Enhanced electrochemical reactions at hierarchical nanoporous indium tin oxide based on self-assembly of nanocubes.

• A new strategy for fabricating hierarchical nanoporous electrodes by self-assembly of edge-truncated, monodisperse ITO nanocubes as building blocks. • Small self-assembled clusters of nanocubes created small uniform pores between edges. • Random aggregation of the clusters created larger pores. • Nanoporous ITO exhibited enhanced electron-transfer kinetics and electrocatalytic activity. The enhanced catalytic activity of the nanoporous electrodes with small and uniform pores is caused by structural effects and represents a significant breakthrough in catalysis research. Herein, a new strategy for fabricating hierarchical nanoporous electrodes is presented. Nanoporous electrodes were constructed by self-assembly using indium tin oxide (ITO) nanocube as building blocks. The self-assembly of nanocubes created small and uniform pores between edges, and random aggregation of the small self-assembled clusters readily created a multimodal structure. It was observed that the simple one electron-transfer reaction of Fe ions was greatly improved at the ITO nanoporous electrodes when compared with the flat ITO electrode. Such enhancement is a result of improved reactivity through small pores and rapid mass transfer through large pores. Furthermore, it was confirmed that the catalytic activity of the ascorbic acid reaction increased when using these nanoporous electrodes. These findings provide insight into the fabrication of nanoporous electrodes and their potential use as catalysts. [Display omitted] [ABSTRACT FROM AUTHOR]