Fabrication of hierarchically structured S-doped NiFe hydroxide/oxide electrodes for solar-assisted oxygen evolution reaction in seawater splitting

Electrocatalytic seawater splitting is an eco-friendly approach for high-purity hydrogen production, but still hampered by anodic oxygen evolution reaction (OER). Besides the exploitation of efficient electrocatalysts, integrating solar energy into electrocatalytic system can offer a complementary degree of freedom to modulate such electrochemical process. Herein, we construct the hierarchically structured S-doped NiFe hydroxide/oxide on carbon cloth (S-NiFeOxHy/CC) that exhibits both intrinsically good OER activity and solar light absorption capability for solar-assisted OER in seawater splitting. When exposed to solar light, the S-NiFeOxHy/CC delivers a current density of 10 mA cm−2 at overpotential of 250 mV with a low Tafel slope of 63 mV dec−1 and good stability in alkaline simulated seawater. This work affords a promising strategy to intensify the electrocatalytic reaction by solar energy for seawater electrolysis, which has important implications for efficient hydrogen production.