The surface property of a catalyst is influenced by the presence of different inorganic ions as well as pH of the medium. Ag/reduced graphene oxide (Ag/rGO) nanocomposite was synthesized by adopting simple solution chemistry technique using simple ultrasonication process. The influence of the specific anions like Cl-, Br-, NO3-, SO42-, CH3COO- as well as cations like Na+, NH4+, Mg2+ and Ca2+ ions on the surface charge ( zeta potential) of the nanocomposite and their effect on the photocatalytic degradation efficiency towards azo dye degradation in aqueous medium was studied. We found that the catalytic property of the nanocomposite is significantly influenced by its surface property which is a function of pH of the medium and the different inorganic ions present in the system. (C) 2017 Elsevier B.V. All rights reserved.