Theoretical study of (TM)FeO3 (TM=3d transition metals) molecular clusters

Time-dependent density functional theory-based calculations were carried out to comprehensively investigate the structural, electronic, and optoelectronic properties of series of molecular clusters (TM)FeO3 (with TM = 3d elements). The structures were studied at different levels of theory to explore the electronic energy levels, charge transfer analysis, and UV-Vis excitation spectra. In order to predict viable charge states and ordering of TM moments, the calculations were performed at different spin values to consider low-spin and high-spin configurations. The magnetic moments of the series of clusters in most stable configuration increased for the clusters with Sc to Fe and then decreased to Zn. The calculated values of magnetic moment and binding energy of the clusters show nearly a reciprocal trend. The substitution of TM, in order of increasing atom number from Sc to Zn, appeared to modify the optical response and shifted the absorption features of the clusters from ultraviolet to the visible region. The clusters CoFeO3, NiFeO3, CuFeO3, and ZnFeO3 are found suitable for coating on TiO2 and ZnO to increase light absorption in visible region. Owing to the findings of this study, the series of the clusters are predicted to be used in photocatalytic water splitting, photoanode material in dye-sensitized solar cell, supercapacitors, and electrode materials.