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

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 demon-strated 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, assist-ing for formaldehyde and urea oxidation reactions. Electrochemical impedance spectroscopy (EIS) and chro-noamperometry (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.

Automated summary

This study developed novel nanoelectrodes that are highly energetic and low-cost, which are important for examining interfacial electron transfer reactions. The researchers demonstrated a bifunctional electrocatalyst with oxophilic character and promoting the role of p-electrons of Bi, supported with Co (nanoalloy), and decoration on reduced graphene oxide. The Co-Bi@rGO composite showed auspicious electrochemical activity towards formaldehyde and urea oxidation reactions, with exceptionally higher activity and stability. The findings provide practical information for the development of stable and efficient direct formaldehyde and urea fuel cells and wastewater treatment.