Molecule-based water-oxidation catalysts (WOCs) : cluster-size-dependent dye-sensitized polyoxometalates for visible-light-driven O2 evolution

• Main Authors: Gao, Junkuo, Cao, Shao-Wen, Tay, Qiuling, Liu, Yi, Yu, Lingmin, Ye, Kaiqi, Mun, Peter Choon Sze, Li, Yongxin, Rakesh, Ganguly, Loo, Say Chye Joachim, Chen, Zhong, Zhao, Yang, Xue, Can, Zhang, Qichun
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2013
• Subjects: DRNTU::Science
• Online Access: https://hdl.handle.net/10356/97424; http://hdl.handle.net/10220/12061
• Institution: Nanyang Technological University

From atomic level to understand the cluster-size-dependant behavior of dye-sensitized photocatalysts is very important and helpful to design new photocatalytic materials. Although the relationship between the photocatalytic behaviors and particles' size/shape has been widely investigated by theoretical scientists, the experimental evidences are much less. In this manuscript, we successfully synthesized three new ruthenium dye-sensitized polyoxometalates (POM-n, n relate to different size clusters) with different-sized POM clusters. Under visible-light illumination, all three complexes show the stable O 2 evolution with the efficient order POM-3 > POM-2 > POM-1. This cluster-size-dependent catalytic behavior could be explained by the different numbers of M = Ot (terminal oxygen) bonds in each individual cluster because it is well-known that Mo = Ot groups are the catalytically active sites for photooxidation reaction. The proposed mechanism of water oxidation for the dye-sensitized POMs is radical reaction process. This research could open up new perspectives for developing new POM-based WOCs.