A new octamolybdate-based coordination polymer for light-driven hydrogen evolution

• A new octamolybdate-based hybrid compound with an intriguing layer structure. • Facilitating electron transportation between Cu-pzta and octamolybdate subunits. • Effectively improving the photocatalytic performance of pure POMs. • Showing high photocatalytic hydrogen productivity (330.44 μmol −1 g −1 h −1 ). A new octamolybdate-based metal–organic compound [Cu II 2 (bibe)(pzta) 2 ][H 2 Mo 8 O 26 ] ( Cu II 2 -Mo 8 , bibe = 4,4’-bis(imidazolyl)biphenyl, pzta = 3-(pyrid-4-yl) pyrazole) was obtained by hydrothermal reaction technology and characterized by sufficient methods including IR, PXRD, luminescence spectroscopy, XPS and single crystal X-ray diffraction measurements. The compound possesses a two dimensional (2D) structural motif. Such structure feature is beneficial to electron transportation between Cu-pzta complexes and octamolybdate clusters. Therefore, the compound as a new photocatalyst shows a high photocatalytic hydrogen productivity. It can reach 330.44 μmol −1 g −1 h −1 that is higher than 42.35 μmol g −1 h −1 of parent polyoxometalate (NH 4 ) 6 Mo 7 O 24 ·4H 2 O. A new octamolybdate-based metal–organic compound with an intriguing layer structure was synthesized and applied as photocatalyst showing a high photocatalytic hydrogen activity.