Ultrasmall Pt nanoclusters deposited on europium oxide: A newly active photocatalyst for visible-light-driven photocatalytic hydrogen evolution

In the present work, europium oxide was successfully developed as a newly active photocatalyst and used for H2 evolution with Eosin Y (EY)-sensitized photocatalytic water splitting under visible light irradiation. A series of Pt nanoclusters (NCs) deposited on europium oxide photocatalysts was fabricated by an in-situ chemical deposition method. Electrochemical analysis showed that the conduction band potential of Eu2O3 was −0.82 V (vs NHE), which was more negative than the reduction potential of H2O/H2. High-resolution transmission electron microscopy revealed that the Pt NCs had excellent dispersion and ultrasmall size (~1.81 nm). The optimal photocatalytic H2 evolution activity could be obtained by EY-sensitized 5 wt% Pt/Eu under visible light and reached 807.4 μmol in 2 h. In addition, a reasonable mechanism for the enhancing photocatalytic H2 evolution activity has been investigated and presented. This research indicates that lanthanide oxides with dye sensitization could be very promising photocatalysts for the reduction of water to H2.