The Origin of High Electrocatalytic Activity of Hydrogen Peroxide Reduction Reaction by g-C3N4/HOPG Sensor

SILVA, ALEXANDER MARTIS; ROJAS, MARIANA ISABEL; GOMEZ, CESAR; AVALLE, LUCIA; STRUMIA, MIRIAM C.

Nanoscale

Royal Society of Chemistry

Lugar: Berlin; Año: 2017 vol. 9 p. 11170 - 11179

2040-3364

Graphitic carbon nitride (g-C3N4) was synthesized from a low-cost precursor by means of a thermal process. The product was characterized by several spectroscopic techniques and crystallinity was analyzed by X-ray diffraction. In the manufacture of the sensor, the g-C3N4 was chemically exfoliated and a film was placed on the surface of a Highly Oriented Pyrolytic Graphite (HOPG). We compared the electrocatalytic activities of g-C3N4/HOPG and pristine HOPG surfaces as sensors for H2O2 quantification in buffer solution at pH 7. Results indicate that the surface of g-C3N4/HOPG exhibits striking analytical stability as well as reproducibility, enabling a reliable and sensitive determination within 0.12 - 120 μM interval with a detection limit of 0.12 μM. These results suggest that this g-C3N4 film is a really particularly good nanostructured material to be applied as biosensor. Chemical and physical factors are responsible for the outstanding electrocatalytic activity observed. The N in the g-C3N4 allows huge uptake of H2O2 through hydrogen-bonding interaction and the change in the electronic structure since HOPG/g-C3N4 heterojunction favors the charge transference process through the interface.