Theoretical Investigation of Chromium Separation from Chromates Through Photon–Phonon Resonant Absorption

Chromium (Cr) is a vital metal utilized in materials physics, healthcare, and various other domains. In this study, we propose an eco-friendly method for separating Cr from potassium chromate (K2CrO4) based on photon–phonon resonance absorption theory. Using first-principles density functional theory calculations, we obtained the Raman and infrared spectra of K2CrO4 and assigned the vibrational modes to the peaks observed in the experimental spectra. We confirmed that the strongest infrared absorption peak corresponds to the Cr-O bond stretching vibration theoretically located at 931 cm−1. We propose employing a high-power terahertz laser at this resonant frequency for photothermal energy transfer. This approach is expected to enhance the efficiency of separating Cr from K2CrO4. Experimental investigations are expected in the future.