Synthesis of a high dielectric constant graphene supported iron oxide and its electrocatalytic activity in a H2O2 fuel cell and as an efficient photocatalyst

Abstract

The present work focuses on the study of the dielectric properties of iron oxide and graphene supported iron oxide and their relation towards electrocatalytic activity. Graphene supported iron oxide was synthesized and characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy, UV-Vis spectroscopy, LCR meter. The synthesized composite has a small particle size of 32.3 nm and a high surface area of 8.10 m² g⁻¹. Graphene supported iron oxide also showed a enhanced dielectric constant of 10.4 and an ac conductivity of 4.78 × 10⁻⁷ S cm⁻¹ at 1 MHz. The composite was also studied for its electrocatalytic activity in a H₂O₂ fuel cell. The H₂O₂ fuel cell performance of iron oxide was high in the presence of graphene with a power density of 0.03 mW cm⁻² and current density of 0.5 mA cm⁻². A further improvement in the H₂O₂ fuel cell performance was obtained using hydrazine sulfate with a power density of 2.6 mW cm⁻² and current density of 7.8 mA cm⁻². Synthesized iron oxide/graphene also showed enhanced photocatalytic activity towards methylene blue dye degradation and good cycling stability.