Integration of a photoelectrochemical cell in a flow system for quantification of 4-aminophenol with titanium dioxide

Author(s)

Mendonca, Camila D. ^{[1, 2]} ; Rahemi, Vanoushe ^[1] ; Hereijgers, Jonas ^[3] ; Breugelmans, Tom ^{[3, 4]} ; Machado, Sergio A. S. ^[2] ; De Wael, Karolien ^{[1, 5]}

Affiliation

^[1] Univ Antwerp, AXES Res Grp, Groenenborgerlaan 171, B-2020 Antwerp - Belgium

^[2] Univ Sao Paulo, Inst Chem Sao Carlos, IQSC USP, Av Trabalhador Sao Carlense 400, Sao Carlos, SP - Brazil

^[3] Univ Antwerp, ELCAT Res Grp, Univ Pl 1, B-2610 Antwerp - Belgium

^[4] VITO, Separat & Convers Technol, Boeretang 200, B-2400 Mol - Belgium

^[5] Univ Antwerp, NanoLab Ctr Excellence, Groenenborgerlaan 171, B-2020 Antwerp - Belgium

• Document type: Journal article
• Source: Electrochemistry Communications; v. 117, AUG 2020.
• Web of Science Citations: 0

Abstract

The photoelectrochemical quantification of phenolic compounds such as hydroquinone (HQ) and 4-aminophenol (4-AP) is accomplished by integrating a photoelectrochemical cell into a flow injection analysis (FIA) setup. It is a well-known fact that during the electroanalysis of phenolic compounds, the electrode surface is susceptible to poisoning. However, electrode fouling can be reduced significantly by using the FIA system with periodic washing of the electrode. Reactive oxygen species (ROS), which are generated on the surface of TiO2 under UV light, can oxidize phenolic compounds such as 4-AP. The oxidized form of 4-AP is reduced back at the electrode surface, generating a measurable signal proportional to its concentration. The factors influencing the perfor-mance of the sensor, such as flow rate, applied potential for back reduction and pH, are investigated in detail. In the concentration range 0.0125-1.0 mu M, a linear correlation between the photocurrent and the concentration of 4-AP was observed with a sensitivity of 0.6 A M-1 cm(-2) and a limit of detection of 18 nM. A straightforward analytical methodology for the on-site, highly sensitive and low-cost quantification of phenolic compounds is presented, based on the use of TiO2 in a photoelectrochemical flow cell. (AU)

• FAPESP's process: 18/13724-0 - Development of a photoelectrochemical sensor for the quantification of phenolic contaminants
• Grantee: Camila Domingues Mendonça Verbinnen
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate