Self-Assembled 8-Ti-Containing Polyoxomolybdate for the Photocatalytic Hydrogen Evolution

Abstract

An S-shaped 8-Ti-containing polyoxomolybdate (NH 4 )-Cs 2 Na 6 H 3 [Ti 8 (GeMo 9 O 34 ) 2 (GeMo 5 O 23 ) 2 ]•44H 2 O (1) has been prepared under the one-pot hydrothermal method and further characterized. According to single-crystal X-ray, compound 1 consists of two {GeMo 9 O 34 } and two {GeMo 5 O 23 } segments, which are linked with a {Ti 8 O 34 } cluster. Moreover, the {GeMo 5 O 23 } fragment is rare and the first discovery, which enriches the lacunary Keggin-type family and offers the possibility of obtaining new structures. Among all of the reported polyoxomolybdates, compound 1 has the highest nuclearity of Ti centers. From the photocatalytic hydrogen evolution studies, compound 1 can be used as the heterogeneous catalyst with an H 2 evolution rate of 2392.6 μmol g −1 h −1 under minimally optimized conditions.