Electrochemical generation of hydrogen peroxide using cerium oxide nanostructures supported on graphene: Synthesis, characterization, and application in wastewater treatment

Author(s)

Lima, Thays S. ; Santos, Mauro C. ; Motheo, Artur J.

• Document type: Journal article
• Source: Electrochimica Acta; v. 521, p. 8-pg., 2025-02-28.

Abstract

This study investigates the electrochemical generation of hydrogen peroxide (H2O2) using three distinct cerium oxide nanostructures-nanorods, nanospheres, and nanoparticles-supported on graphene. The nanorods and nanospheres were synthesized via the hydrothermal method, with controlled adjustments to centrifugation speed, calcination temperature, and duration to tailor their morphology. Cerium nanoparticles were prepared using a coprecipitation method. These nanostructures were employed to modify graphene and were evaluated for their performance in H2O2electrogeneration. Among them, cerium nanorods exhibited the highest H2O2pro- duction, achieving a 91 % efficiency. This superior performance can be attributed to the presence of oxidizing species (Ce3+), as identified through Raman spectroscopy, along with oxygen vacancies and enhanced surface hydrophilicity. Scanning electron microscopy (SEM) revealed that the nanorods were optimally distributed below the graphene sheets. The hydrothermal and coprecipitation synthesis methods proved effective for producing cerium oxide nanostructures with high catalytic activity. These findings highlight the potential of cerium oxide nanostructures as efficient catalysts for wastewater treatment via the electro-Fenton process. (AU)

• FAPESP's process: 22/15252-4 - Nanostructured electrocatalysts for application in direct alkaline-acid fuel cells of glycerol
• Grantee: Mauro Coelho dos Santos
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants
• FAPESP's process: 22/04561-6 - Synthesis and characterization of a ternary hybrid catalyst (Nb2O5.La2O3.CeO2) supported on graphene to act as a cathode in the removal of endocrine disruptors by advanced oxidative process electrochemical (AOPEs)"
• Grantee: Thays de Souza Lima
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 22/12895-1 - Advanced processes for the degradation of emerging pollutants: catalytic materials, electroanalytical sensors and scientific dissemination
• Grantee: Marcos Roberto de Vasconcelos Lanza
• Support Opportunities: Research Projects - Thematic Grants