Synthesis of silver/nitrogen-doped reduced graphene oxide through a one-step thermal solid-state reaction for oxygen reduction in an alkaline medium
By Soo, Li Ting; Loh, Kee Shyuan; Mohamad, Abu Bakar; Daud, Wan Ramli Wan; Wong, Wai Yin
Published in Journal of Power Sources
2016
Abstract
Abstract 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.