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

A facile hydrothermal synthetic method, followed by in situ reduction and galvanic replacement processes, is used to prepare PtCo-modified Co 3 O 4 nanosheets (PtCo/Co 3 O 4 NSs) supported on Ni foam. The prepared nanomaterial is used as an electrocatalyst for NaBH 4 oxidation in alkaline solution. The morphology and phase composition of PtCo/Co 3 O 4 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/Co 3 O 4 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/Co 3 O 4 and PtCo/Co 3 O 4 NSs, respectively, in a solution containing 2 mol·L –1 NaOH and 0.2 mol·L –1 NaBH 4 . The use of a noble metal (Pt) greatly enhances the catalytic activity of the transition metal (Co) and Co 3 O 4 . Besides, both Co and Co 3 O 4 exhibit good B–H bond breaking ability (in NaBH 4 ), which leads to better electrocatalytic activity and stability of PtCo/Co 3 O 4 NSs in NaBH 4 electrooxidation compared to pure Pt. The results demonstrate that the as-prepared PtCo/Co 3 O 4 NSs can be a promising electrocatalyst for borohydride oxidation.