criterion current density of 10 mA cm at overpotentials of 55 mV, 80 mV, and 120 mV in alkaline, acidic and neutral media, respectively. Both theoretical calculations and experimental analysis confirm that the improved HER activity in the Ru/CeO catalyst could be due to the successful construction of BEF at the interface between the prepared Ru clusters and CeO. Under the action of BEF, the electron-deficient Ru atoms can optimize the adsorption energy of H* and HO and thus promote HER kinetics. Furthermore, the Ru/CeO catalyst delivers a power density of approximately 94.5 mW cm in alkaline-acidic Zn-HO cell applications while maintaining good H production stability. In this work, we optimize the electrocatalytic performance of the Ru/CeO catalyst through examination of the interfacial BEF electrical charge, which combines hydrogen production with power generation and provides a promising method for sustainable energy conversion.