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 (CNH){[Co(HO)]@[HCoMo(HO)(PO)O]}(HPO)·25HO has been successfully synthesized by a hydrothermal method. Single crystal X ray diffraction analysis shows that four {CoO} tetramers and eight {MoO} dimers are linked by oxygen atoms and phosphate groups to construct a doughnut-type structure for [Co@{CoMo}], in which one [Co(HO)] octahedron is enclosed. More importantly, [Co@{CoMo}] exhibits promising photocatalytic performance for CO reduction with the CO formation rate of 6764.3 μmol g h and the selectivity of 96.89%. In addition, the cycling test indicated that [Co@{CoMo}] 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 reduction.