Facile synthesis of mesoporous NiCo2O4 fibers with enhanced photocatalytic performance for the degradation of methyl red under visible light irradiation

Mesoporous NiCo2O4 fibers were synthesized by the coordination co-precipitation-decomposition method using ammonia as morphology-controller. The as-prepared NiCo2O4 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis absorption spectra and photoluminescence (PL) analysis. The as-prepared NiCo2O4 materials showed typical intertwined porous nanofibrous structures with specific surface area of 74.6 m2/g and average pore size of 11.79 nm. The mesoporous NiCo2O4 fibers showed remarkably enhanced photocatalytic performance towards methyl red (MR) degradation under visible-light irradiation compared to the Co3O4 and NiO. The degradation efficiency of MR over the NiCo2O4 reached up to 95.1% after irradiation for 120 min. Superior photocatalytic activity of 1D NiCo2O4 fibers can be attributed to the higher light harvesting capacity resulted from large surface area and unique mesoporous structure. Finally, a possible mechanism for the photodegradation of MR over the NiCo2O4 was proposed.