Stable and highly efficient Co–Bi nanoalloy decorated on reduced graphene oxide (Co–Bi@rGO) anode for formaldehyde and urea oxidation reactions

Abstract

Extremely energetic and low-cost novel nanoelectrodes for fuel cell reactions are always important for examining more elaborative electrochemical studies at interfacial electron transfer reactions. Herein, this work demonstrated a bifunctional electrocatalyst with its oxophilic character and promoting the role of p-electrons of Bi to be supported with Co (nanoalloy) and further decoration on reduced graphene oxide i.e. Co–Bi@rGO presenting as an auspicious electrochemical activity towards formaldehyde and urea oxidation reactions. Synthesized Co–Bi@rGO composite have been well characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), BET surface area measurement, and X-ray photoelectron spectroscopy (XPS) studies, etc. Further, the electrochemical evaluation shows exceptionally higher activity towards formaldehyde and urea oxidation reactions having onset potential of 0.32 V, 0.35 V vs. SCE respectively. Interestingly, ultra-high enhancement factor for Co–Bi@rGO could be initiated from the cooperative role of Bi with Co centres, assisting for formaldehyde and urea oxidation reactions. Electrochemical impedance spectroscopy (EIS) and chronoamperometry (i-t) studies using Co–Bi@rGO nanocomposite shows excellent long-term current/potential stability with lower charge transfer resistance towards the formaldehyde and urea molecules. This work deals with practical information for the build of a stable and proficient electrocatalyst for direct formaldehyde and urea fuel cells and also will extendable towards the industrial waste water treatment.