Fe-Doped Ni-Phytate/Carbon Nanotube Hybrids Integrating Activated Lattice Oxygen Participation and Enhanced Photothermal Effect for Highly Efficient Oxygen Evolution Reaction Electrocatalyst.

Developing highly efficient oxygen evolution reaction (OER) electrocatalysts is critical for hydrogen production through electrocatalytic water splitting, yet it remains a significant challenge. In this study, a novel OER electrocatalyst, Fe-doped Ni-phytate supported on carbon nanotubes (NiFe-phy/CNT), which simultaneously follows lattice oxygen mechanism (LOM) and exhibits a photothermal effect, is synthesized through a facile and scalable co-precipitation method. Experimental results combined with theoretical calculations indicate that introducing Fe can facilitate the structural reconstruction of NiFe-phy/CNT to form highly active NiFe oxyhydroxides, switch OER pathway to LOM from the adsorbate evolution mechanism, and reinforce the photothermal effect to counterbalance the enthalpy change during OER process while reducing its activation energy. Therefore, under near-infrared light irradiation, NiFe-phy/CNT demonstrates exceptional OER activity, featuring low overpotentials of 237, 275, and 286 mV at 100, 500, and 1000 mA cm, respectively. Moreover, this electrocatalyst demonstrates the capability of large-scale synthesis and can be stored for over 120 days with a negligible decrease in activity. This work presents a novel conceptual approach to integrate lattice oxygen redox chemistry with photothermal effect for designing highly efficient OER electrocatalysts.