Effect of fluorine doping on the electrocatalytic properties of Nb2O5 for H2O2 electrogeneration

Author(s)

Trench, Aline B. ; Moura, Joao Paulo C. ; Fernandes, Caio Machado ; Santos, Mauro C.

• Document type: Journal article
• Source: JOURNAL OF ELECTROANALYTICAL CHEMISTRY; v. 992, p. 10-pg., 2025-09-01.

Abstract

The oxygen reduction reaction (ORR) via the 2-electron mechanism is an efficient way to produce hydrogen peroxide (H2O2) under mild conditions. This study examines the modification of Vulcan XC72 carbon with fluorine (F)-doped niobium oxide (Nb2O5) nanoparticles at varying molar ratios (0, 0.005, 0.01, 0.02). The Fdoped Nb2O5 nanoparticles were synthesized using the oxidizing peroxide method and then incorporated into Vulcan XC72 carbon via impregnation. Characterization techniques included X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), contact angle measurements, and X-ray photoelectron spectroscopy (XPS). Electrochemical evaluation using the rotating ring disk electrode method revealed that Vulcan XC72 modified with 1.0 % F-doped Nb2O5 exhibited the best ORR performance. When used as a gas diffusion electrode, this electrocatalyst produced more H2O2 at all applied potentials than the pure and Nb2O5-modified Vulcan XC72 carbon. At potentials of -0.7 V and -1.3 V, the proposed electrocatalyst achieved H2O2 yields 65 % and 98 % higher than the Nb2O5-modified electrocatalyst. Furthermore, it presented lower energy consumption and higher current efficiency than the other electrocatalysts compared in this study. The enhanced performance is attributed to F doping, which increased Nb2O5 lattice distortion and disorder, improving electron availability for ORR. Additionally, F-doped electrocatalysts exhibited more oxygenated species and greater hydrophilicity, facilitating O2 adsorption, transport, and electron transfer. These properties significantly enhanced H2O2 electrogeneration efficiency while reducing energy consumption. (AU)

• 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
• FAPESP's process: 21/05364-7 - Nanostructured electrocatalysts based on manganese and tungsten oxides supported on carbon for electrogeneration of hydrogen peroxide and electrochemical degradation of ciprofloxacino
• Grantee: João Paulo Carvalho Moura
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 22/10484-4 - Application of low-cost nanomaterials for degradation of endocrine disruptors through advanced electrochemical oxidation processes under the influence of a magnetic field
• Grantee: Caio Machado Fernandes
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 21/14394-7 - Use of Vulcan XC-72 carbon modified with fluorine and/or cerium doped niobium nanostructures in the electrogeneration of H2O2 for degradation of endocrine disruptors by advanced electrochemical oxidative processes
• Grantee: Aline Barrios Trench
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• 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