RuO2–ReO3 composite nanofibers for efficient electrocatalytic responses

Abstract

We present a facile synthetic route to ruthenium dioxide (RuO₂)–rhenium oxide (ReO₃) electrospun composite nanofibers and their electrocatalytic responses for capacitance and H₂O₂ sensing. The contents of rhenium oxide of electrospun ruthenium dioxide (RuO₂) were carefully controlled by an electrospinning process with the preparation of the precursor solutions followed by the thermal annealing process in air. The electrochemical applications of RuO₂–ReO₃ electrospun composite nanofibers were then investigated by modifying these materials on the surface of glassy carbon (GC) electrodes, RuO₂–ReO₃(n)/GC (n = 0.0, 0.07, 0.11, and 0.13), where n denotes the relative atomic ratio of Re to the sum of Ru and Re. Specific capacitance and H₂O₂ reduction sensitivity were remarkably enhanced depending on the amount of ReO₃ increased. Among the four compositions of RuO₂–ReO₃(n), RuO₂–ReO₃(0.11)/GC showed the highest performances, i.e., a 20.9-fold higher specific capacitance (205 F g⁻¹ at a potential scan rate (v) of 10 mV s⁻¹; a capacity loss of 19% from v = 10 to 2000 mV s⁻¹) and a 7.6-fold higher H₂O₂ reduction sensitivity (668 μA mM⁻¹ cm⁻², normalized by GC disk area), respectively, compared to only RuO₂/GC.