Ruthenium clusters decorated on lattice expanded hematite Fe2O3 for efficient electrocatalytic alkaline water splitting

Abstract

Electrocatalytic water splitting in alkaline media plays an important role in hydrogen production technology. Normally, the catalytic activity of commonly used transition metal oxides usually suffers from unsatisfactory electron conductivity and unfavorable binding strength for transition intermediates. To boost the intrinsic catalytic activity, we propose a rational strategy to construct lattice distorted transition metal oxides decorated with noble-metal nanoclusters. This strategy is verified by loading ruthenium clusters onto lithium ion intercalated hematite Fe₂O₃, which leads to significant distortion of the FeO₆ unit cells. A remarkable overpotential of 21 mV with a Tafel slope of 39.8 mV dec⁻¹ is achieved at 10 mA cm⁻² for the hydrogen evolution reaction in 1.0 M KOH aqueous electrolyte. The assembled alkaline electrolyzer can catalyse overall water splitting for as long as 165 h at a current density of 250 mA cm⁻² with negligible performance degradation, indicating great potential in the field of sustainable hydrogen production.