Catalytic activity of gold for the electrochemical reduction of p-nitrophenol: analytical application

Abstract

ABSTRACT Para-nitrophenol (PNP) is a toxic compound that enters the environment during manufacturing and processing of a variety of industrial products. In this work, we present a study on the electrocatalytic reduction of PNP to p-hydroxyl aminophenol in aqueous solutions using metallic gold electrode. p-Hydroxyl aminophenol has been used abundantly as a model substance to check the catalytic activity of metallic gold electrode. Here, we present a full kinetic scheme that includes the intermediate p-Hydroxyl aminophenol. The discussion of the resulting kinetic equations shows that the reduction of PNP at the surface of metallic gold electrode is a diffusion transfer process and irreversible. The analytical performance was also evaluated with respect to PNP concentration, and other variables. A linear calibration graph was obtained in the concentration range from 5.0 × 10−7 to 5.0 × 10−3 mol L−1 PNP. The detection limit was found to be 5.0 × 10−7 mol L−1. For eight tests, the differential pulse response was reproduced with 1.9% relative standard deviation at 5.0 × 10−6 mol L−1 PNP in acetate buffer solution.