Ciência e Engenharia de Materiais: conceitos, fundamentos e aplicação
2021
A thin film with phosphotungstate nanoclusters: an alternative to materials scientists investigate the electroreduction of hexazinone
VICTÓRIA DE OLIVEIRA MARGARIDO; PEDRO HENRIQUE DE PAULO OLÍVIO; LEONARDO APARECIDO CORREIA; JULIA HELENA DE PAULA; KELLY ROBERTA FRANCISCO; ADRIANO LOPES DE SOUZA

Abstract

In the work reported here, we investigated the surface topography and the electrocatalytical ability toward hexazinone herbicide of a hybrid organically modified silicate (ormosil) film using (3-aminopropyl)triethoxysilane and phosphotungstic acid (HPW), a polyoxometalate (POM) nanocluster. The morphology of the film on gold electrode was studied with a recent surface analysis technique based on atomic force microscopy coupled with infrared absorption spectroscopy. This hybrid ormosil film showed nanopores distributed throughout the surface and the interaction between HPW clusters and amine groups was electrostatic. The electrocatalytic reduction of hexazinone occurred at −0.20 V vs. Ag/AgCl in acidic medium pH 0.80 as shown by cyclic voltammetry analyses. Solid state 29Si nuclear magnetic resonance analyses showed that the distribution of silicate groups in the ormosil is formed by Q3 and Q4 species. Since a sensor for hexazinone was not aimed here, this system studied can contribute to the improvement of useful materials in environmental science research.

Keywords: Sol-gel Process: Ormosil; Hexazinone; Hybrid Film; Phosphotungstic Acid.