We have succeeded in studying primary free radical reactions towards reduced graphene oxide (RGO) using pulse radiolysis technique. The ability of RGO to quench hydrated electron, e(aq)(-), can be visualized as a process to store electrons. Low reactivity of (OH)-O-center dot and (SCN)(2)(center dot-) radicals towards RGO shows that coxidation process can be minimized at the surface of RGO. Moreover, it is found that methyl viologen radical also shows low reactivity towards RGO. Further, using RGO as a two-dimensional support, transient absorption spectra of Ag clusters show that stabilization of Ag-2(+) cluster occurs at the surface of RGO as compared to neat aqueous solution. (C) 2012 Elsevier B. V. All rights reserved.