Synthesis of two-dimensional polyoxoniobate-based clusterphenes with in-plane electron delocalization

Two-dimensional (2D) materials offer unique platforms for exploring electronic structures and catalytic applications. Nanoclusters, referred to as ‘superatoms’, can be directly connected to construct 2D nanostructure networks. Here eight kinds of 2D clusterphenes are prepared by assembling polyoxoniobate (PONb) clusters with transition or rare-earth metal ions through a facile wet-chemical synthesis at room temperature. Monolayer and few-layer PONb-clusterphenes with hexagonal structures are constructed by the direct bonding of C 3 v symmetric {Nb 24 O 72 } clusters. The PONb-clusterphenes show enhanced photocatalytic activity for benzyl alcohol oxidation, with a conversion rate ten times greater than that of the PONb cluster units. Theoretical investigations suggest this is because of a reduction in the reaction energy barrier due to the in-plane electron delocalization of the PONb-clusterphenes. The constructed 2D PONb-clusterphenes with hexagonal arrangement and unique electronic properties provide an atomically precise model with which to study the electronic structures of cluster-based assemblies in heterogeneous catalysis.