Amperometric detection of nitrite using Co3O4 thin film

Abstract

In this MSc thesis, Co3O4 thin film was prepared by metal-organic decomposition on FTO substrate and hydrothermal treatment in the presence of L-Arginine. The conditions for hydrothermal treatment were optimized with respect to time, temperature, L-Arginine concentration, and pH. The L-Arginine-treated Co3O4 thin film (L-Arginine/Co3O4/FTO) was used for the electrochemical detection of nitrite under neutral pH condition. Several physical (i.e., XRD, XPS, SEM, and Raman spectroscopy) and electrochemical (i.e., CV, CA, and EIS) techniques were used to elucidate the role and effect of L-Arginine on Co3O4 film as well as to determine the sensor performance. It is demonstrated that the L-Arginine-treated electrode exhibited enhanced electrochemical nitrite detection compared to pristine Co3O4 electrode. The proposed nitrite sensor also showed a combination of ultralow limit of detection (1.95 nM), fast response time (< 2 s), wide linear range (10 – 16 000 μM), high sensitivity (158 μM/mM.cm-2) and selectivity compared to the reported literature.