Enhanced photocatalytic oxygen evolution activity by formation of Ir@IrOx(OH)y core-shell heterostructure.

Developing efficient catalysts to accelerate the rate of oxygen evolution reaction (OER) is critical for photocatalytic water-splitting. In this work, metallic Ir, IrOx(OH)y, and core-shell Ir@IrOx(OH)y were synthesized and employed as OER catalysts for photocatalytic water oxidation. It was found that the Ir@IrOx(OH)y core-shell heterostructure catalyst showed the best photocatalytic performance among these three catalysts, with the oxygen evolution rate as high as 59.63 mmol g-1 h-1. Detailed investigations revealed that the excellent photocatalytic activity of Ir@IrOx(OH)y could be attributed to both the outstanding intrinsic activity of IrOx(OH)y shell and the efficient electron transfer between the photosensitizer and catalyst.