Surface Modification of Y2Ti2O5S2 with Co3O4 Co‐catalyst for Photocatalytic Oxygen Evolution

Abstract Y 2 Ti 2 O 5 S 2 (YTOS), an oxysulfide material, has attracted attention as a photocatalyst due to its optical absorption at wavelengths up to 650 nm, and its ability to split water into hydrogen and oxygen. However, the performance of YTOS in photocatalytic water splitting has remained low. One important factor accounting for this poor activity is the absence of highly efficient active sites. Surface modification with oxygen‐evolution co‐catalysts is indispensable for enhancing the activity and durability of non‐oxide narrow‐bandgap photocatalysts. Herein, we report the preparation of cobalt oxide (Co 3 O 4 )‐loaded YTOS for photocatalytic oxygen evolution. The Co 3 O 4 co‐catalyst was loaded by thermal decomposition of cobalt nitrate. The as‐obtained sample showed significantly enhanced activity in the oxygen evolution reaction compared with unmodified or IrO 2 ‐loaded YTOS. Transient absorption spectroscopy revealed that the Co 3 O 4 co‐catalyst captured holes and promoted charge separation, which accounted for the enhanced activity.