A fascinating one-pot solvent-, catalyst-, and template-free synthesis process to facilitate a single-phase crystalline hexagonal type-II luminescent Eu2O2CO3 organization comprised of nanoplates is demonstrated. The thermolysis (700 degrees C) of europium acetate in a closed stainless steel reactor under autogenic pressure [-3 MPa] yielded Eu2O2CO3 superstructures. Powder X-ray diffraction, high-resolution transmission electron microscopy, and Raman measurements confirmed the structure. Fourier transform infrared spectroscopy, energy-dispersive spectrometry, and CHNS analysis verified the composition. Scanning electron microscopy corroborated the morphology of the new Eu2O2CO3 compound, and the primary luminescence properties are accounted.