Pt-Substituted polyoxometalate modification on the surface of low-cost TiO2with highly efficient H2evolution performance

In this study, Pt-substituted polyoxometalate was first modified on the surface of commercially available TiO2, forming an efficient photocatalyst with high reactivity for hydrogen evolution. During the photocatalytic process, Pt-polyoxometalates not only increase the mobility rate of electrons but also improve the separation efficiency of photoinduced electrons and holes. After photoreduction, the in situ generated Pt0 species are anchored on the surface of polyoxometalate anion, which prevents further agglomeration. Then, the in situ formed Pt0 species and polyoxometalates synergistically promote the efficiency of photoinduced electron transfer from TiO2 to the protons adsorbed on the Pt0 surface. Although the content of Pt0 in the nanocomposite is only 0.6%, the photocatalytic hydrogen production rate reaches 5.6 mmol g-1 h-1 and remains stable at 4.5 mmol g-1 h-1 after the continuous catalytic process. Due to the modification of TiO2 by Pt-substituted polyoxometalate, this nanocomposite represents a practical model that possesses highly efficient photoelectric conversion performance. The presented work not only extends the family of new TiO2-polyoxometalate-based materials but also takes a further step toward the practical application of commercial TiO2 in photocatalytic hydrogen production.