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

Based on DFT calculations, the BEFs was successful construction at the interface between the Ru clusters and CeO2. Under the action of a strong BEF, the electron-deficient Ru atoms can optimize the adsorption strength of H* and H2O, thereby promoting HER kinetics. [Display omitted] •Based on DFT calculations, a Ru/CeO2 Mott-Schottky heterojunction with Strong BEF effect is constructed by a facile method.•Under the action of a strong BEF the electron-deficient Ru atoms can optimize the adsorption energy of H* and H2O.•The Ru/CeO2 catalyst achieves a power density of up to 94.5 mW cm-2 in alkaline-acidic Zn-H2O cell applications.•This work combines hydrogen production with power generation and provides a towardly way for sustainable energy conversion. 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/CeO2) with a built-in electric field (BEF) based on density functional theory (DFT). The Ru/CeO2 achieves the criterion current density of 10 mA cm−2 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/CeO2 catalyst could be due to the successful construction of BEF at the interface between the prepared Ru clusters and CeO2. Under the action of BEF, the electron-deficient Ru atoms can optimize the adsorption energy of H* and H2O and thus promote HER kinetics. Furthermore, the Ru/CeO2 catalyst delivers a power density of approximately 94.5 mW cm−2 in alkaline-acidic Zn-H2O cell applications while maintaining good H2 production stability. In this work, we optimize the electrocatalytic performance of the Ru/CeO2 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.