Elucidation of the atrazine degradation intermediates and dependence on the physicochemical properties of the niobium pentoxide nanostructures

Atrazine (ATZ) is a toxic herbicide used globally and has been found with its by-products in different environmental ecosystems. Due to these by-products toxicity, the scientific community has endeavored to seek technologies capable of removing them from the aquatic ecosystem, as well as finding alternatives to unravel the reaction mechanisms. The Nb2O5 semiconductor was obtained in this study by the hydrothermal method aiming at the ATZ degradation under UV light. A volume of 70 mL of 5 mg L-1 ATZ solution containing 10 mg of catalyst, and natural pH achieved 70% photocatalytic degradation of ATZ in 30 min under UV light, which represents an improvement of up to 46% compared to photolysis. After the ATZ degradation, the intermediates were monitored efficiently by molecular absorption spectrometry and hydrogen nuclear magnetic resonance (H-1 NMR) to reveal the chemical nature of these compounds. Hydroxyatrazine (HAT), Desethylatrazine (DEAT), and/or Desisopropylatrazine (DIAT) were suggested based on the analytical data, allowing to unveil the ATZ photocatalytic degradation mechanism mediated by Nb2O5 under UV light. Therefore, the results present in this study confirm an alternative for ATZ environmental remediation and the molecular absorption spectrometry and H-1 NMR applicability to intermediates identification, which is essential to unravel the ATZ degradation mechanisms.