SnO2/reduced graphene oxide composite films for electrochemical applications

• SnO2/GO composites with mass fraction of carbon phase 0.01% ≤ wC ≤ 80% have been formed.
• 400 °C annealing was applied for GO reduction in the composites.
• SnO2/rGO composites demonstrate a high electrocatalytic activity in anodic processes.
• Exchange current density grows linearly with carbon phase concentration at wC ≤ 10%.

SnO2/GO (GO is graphene oxide) composite films with GO mass fraction wC ranging from 0.01 to 80% have been prepared using colloidal solutions. Heat treatment of SnO2/GO films in Ar atmosphere at 400 °C leads to GO reduction accompanied by partial exfoliation and decreasing of the particle thickness. SnO2/rGO (rGO is reduced GO) film electrodes demonstrate a high electrocatalytic activity in the anodic oxidation of inorganic (iodide-, chloride-, sulfite-anions) and organic (ascorbic acid) substances. The increase of the anodic current in these reactions is characterized by overpotential inherent to the individual rGO films and exchange current density grows linearly with rGO concentration at wC ≤ 10% indicating that the rGO particles in composites act as sites of electrochemical process. The SnO2/rGO composite films, in which the chemically stable oxide matrix encapsulates the rGO inclusions, can be considered as a promising material for applied electrochemistry.