Uniformly grown PtCo-modified Co3O4 nanosheets as a highly efficient catalyst for sodium borohydride electrooxidation

Abstract

A facile hydrothermal synthetic method, followed by in situ reduction and galvanic replacement processes, is used to prepare PtCo-modified Co3O4 nanosheets (PtCo/Co3O4 NSs) supported on Ni foam. The prepared nanomaterial is used as an electrocatalyst for NaBH4 oxidation in alkaline solution. The morphology and phase composition of PtCo/Co3O4 NSs are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The catalytic performance of PtCo/Co3O4 NSs is investigated by cyclic voltammetry (CV) and chronoamperometry (CA) in a standard three-electrode system. Current densities of 70 and 850 mA·cm–2 were obtained at–0.4 V for Co/Co3O4 and PtCo/Co3O4 NSs, respectively, in a solution containing 2 mol·L–1 NaOH and 0.2 mol·L–1 NaBH4. The use of a noble metal (Pt) greatly enhances the catalytic activity of the transition metal (Co) and Co3O4. Besides, both Co and Co3O4 exhibit good B–H bond breaking ability (in NaBH4), which leads to better electrocatalytic activity and stability of PtCo/Co3O4 NSs in NaBH4 electrooxidation compared to pure Pt. The results demonstrate that the as-prepared PtCo/Co3O4 NSs can be a promising electrocatalyst for borohydride oxidation.