The synthesis, characterization, and application of a platinum modified graphite electrode (Pt/G) exemplified by chloride oxidation

• A platinum modified graphite (Pt/G) electrode was fabricated by electrodeless deposition.
• Pt/G in electrolyte was both a reversible and a polarizable electrode.
• Cyclic voltammetry could be used to determine point of zero charge in terms of pHzpc and Ez (electrocapillary maximum).
• Pt/G electrode considerably improved the electrochemical production of chlorine.
• The Pt/G electrode was effective in chloride oxidation in dilute electrolyte.

A platinum modified graphite (Pt/G) electrode was synthesized by electrodeless technique using sodium borohydride (NaBH4) as the electron donor. Cyclic voltammetry (CV) was used to investigate the electrical double layer characteristics of Pt/G in 0.17 M Na2SO4 electrolyte. The surface reactivity was studied by the electrochemical oxidation of chloride. The electrodeless process enables the deposition of Pt metallic nanoparticles of approximately 15 nm in diameter uniformly dispersed on the graphite surface. The Pt/G exhibited both polarizable and reversible electrode properties. By evaluating the current–potential responses at various applied potential and pH values, it is possible to establish the potential and pH at points of zero charge, i.e., Epzc and pHpzc, respectively. The electrochemical reaction over the Pt/G and the G electrode were studied by chloride oxidation in Na2SO4 electrolyte. Results showed that the current efficiency in terms of chlorine evolution at constant current, on the Pt/G electrode was significantly improved over the raw graphite.

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