Pulsed laser-tuned ruthenium@carbon interface for self-powered hydrogen production via zinc–hydrazine battery coupled hybrid electrolysis
Huieun Ahn, Raja Arumugam Senthil, Sieon Jung, Anuj Kumar, Mohd Ubaidullah, Myong Yong Choi
Abstract
Herein, we report the synthesis of selectively face-centered cubic structured ruthenium nanospheres covered in graphitic carbon (denoted as Ru@C) using an effective and innovative pulsed laser ablation in liquid strategy. The Ru@C‒200 catalyst exhibited a low overpotential of 48 mV for hydrogen evolution reaction (HER) and an ultralow oxidation potential of −8 mV (vs. reversible hydrogen electrode) for hydrazine oxidation reaction (HzOR) at 10 mA cm −2 , maintaining long-term durability for over 100 h, demonstrating its dual-functional activity. This performance was attributed to the robust synergistic coupling between the Ru core and C shell, as confirmed by in situ electrochemical studies and density functional theory investigations. As a result, overall hydrazine splitting (OHzS) in the Ru@C‒200||Ru@C‒200 system requires only low cell voltages of 0.11 and 0.70 V at 10 and 100 mA cm −2 , respectively. Moreover, a rechargeable zinc–hydrazine (Zn–Hz) battery, fabricated using the Ru@C‒200 catalyst as the cathode and Zn foil as the anode, exhibited a high energy efficiency of 90% and efficient H 2 production, validating its remarkable ability for practical applications. Notably, coupling Zn–Hz battery with OHzS system encourages self-powered H 2 production. This study provides potential guidance for engineering robust electrocatalysts for large-scale H 2 production while purifying hydrazine-containing industrial sewage. • A pulsed laser technology was used to synthesize Ru@C core‒shell electrocatalysts. • Ru@C synthesized at 200 mJ laser power exhibited superior HER and HzOR activity. • The Ru@C‒200||Ru@C‒200 pair needed only 0.11 V at 10 mA cm −2 in the OHzS process. • A rechargeable Zn–Hz battery achieved a 90 % energy efficiency with H 2 production. • Integration of Zn–Hz battery with OHzS system enabled a self-powered H 2 production.