Nanopatterning and characterization of low-carbon steel to iron oxide nanostructures by short-duration anodization

Carbon steel (CFe) is a powerful material that can be used in various applications, practically including biomedical devices. Hematite nanoparticles (α-Fe 2 O 3 NPs) can be derived via electrochemically patterning CFe foil. In this approach, a suitable voltage was applied between the foil, which acts as a working electrode, and a graphite rod as a counter electrode. The process was carried out in a potential range of 7-11 V using 0.1 M Na 2 CO 3 electrolyte for 5 min. A maximal impact of the potential on the morphology, energy gap, and phonon vibrational modes was experimentally confirmed. Formation of α-Fe 2 O 3 rhombohedral crystals accumulated as different shapes of nanoparticles distributed on a porous surface was observed. Energy gaps between 2.18 eV and 2.75 eV were extracted from photoluminescence spectroscopy (PL). Also, Raman spectra revealed the existence of A 1 g, Eg, magnon modes of α-Fe 2 O 3 , and ε-Fe 2 O 3 . At higher voltage, dense semicircular NPs on the porous surface with lower impurities were fabricated. Thus, by adjusting the anodizing potential, modification of the nanostructures (NS) properties for biomedical, electronic, and nanoelectronic applications is possible.