Fig. 5

Effect of Cu2+ concentration at pH 2: a temporal reduction of Cr6+; b response in the current density. Effect of Cu2+ concentration at pH 4: a temporal reduction of Cr6+; b response in the current density
Effect of Cu2+ concentration at pH 2: a temporal reduction of Cr6+; b response in the current density. Effect of Cu2+ concentration at pH 4: a temporal reduction of Cr6+; b response in the current density