Synthesis of silver/nitrogen-doped reduced graphene oxide through a one-step thermal solid-state reaction for oxygen reduction in an alkaline medium

• Published in: Journal of power sources 2016-08, Vol.324, p.412-420
• Main Authors: Soo, Li Ting, Loh, Kee Shyuan, Mohamad, Abu Bakar, Daud, Wan Ramli Wan, Wong, Wai Yin
• Format: Article
• Language: English
• Subjects: Alkaline medium; Graphene; Methyl alcohol; Oxides; Oxygen reduction; Platinum; Reduced graphene oxide; Silver; Silver/nitrogen-doped; Transmission electron microscopy; Voltammetry; X-ray photoelectron spectroscopy
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2016.05.106

One of the obstacles to the commercialisation of fuel cells is the high cost of noble metals, such as platinum, that are used as electrocatalysts. Silver-incorporated nitrogen-doped reduced graphene oxide (Ag/N-rGO) has been synthesised through the simple annealing of metal salts with graphene oxide and melamine. The presence of silver and nitrogen atoms in Ag/N-rGO was confirmed by X-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS) analysis. Both the XPS and EDS results showed a higher Ag loading on the N-rGO surface compared with the rGO surface. Transmission electron microscopy (TEM) images revealed a wide size distribution of Ag particles loaded on the N-rGO surface. Electrochemical results indicate that N-rGO is a better support for Ag than rGO. Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) results indicate that Ag/N-rGO is a potential ORR catalyst candidate in alkaline as it exhibited an onset potential of −0.15 V vs. Ag/AgCl and a limiting diffusion current density of −4.38 mA cm−2 with four electron pathways. In addition, Ag/N-rGO also showed better methanol tolerance than Pt/C. [Display omitted] •Facile synthesis of Ag/N-rGO catalyst via a solid-state thermal method.•The ORR performance of Ag/N-rGO catalyst was evaluated by CV and RRDE.•The synergism effect of the Ag/N-rGO catalyst towards ORR was discussed.•N-rGO support provides active sites for metal deposition and ORR.