Influence of phosphorus doping level and acid pretreatment on the voltammetric behavior of phosphorus incorporated tetrahedral amorphous carbon film electrodes

Phosphorus incorporated tetrahedral amorphous carbon (ta-C:P) films are prepared by filtered cathodic vacuum arc technology with phosphine as the dopant. The influence of phosphorus doping level and acid pretreatment on the electrochemical properties of ta-C:P electrodes is investigated by cyclic voltammetry, Raman spectroscopy and X-ray photoemission spectroscopy. Results indicate that phosphorus incorporation improves the electrical and electrochemical behaviors of the films. A moderate phosphorus atomic fraction facilitates the interfacial electron transport in context of a high content of effective phosphorus impurities. Furthermore, acid pretreatment activates the surface of the films and gives an excellent reversible feature towards ferricyanide oxidation reaction by removing the inactive oxygenated sites and exposing the active conduction channels.