A novel polyoxometalate-based metal–organic nanotube framework templated by twin-Dawson clusters: synthesis, structure and bifunctional electrocatalytic properties

A novel polyoxometalate-based metal-organic framework templated by twin-Dawson clusters, [{Cu-3(mu(3)-O)}(2)(trz)(6)Cu-2(H2O)(13)][H1.73P2As1.73W16.27O62]center dot 8.25H(2)O (1) (trz = 1,2,4-triazole), has been synthesized under hydrothermal conditions. In 1, there are two crystal distinct motifs: a 3D metal-organic nanotube framework and seven-connected Dawson clusters. It is worth mentioning that the 3D framework possesses nanotube-like channels. The twin-H1.73P2As1.73W16.27O62 clusters (abbreviated as P-2(As/W)(18) clusters) as templates occupy channels of the nanotube framework. To the best of our knowledge, this represents the first metal-organic nanotube framework templated by twin-Dawson clusters. The electrochemical experiments indicate that the 1-based glassy carbon electrode (1-GCE) possesses high catalytic efficiency and high stability toward reduction of inorganic bromate molecules and oxidation of the biological molecule ascorbic acid. The electrocatalytic efficiency towards the reduction of bromate in 1 M H2SO4 solution and oxidation of AA in N-2 purged solution is ca. 848.4% and 896.8% (catalytic substrate: 0.5 mM), respectively. The current signal after 100 cycles exhibits almost no loss for 1-GCE.