Highly Branched RuO2 Nanoneedles on Electrospun TiO2 Nanofibers as an Efficient Electrocatalytic Platform

Abstract

Highly single-crystalline ruthenium dioxide (RuO<inf>2</inf>) nanoneedles were successfully grown on polycrystalline electrospun titanium dioxide (TiO<inf>2</inf>) nanofibers for the first time by a combination of thermal annealing and electrospinning from RuO<inf>2</inf> and TiO<inf>2</inf> precursors. Single-crystalline RuO<inf>2</inf> nanoneedles with relatively small dimensions and a high density on electrospun TiO<inf>2</inf> nanofibers are the key feature. The general electrochemical activities of RuO<inf>2</inf> nanoneedles-TiO<inf>2</inf> nanofibers and Ru(OH)<inf>3</inf>-TiO<inf>2</inf> nanofibers toward the reduction of [Fe(CN)<inf>6</inf>]3- were carefully examined by cyclic voltammetry carried out at various scan rates; the results indicated favorable charge-transfer kinetics of [Fe(CN)<inf>6</inf>]3- reduction via a diffusion-controlled process. Additionally, a test of the analytical performance of the RuO<inf>2</inf> nanoneedles-TiO<inf>2</inf> nanofibers for the detection of a biologically important molecule, hydrogen peroxide (H<inf>2</inf>O<inf>2</inf>), indicated a high sensitivity (390.1 ± 14.9 μA mM-1 cm-2 for H<inf>2</inf>O<inf>2</inf> oxidation and 53.8 ± 1.07 μA mM-1 cm-2 for the reduction), a low detection limit (1 μM), and a wide linear range (1-1000 μM), indicating H<inf>2</inf>O<inf>2</inf> detection performance better than or comparable to that of other sensing systems. © 2015 American Chemical Society.