In 2008, Geletii Y V et al. reported that Rb8K2[{Ru4O4(OH)2(H2O)4}(β-SiW10O36)2]•25H2O as a homogeneous photocatalyst could efficiently and rapidly catalyze water oxidation reaction. In addition, this POM-based photocatalyst can maintain a stable structure in an aqueous solution with pH=7. In 2009, Kudo A et al. published a review entitled "Heterogeneous photocatalytic materials for water splitting" in Chemical Society Reviews. In this review, the authors summarized heterogeneous photocatalyst materials for water splitting, which guided the design of efficient and stable photocatalyst. In 2010, Craig L. Hill et al. Since then, researchers have been keen to synthesize efficient, cheap and stable photocatalysts.