posted on 2023-11-20, 13:20authored byDina Zhang, Hao Cheng, Xiaoyu Hao, Qian Sun, Tianyi Zhang, Xinwu Xu, Zelin Ma, Tong Yang, Jun Ding, Xuqing Liu, Ming Yang, Xiaolei Huang
Electrocatalytic seawater splitting offers a promising
avenue for
cost-effective and environmentally friendly hydrogen production. However,
the activity of catalysts has significantly degraded at high-salinity
conditions, preventing commercial-scale practical applications. Here,
we demonstrate that iron-doped nickel-based electrocatalysts with
low doping concentration exhibit an outstanding performance for the
oxygen evolution reaction (OER) in seawater, particularly at high-salinity
conditions. Notably, the OER catalysts present only a marginal increase
in overpotential of ∼5 mV as the sodium chloride concentration
in the electrolyte increases from 0 M to saturation. Furthermore,
the low iron-doped electrocatalysts sustain consistent oxygen generation
over 100 h of operation in a saturated seawater electrolyte. Supported
by first-principles calculations, we unravel that low-concentration
iron doping in Ni-based catalysts can mitigate chloride ion adsorption,
thereby amplifying the OER activity in saturated seawater electrolytes,
which is in contrast with high iron-doped electrocatalysts. Our work
provides a useful perspective on designing catalysts for electrolytic
seawater OER, potentially paving the way for large-scale implementation
of seawater splitting technologies.