posted on 2020-04-01, 13:34authored byVaishali
N. Sonkusare, Ratiram Gomaji Chaudhary, Ganesh S. Bhusari, Aniruddha Mondal, Ajay K. Potbhare, Raghvendra Kumar Mishra, Harjeet D. Juneja, Ahmed A. Abdala
The
present article reports a facile approach to fabrication of
mesoporous octahedron-shaped tricobalt tetroxide nanoparticles (Co3O4 NPs) with a very narrow size distribution for
eco-friendly remediation of toxic dyes. Co3O4 NPs were fabricated by a sol–gel process
using cobalt chloride hexahydrate (CoCl2·6H2O) and monosodium succinate (C4H5O4Na) as a chelating/structure-directing agent and sodium dodecyl sulfate
as a surfactant. Moreover, the phase structure, elemental composition,
and thermal and morphological facets of Co3O4 NPs were investigated using XRD, FT-IR, EDS, Raman, XPS, TGA, SEM,
and TEM techniques. The face-centered cubic spinel crystalline structure
of the Co3O4 NPs was confirmed by XRD and SEM,
and TEM analysis revealed their octahedron morphology with a smooth
surface. Moreover, the narrow pore size distribution and the mesoporous
nature of the Co3O4 NPs were confirmed by Brunauer–Emmett–Teller
measurements. The photocatalytic activity of Co3O4 NPs for degradation of methyl red (MR), Eriochrome Black-T (EBT),
bromophenol blue (BPB), and malachite green (MG) was examined under
visible light irradiation, and the kinetics of the dye degradation
was pseudo-zero-order with the rate constant in the order of MR >
EBT > MG > BPB. Furthermore, the mechanism of photo-disintegration
mechanism of the dye was examined by a scavenging test using liquid
chromatography–mass chromatography, and its excellent photodegradation
activities were attributed to the photogenerated holes (h+), superoxide (O2–) anions, and hydroxyl
(·OH) radicals. Finally, the synergistic effect of
the nano-interconnected channels with octahedron geometry, mesoporous
nature, and charge transfer properties along with photogenerated charge
separations leads to an enhanced Co3O4 photocatalytic
activity.