Enhanced photoluminescence and structural insights of MgCoNiO4 nanocomposites for optoelectronic devices

MgCoNiO₄ nanocomposites possess excellent structural, optical, and thermal properties, making them promising candidates for use in light-emitting diode (LED) devices and other photonic technologies. MgCoNiO₄ nanocomposites were synthesized via the co-precipitation method for the first time. Structural, optical, vibrational, and morphological characterizations using PXRD, FTIR, UV–Vis, Raman spectroscopy, FESEM, and EDX confirm the formation of highly crystalline spinel structures with nanoscale grains and uniform elemental distribution. It was verified by powder X-ray diffraction (PXRD) that the samples form a cubic spinel structure during crystallization, and the average crystallite size is 25–35 nm. For vibrational mode investigation, Raman spectroscopy was used, and for functional group and chemical bond identification, FTIR spectroscopy was employed. Using UV–Visible–NIR spectrophotometry, we investigated optical properties and found a sharp absorption peak at around 760 nm, and the approximate optical band gap is concerning 4.9 eV. The surface appearance and microstructure were examined using scanning electron microscopy (SEM), among an average particle dimension of about 70–80 nm, while the elemental composition was determined using energy-dispersive X-ray analysis (EDAX). Further studies were carried out using X-ray photoelectron spectroscopy (XPS) to investigate the surface chemical states. Photoluminescence (PL) spectroscopy revealed a strong blue–green luminescence with an emission peak at 501 nm, making it an ideal candidate for use in optoelectronic devices. The measured optical band gap (~ 4.9 eV) and photoluminescence suggest potential for catalytic and energy storage applications.