Enhanced photoluminescence, optical and photocatalytic performance of NiCo2O4 nanoflakes for photonic applications

초록

Nickel cobalt oxide (NiCo2O4) nanoflakes are synthesized using solvothermal method and systematically investigated to correlate structural, optical and photocatalytic characteristics. The powder X-ray diffraction patterns confirm the formation of a phase pure cubic spinel phase structure of NiCo2O4 with an average crystallite size of 16 nm. Fourier transform infrared spectra (FTIR) indicate a prominent band near 651 and 556 cm-1 which is attributed to Co-O and Ni-O stretching vibrations and confirmed spinel lattice formation. Field-emission scanning electron microscopy (FE-SEM) reveals a morphology of interconnected nanoscale network which supports efficient charge transport. Energy-dispersive X-ray spectroscopy (EDX) spectra and elemental mapping verify uniform distribution of Ni, Co and O. UV-Visible explores a strong ultraviolet absorption 370 nm with an optical bandgap of 1.70 eV favouring photo-induced charge excitation. Photoluminescence measurements indicate reduced emission peak at 368 nm in the ultraviolet region, suggesting suppressed electron-hole recombination and improved charge separation, which enhances photocatalytic activity with a high degradation efficiency of 97.2% under UV irradiation. Collectively, the results of the study demonstrate that NiCo2O4 nanoflakes represent a prospective candidate for multifunctional material suitable for advanced photocatalytic, electrocatalytic and optoelectronic applications.

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