Supporting IrOx nanosheets on hollow TiO2 for highly efficient acidic water splitting
Ge Yu, Ruilong Li, Yanmin Hu, Xingen Lin, Ze Lin, Dongyang Wu, Gongming Wang, Xun Hong
Abstract
The efficiency of proton exchange membrane water electrolysis (PEM-WE) for hydrogen production is heavily dependent on the noble metal iridium-based catalysts. However, the scarcity of iridium limits the large-scale application of PEM-WE. To address this issue, it is promising to select an appropriate support because it not only enhances the utilization efficiency of noble metals but also improves mass transport under high current. Herein, we supported amorphous IrO x nanosheets onto the hollow TiO 2 sphere (denoted as IrO x ), which demonstrated excellent performance in acidic electrolytic water splitting. Specifically, the annealed IrO x catalyst at 150 °C in air exhibited a mass activity of 1347.5 A·g Ir −1 , which is much higher than that of commercial IrO 2 of 12.33 A·g Ir −1 at the overpotential of 300 mV for oxygen evolution reaction (OER). Meanwhile, the annealed IrO x exhibited good stability for 600 h operating at 10 mA·cm −2 . Moreover, when using IrO x and annealed IrO x catalysts for water splitting, a cell voltage as low as 1.485 V can be achieved at 10 mA·cm −2 . The cell can continuously operate for 200 h with negligible degradation of performance.