Enhanced visible-light photocatalytic performance of Fe3O4 nanopyramids for water splitting and dye degradation

• Published in: Journal of solid state electrochemistry 2018-11, Vol.22 (11), p.3535-3546
• Main Authors: Reddy, I. Neelakanta, Sreedhar, Adem, Reddy, Ch. Venkata, Shim, Jaesool, Cho, Migyung, Kim, Dongseob, Gwag, Jin Seog, Yoo, Kisoo
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Catalytic activity; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Degradation; Dyes; Electrochemistry; Energy dispersive X ray spectroscopy; Energy Storage; Energy transmission; Iron oxides; Irradiation; Morphology; Nanostructure; Original Paper; Oxidation; Photocatalysis; Photoelectric effect; Photoelectric emission; Photoluminescence; Physical Chemistry; Rhodamine; Scanning electron microscopy; Spectrum analysis; Transmission electron microscopy; Water splitting; X ray photoelectron spectroscopy; X-ray diffraction
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-018-4054-4

Iron oxide (Fe 3 O 4 ) pyramid nanostructures were synthesized via a co-precipitation method, without using surfactants or template, for photocatalytic and photoelectrocatalytic activities. The as-made Fe 3 O 4 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, N 2 adsorption–desorption analysis, and X-ray photoelectron spectroscopy (XPS). The data clearly demonstrate that the Fe 3 O 4 nanostructures display excellent crystallinity, uniform morphology with a Brunauer–Emmett–Teller (BET) surface area of 52.95 m 2  g −1 , and an optical bandgap of 2.17 eV, which allows them to serve as outstanding catalysts under visible irradiation. The highest photocatalytic activity of ~ 97% was achieved in the degradation of rhodamine B under visible irradiation, with a degradation rate constant of 0.0322 min −1 at room temperature. Further, electrochemical studies demonstrated that the Fe 3 O 4 electrode possesses good electrocatalytic activity in 0.1 M KOH electrolyte. The highest photocurrent density of 1.2 × 10 −4  mA cm −2 was observed in the water splitting reaction. The Fe 3 O 4 nanostructures exhibited superior performance in terms of both dye degradation and photoelectrochemical activity.