Titanium-doped Ni3S2 nanosheets with enhanced activity and durability for oxygen evolution reaction via electronic structure modulation

초록

Developing earth-abundant electrocatalysts with exceptional activity and durability for the oxygen evolution reaction remains critical for advancing alkaline water electrolysis. Herein, we report strategic titanium doping of Ni3S2 nanosheets to enhance both catalytic performance and stability through electronic structure modulation. Electron-deficient Ti4+ cations systematically withdraw electron density from neighboring Ni centers, progressively increasing the Ni3+ population up to 31.9% while strengthening metal-sulfur bonding. The optimized Ti0.05Ni2.95S2 catalyst exhibits exceptional performance with a low overpotential of 261 mV at 50 mA cm−2, minimal Tafel slope of 75.47 mV dec−1, and outstanding stability showing only 4 mV increase after 2000 cycles—substantially outperforming pristine Ni3S2 and commercial RuO2. Post-catalysis characterization reveals dual synergistic benefits. Ti doping facilitates expedited transformation to catalytically active β-NiOOH at lower overpotentials while effectively suppressing sulfur leaching through strengthened bonding, maintaining the conductive Ni3S2 backbone. These findings demonstrate that rational heteroatom doping represents a versatile strategy for simultaneously optimizing activity and durability in transition metal chalcogenide electrocatalysts for practical water splitting. Copyright © 2026. Published by Elsevier B.V.

키워드