Flux‐Assisted Synthesis of Y<sub>2</sub>Ti<sub>2</sub>O<sub>5</sub>S<sub>2</sub> for Photocatalytic Hydrogen and Oxygen Evolution Reactions
Lihua Lin, Pongpen Kaewdee, Vikas Nandal, Ryota Shoji, Hiroyuki Matsuzaki, Kazuhiko Seki, Mamiko Nakabayashi, Naoya Shibata, Xiaoping Tao, Xizhuang Liang, Yiwen Ma, Takashi Hisatomi, Tsuyoshi Takata, Kazunari Domen
Abstract
Abstract Photocatalytic water splitting is an ideal means of producing hydrogen in a sustainable manner, and developing highly efficient photocatalysts is a vital aspect of realizing this process. The photocatalyst Y 2 Ti 2 O 5 S 2 (YTOS) is capable of absorbing at wavelengths up to 650 nm and exhibits outstanding thermal and chemical durability compared with other oxysulfides. However, the photocatalytic performance of YTOS synthesized using the conventional solid‐state reaction (SSR) process is limited owing to the large particle sizes and structural defects associated with this synthetic method. Herein, we report the synthesis of YTOS particles by a flux‐assisted technique. The enhanced mass transfer efficiency in the flux significantly reduced the preparation time compared with the SSR method. In addition, the resulting YTOS showed improved photocatalytic H 2 and O 2 evolution activity when loaded with Rh and Co 3 O 4 co‐catalysts, respectively. These improvements are attributed to the reduced particle size and enhanced crystallinity of the material as well as the slower decay of photogenerated carriers on a nanosecond to sub‐microsecond time range. Further optimization of this flux‐assisted method together with suitable surface modification is expected to produce high‐quality YTOS crystals with superior photocatalytic activity.