Electronic structure modulation of Ce-doped Co3O4 nanowires by interfacial RuO2 species for durable acidic water oxidation

Ce-doped Co 3 O 4 nanowire arrays with interfacial RuO 2 were constructed on Ti mesh. • The optimized 5-Ru-CoCe/Ti shows 198 ± 15 mV at 10 mA cm −2 for acidic OER. • The self-supported electrode delivers stable operation for over 200 h in 0.5 M H 2 SO 4 . • Ce doping and RuO 2 coupling tune the electronic structure and accelerate OER kinetics. Co-based catalysts have emerged as highly promising electrocatalysts for the acidic oxygen evolution reaction (OER). However, their elevated surface energies lead to instability and inefficacy, particularly at high current densities, impeding their utility in large-scale application. Herein, we report a self-supported electrode composed of interfacial RuO 2 -decorated Ce-doped Co 3 O 4 nanowire arrays on Ti mesh, fabricated through hydrothermal growth, annealing, and cyclic impregnation-calcination. The optimized 5-Ru-CoCe/Ti catalyst delivers an overpotential of only 198 ± 15 mV at 10 mA cm −2 , a Tafel slope of 103.2 mV dec −1 , and stable operation for over 200 h in 0.5 M H 2 SO 4 . Experimental characterizations and density functional theory calculations reveal that Ce doping and RuO 2 /Co 3 O 4 interfacial coupling modulate the local electronic structure and promote interfacial electron redistribution. This electronic modulation enhances –OH adsorption and accelerates OER kinetics, thus lowering the energy barrier for the *O to *OOH conversion. These findings demonstrate that interfacial electronic structure engineering is an effective strategy for designing low-noble-metal electrocatalysts with high activity and durability for acidic water oxidation. Download: Download high-res image (123KB) Download: Download full-size image