Electronically Coupled Ru/RuO 2 Interfaces Induced by Laser Thermal Shock for Energy‐Efficient Hydrazine‐Assisted Hydrogen Production
Sieon Jung, Raja Arumugam Senthil, Anuj Kumar, Myong Yong ChoiABSTRACT
In this work, we report a rapid, one‐step continuous‐wave CO 2 laser–induced thermal shock process for synthesizing Ru/RuO 2 with coherent metallic–oxide interfaces. The ultrafast laser process enables the precise creation of an electronically coupled Ru/RuO 2 interface with superior bifunctional activity toward both the hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HzOR). Notably, the optimized Ru/RuO 2 ‐1 catalyst (1:1 molar ratio of Ru precursor to KOH) exhibits ultralow overpotential of 34 mV for HER and oxidation potential of −56 mV versus the reversible hydrogen electrode for HzOR at a current density of 10 mA·cm −2 in alkaline media. In overall hydrazine splitting, a symmetric Ru/RuO 2 ‐1||Ru/RuO 2 ‐1 pair achieves current densities of 10 and 150 mA·cm −2 at ultralow cell voltages of 0.044 and 0.717 V, respectively. Furthermore, a Zn–hydrazine battery assembled with Ru/RuO 2 ‐1 as the cathode enables self‐powered hydrogen generation with stable operation for 200 h. Advanced in situ and ex situ spectroscopies combined with density functional theory reveal that strong electronic coupling at the Ru/RuO 2 interface promotes intermediate adsorption and lowers kinetic barriers for both the HER and HzOR. This study introduces a CO 2 laser‐induced interfacial engineering strategy for designing advanced electrocatalysts for self‐powered and energy‐efficient H 2 production technologies.