Designing of Au doped TiO2 NPs as an electrocatalyst for nitrite sensor

Abstract

In the present work, a simple ionothermal protocol for the synthesis of Au doped TiO2 and its subsequent application as an electrochemical interface for the trace level electroanalytical quantification of nitrite ion has been described. The surface morphology and the composition has been described with the help of Scanning electron microscope and Energy Dispersive X-Ray techniques. Further, it has been used in the fabrication of thin film electrodes by a simple physical drop casting method. Cyclic voltammetry has been used to decipher the electrocatalytic property of the modified interface towards nitrite ions and square wave voltammetry to work in the low concentration levels of nitrite ions. The developed sensor interface revealed superior nitrite sensing performance in the dynamic concentration range from 3.3 to 120 µM with a very low experimental detection limit of 0.095 µM with a sensitivity of 0.9973. The analytical applicability of the developed interference has been validated by determining the presence of nitrite from real samples with least interference from commonly encountered foreign ions. The stability and reproducibility of the proposed interface has been studied over a period of several months and the results were found to be highly reproducible with a relative standard deviation of ± 5 %. These results show that, the proposed interface electrode display better electrocatalytic activity compared to the previously reported sensors for the electro oxidation of nitrite ions.

Keywords

• Ionothermal
• Interface
• Nitrite
• Real samples