I. Neelakanta Reddy

Enhanced visible-light photocatalytic performance of Fe 3 O 4 nanopyramids for water splitting and dye degradation

Iron oxide (Fe3O4) pyramid nanostructures were synthesized via a co-precipitation method, without using surfactants or template, for photocatalytic and photoelectrocatalytic activities. The as-made Fe3O4 was characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), UV–vis spectroscopy, photoluminescence spectroscopy, N2 adsorption–desorption analysis, and X-ray photoelectron spectroscopy (XPS). The data clearly demonstrate that the Fe3O4 nanostructures display excellent crystallinity, uniform morphology with a Brunauer–Emmett–Teller (BET) surface area of 52.95xa0m2xa0g−1, and an optical bandgap of 2.17xa0eV, which allows them to serve as outstanding catalysts under visible irradiation. The highest photocatalytic activity of ~u200997% was achieved in the degradation of rhodamine B under visible irradiation, with a degradation rate constant of 0.0322xa0min−1 at room temperature. Further, electrochemical studies demonstrated that the Fe3O4 electrode possesses good electrocatalytic activity in 0.1xa0M KOH electrolyte. The highest photocurrent density of 1.2xa0×xa010−4xa0mAxa0cm−2 was observed in the water splitting reaction. The Fe3O4 nanostructures exhibited superior performance in terms of both dye degradation and photoelectrochemical activity.