Abstract: Hydrogen production via seawater electrolysis, leveraging sustainable energy sources such as offshore wind or solar energy, has immense application potential. However, the abundance of chloride ions (Cl^-) in seawater leads to the generation of chlorine gas and hypochlorite at the anode during electrolysis, posing a severe threat of corrosion of the catalyst and electrolytic equipment. Herein, we synthesize a NiMo-based catalyst adorned with surface-anchored graphene quantum dots (GQDs). This catalyst possesses excellent Cl^- exclusion capabilities. The Mo-NiS/Se@GQDs core-shell nanorod catalyst requires only 170 mV of overpotential to attain a current density of 10 mA cm^-2 and operates stably for 200 h without degradation across a broad current density range from 100 to 400 mA cm^-2. This remarkable electrocatalytic stability arises from the dynamic and efficient repulsion of Cl^- at the catalytic interface, as proven by the post-reaction analysis of Cl^- distribution within the catalyst. Furthermore, a potentiodynamic polarization test revealed that the Mo-NiS/Se@GQDs catalyst has high corrosion potential (0.66 V) and low corrosion current density (122.93 μA cm^-2), underscoring its excellent corrosion resistance. This research presents a novel approach to mitigate Cl^- corrosion during hydrogen production through seawater electrolysis, laying a solid foundation for advancing sustainable energy conversion technologies.

Key words: Electrolytic seawater, OER, Stability, GQDs, Inhibit chlorine chemistry