Cr2O3 Nanoparticles on Ba5Ta4O15 as a Noble-Metal-Free Oxygen Evolution Co-Catalyst for Photocatalytic Overall Water Splitting

The (111)-layered perovskite material Ba5Ta4O15 represents a suitable photoabsorber with remarkable photocatalytic activity in overall water splitting. We are the first to demonstrate overall water splitting without the presence of a noble-metalbased co-catalyst over this catalyst. The photocatalytic activity of Ba5Ta4O15 was investigated by overall water splitting after reductive photodeposition of amorphous Cr2O3. The formation of Cr2O3 nanoparticles for water splitting was evidenced by X-ray photoelectron spectroscopy and transmission electron microscopy. The reductive photodeposition of very low amounts of Cr2O3 on Ba5Ta4O15 induces stable rates in overall water splitting up to 465 mu molh(-1) H-2 and 228 mu molh(-1) O-2.