An isolated doughnut-like molybdenum(V) cobalto-phosphate cluster exhibiting excellent photocatalytic performance for carbon dioxide conversion.

An isolated doughnut-like molybdenum(V) cobalto-phosphate cluster with the formula (C 11 NH 10 ) 2 {[Co(H 2 O) 6 ]@[H 29 Co 16 Mo 16 (H 2 O) 16 (PO 4 ) 24 O 36 ]}(H 2 PO 4 )·25H 2 O has been successfully synthesized by a hydrothermal method. Single crystal X ray diffraction analysis shows that four {Co 4 O 60 } tetramers and eight {Mo 2 O 10 } dimers are linked by oxygen atoms and phosphate groups to construct a doughnut-type structure for [Co@{Co 16 Mo 16 }], in which one [Co II (H 2 O) 6 ] 2+ octahedron is enclosed. More importantly, [Co@{Co 16 Mo 16 }] exhibits promising photocatalytic performance for CO 2 reduction with the CO formation rate of 6764.3 μmol g -1 h -1 and the selectivity of 96.89%. In addition, the cycling test indicated that [Co@{Co 16 Mo 16 }] can be reused for at least four cycles without significant loss of catalytic activity. The result of this work may provide new insight for the synthesis of highly efficient POM-based photocatalysts for CO 2 reduction.