Cerium oxide is an important technological materials and widely used in catalytic converters in automobiles, solid oxide fuel cells, and fuel additives, etc. Recently, it has been discovered that Nanoceria has the ability to kill cancer cells. In addition, it is found that nanoceria can mimic superoxide dismutase (SOD) and catalase activities both of which are essentially the enzymes in the body that are responsible for disproportion of superoxide and peroxide respectively. All of the previously stated applications use the dynamic nature of valence states transition in Nanoceria and makes it electrochemically active. This study is specifically designed to measure nanoceria’s redox potential associated with its transition in biological media to fine-tune its further applications. In biological media, the pH also affects the transition characteristics in nanoceria. It is imperative to measure potential-pH diagram for nanoceria as well. In this study we propose to find redox potential of cerium oxide exposed to various pH by the use electrodes made up of nanoceria embedded onto platinum and nickel mesh substrates. Redox reactions are monitored by using cyclic voltammetry experiments. The redox potential of different ceria synthesis is compared at various pHs. Surfaces of Nanoceria are characterized using SEM, XPS and TEM. A complete picture of potential-pH diagram of Nanoceria is presented.