Hydrogen peroxide monitoring in photo-Fenton reactions by using a metal hexacyanoferrate modified electrode

A sensitive sensor for the determination of hydrogen peroxide was fabricated based on the enhanced response of the analyte at glassy carbon surfaces modified by a film of Co(II) hexacyanoferrate. Increased chemical stability of the film was gained by incorporation of ruthenium (III) ions. Following the optimization of the experimental conditions for the film deposition, the RuCoHCF modified electrode presented excellent analytical properties toward hydrogen peroxide with a low limit of detection (2.8 mmol L-1), a large dynamic concentration range (10 – 500 mmol L-1) and a very short response time (t100% = 6.3 s for 0.02 mmol L-1 hydrogen peroxide). The usefulness of the proposed RuCoHCF electrochemical sensor was confirmed by monitoring the consumption of hydrogen peroxide during photodegradation reactions of an azo dye compound (Remazol Black B) present in wastewater samples.