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

TL;DR

This study demonstrates that fluorine doping of Nb2O5 nanoparticles enhances their electrocatalytic performance for H2O2 production via the oxygen reduction reaction, leading to higher yields and lower energy consumption.

Contribution

It introduces a novel fluorine doping method for Nb2O5 nanoparticles that significantly improves their electrocatalytic efficiency for H2O2 generation.

Findings

F-doped Nb2O5 showed 65-98% higher H2O2 yields than undoped catalysts.

F doping increased lattice disorder and oxygenated species, enhancing electron transfer.

The optimized catalyst reduced energy consumption and increased current efficiency.

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 F-doped 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.