Low-cost and binder-free, paper-based cobalt electrode for sodium borohydride electro-oxidation.

A low-cost and binder-free cobalt electrode is prepared by the electrodeposition of Co nanoplates onto a flexible conductive substrate, which is prepared simply by scratching a piece of A4 paper with a common 8B pencil. The morphology and phase structure of the cobalt–graphite–paper (CGP) electrode are characterized by scanning electron microscopy, transmission electron microscopy and an X-ray diffractometer. The catalytic activity of the CGP electrode for NaBH₄ electro-oxidation is investigated by cyclic voltammetry and chronoamperometry. The catalyst combines tightly with the paper and exhibits a good stability. The oxidation current density reaches up to 180 mA cm⁻² in 1 mol dm⁻³ NaOH and 0.10 mol dm⁻³ NaBH₄ at −0.4 V. [ABSTRACT FROM AUTHOR]