Enhanced degradation of venlafaxine induced by Fe2O3/CeO2 2 O 3 /CeO 2 heterostructures through the thermal transformation from type I to direct Z-scheme in heterogeneous photo-Fenton

Author(s)

Ayala-Duran, Saidy C. ; Rojas-Mantilla, Hernan D. ; Perez-Moya, Montserrat ; Nogueira, Raquel F. Pupo

• Document type: Journal article
• Source: JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING; v. 12, n. 6, p. 19-pg., 2024-10-17.

Abstract

Heterostructures based on Fe2O3/CeO2 2 O 3 /CeO 2 were synthesized by coprecipitating iron and cerium salts, with 70 % and 50 % atomic percentage of iron, and heat treatment at 600 and 800 degrees C (Fe70Ce600, Fe50Ce600, Fe70Ce800, Fe50Ce800). The catalytic activity in the Fenton and photo-Fenton process was evaluated in the degradation of venlafaxine (VEN) using UV/Vis LEDs. Treatment at 800 degrees C promoted greater crystallinity, increased crystallite size, decreased specific area, and high absorption between 200 and 600 nm, and bandgap energy (Eg) g ) between 1.6 and 3.0 eV were observed. The heat treatment promoted different mechanisms in heterostructure materials with type I (straddling) schemes for Fe70Ce600 and Fe50Ce600, type II for Fe50Ce800, and direct Z for Fe70Ce800 responsible for generating a higher concentration of HO center dot radicals, high oxidation-reduction power (---Fe2+/---Fe3+) - -- Fe 2+ / - -- Fe 3+ ) and (---Ce4+/---Ce3+), - -- Ce 4+ / - -- Ce 3+ ), greater effective separation of charge carriers, providing improved catalytic activity due to the synergy between heterogeneous photocatalysis and photo-Fenton processes. LC-MS/MS analysis identified 12 transformation products (TPs), involving hydroxylation reactions, demethylation, and loss of cyclohexanol. The transformation products TP2 and TP9 were exclusive to Fe70Ce800, confirming different mechanisms among the heterostructures. (AU)

• FAPESP's process: 18/12780-4 - Innovative decentralized and low cost treatment systems for optimal urban wastewater management
• Grantee: Raquel Fernandes Pupo Nogueira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 24/04167-1 - Filtration membranes modified with semiconductors to build heterogeneous filtration/photocatalysis hybrid systems.
• Grantee: Hernan Dario Rojas Mantilla
• Support Opportunities: Scholarships in Brazil - Post-Doctoral