Reduced Graphene Oxide- and Triethanolamine-Decorated Nickel Oxide Electrocatalyst for Efficient Water/Saline Water Oxidation

The development of low-cost, highly efficient catalysts for the oxygen evolution reaction (OER) is one of the key steps for advancing renewable energy production. Increasing the density of high-valence metal species, coupled with rapid surface reconstruction, is a promising, but challenging design strategy for efficient OER catalysts. Herein, we report a facile electronic modulation approach for Ni oxide catalyst design (Ni/CP-TEA-GO), achieved by codecorating the surface with reduced graphene oxide (GO) and an N-group-containing ligand, triethanolamine (TEA), via a simple two-step electrodeposition process. The electrochemically reduced GO serves as an anchor site to couple the Ni sites and induces strong electronic interactions with the Ni sites, improving stability and promoting the formation of high-valence Ni species as active sites. Concurrently, the leaching of TEA further accelerates the generation of high-valence Ni species under the anodic potential. This functional surface modification approach is both cost-effective and scalable, distinguishing it from more complex or noble-metal-based strategies. The Ni/CP-TEA-GO exhibits outstanding OER performance, with a low overpotential of 230 mV at 10 mA·cm^-2, rapid OER kinetics with a small Tafel slope of 31 mV·dec^-1, and great long-term stability. Moreover, it achieves an overpotential of 360 mV to drive a current density of 50 mV·cm^-2 for simulated alkaline seawater oxidation, exhibiting remarkable durability over a 100-h test. This work presents an effective and simple pathway for tailoring the electronic environment to facilitate the accessibility of highly oxidized metal species for the rational design of efficient and cost-effective OER electrocatalysts.