Study of structural, optical, and electrochemical properties of Zn-doped hematite nanoparticles

Abstract

Hematite (α-Fe₂O₃) is a promising material for oxygen evolution reactions but is limited by poor conductivity and rapid charge recombination. This study explores zinc-doped hematite (ZFO) nanoparticles synthesised at 700, 800, and 900 °C to enhance these properties. The Zn doping improved conductivity and optical properties, while the calcination temperature influenced structural and electrochemical characteristics. ZFO nanoparticles were integrated into screen-printed carbon electrodes (SPC-ZFO) and evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). CV revealed diffusion-controlled electron transfer with strong linearity (R2 ≈ 0.99), and SPC-ZFO electrodes showed higher current responses than bare electrodes, indicating enhanced surface reactivity. EIS results confirmed improved electron mobility, particularly for SPC-ZFO calcined at 900 °C. These findings highlight the role of zinc doping and thermal treatment in optimizing hematite for energy and environmental applications.

HIGHLIGHTS • Zn-doped α-Fe₂O₃ (ZFO) was synthesised at varying temps. (700, 800, and 900 °C) • The structural, optical, and electrochemical properties of ZFO were studied. • Zinc doping enhances hematite's conductivity and addresses its inherent limitations. • SPC-ZFO electrodes showed higher current responses than bare electrodes in cyclic voltammetry. • Electrochemical impedance spectroscopy revealed improved electron mobility at 900 °C. • The study demonstrates the potential of ZFO nanomaterials for Advanced materials applications.