Composites of graphene (oxide) (GO) and first‐row transition‐metal cations (Co2+, Ni2+, Mn2+, Fe2+) are prepared by mixing GO and aqueous metal salt solutions. The amount of metal cation bound to GO nanosheets is calculated by using inductively co...
Composites of graphene (oxide) (GO) and first‐row transition‐metal cations (Co2+, Ni2+, Mn2+, Fe2+) are prepared by mixing GO and aqueous metal salt solutions. The amount of metal cation bound to GO nanosheets is calculated by using inductively coupled plasma mass spectrometry (ICP‐MS) and the possible binding sites of the metals are investigated by means of attenuated total reflectance infrared (ATR‐IR) spectroscopy and X‐ray photoelectron spectroscopy (XPS) measurements. Electrodes loaded with the metal/GO composites are prepared by a simple drop‐casting technique without any binders or conductive additives. The effect of electrochemical reduction on the structure of the composite electrodes is investigated by Raman spectroscopy, XPS, X‐ray diffraction (XRD) analysis, and field emission scanning electron microscopy (FESEM). A detailed electrochemical characterization is performed for the utilization of the composite electrodes for electrochemical capacitors and possible oxygen reduction reaction electrocatalysts by cyclic voltammetry (CV) and rotating disk electrode measurements. The highest areal capacitance is achieved with the as‐deposited Fe/GO composite (38.7 mF cm−2 at 20 mV s−1). In the cyclic stability measurements, rCo/GO, rNi/GO, rMn/GO, and rFe/GO exhibit a capacitance retention of 44, 1.1, 73, and 87 % after 3000 cycles of CV at 100 mV s−1, respectively.
Metal dictation: Graphene oxide–metal composites are produced by the utilization of simple electrostatic interactions. Changes in the structure of graphene oxide with the addition of metal cations are investigated. The nature of the metal cation is highly influential on the final electrochemical characteristics of the composites (see figure).