Publication: Surface oxidation of steel waste for iron oxide nanosheets formation and Assessment on their semiconducting properties
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Date
2025-08-08
Authors
Wan, Jian Khai
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Abstract
The increasing global demand for clean energy solutions has driven interest in green hydrogen production through photoelectrochemical (PEC) water splitting. This study explores the development of PEC photoanode using scrap steel as a substrate to synthesize the α-Fe2O3 nanosheets. After cutting into desired size, the samples are ground, polished, and cleaned. The research is divided into two main phases: (i) thermal oxidation of scrap steel to form iron oxide nanosheets, and (ii) enhancement of PEC performance through the deposition of reduced graphene oxide (rGO) via
electrophoretic deposition (EPD). In first phase, various oxidation temperatures (400 °C, 500 °C, 600 °C) and durations (30, 60, and 120 minutes) were applied in a tube furnace under a humidified atmosphere to evaluate the influence of thermal parameters on surface morphology and PEC activity. The optimal condition for nanosheet growth was observed at 600 °C for 120 minutes, with well-formed nanostructured surface that enhanced charge transport and light absorption. In the second phase, rGO provided by Toyohashi University of Technology was deposited onto the nanowire surface at varying voltages (40 V, 60 V, 80 V). Characterization techniques including Field Emission Scanning Electron Microscopy (FESEM), X-ray Diffraction (XRD), X-ray fluorescence (XRF), Raman spectroscopy, and UV-Vis spectroscopy were used to analyse the surface morphology, crystallinity, elemental composition, and optical properties of the photoanodes. The PEC performance was evaluated through linear sweep voltammetry (LSV), with the highest photocurrent density recorded at 0.2462 mA/cm2 and 0.8960 mA/cm2 (1.23 V vs. RHE) before and after rGO deposition. The results proves that nanostructuring the surface and coupling with rGO can enhance the photoelectrochemical performance of the hematite-based photoanode.