Morphological and electrochemical characterizations of a carbon nitride/highly oriented pyrolytic graphite electrode

Abstract

• The size distribution of g-C 3 N 4 exfoliated particles in suspension was studied. • The morphology, texture, thickness and covered area of the film were analyzed. • Different microscopy techniques were employed in the surface studies. • Electrochemical characterization of the surface were performed. • For HPRR, TOF parameter of electroactive sites on HOPG/ g-C 3 N 4 was estimated. In the present work, we present a complete study about morphology and electrochemical properties of graphite carbon nitride (g-C 3 N 4 )/highly oriented pyrolytic graphite (HOPG) electrode surface for hydrogen peroxide reduction reaction (HPRR). First, the size distribution of exfoliated g-C 3 N 4 particles in suspension was studied. By drop-casting technique, the film on the HOPG surface was deposited and the size distribution of conglomerates on the surface was studied. Different microscopy and image processing techniques were combined to analyse the surface landscape. Properties like morphology, texture, thickness, local composition and covered area by the discontinuous film were also analysed. By electrochemical techniques surface properties like wetting area and roughness factor were determined. For HPRR the electroactive area, number and types of active sites and their rotation frequency were studied. These studies suggest that g-C 3 N 4 is a useful electroactive material for HPRR, which can be used to enhance the electro-activity of other cheaper carbonaceous substrates.