Structural, electronic and optical properties of SrMnO₃ photocatalyst for dye degradation: Experimental and DFT study

Perovskite oxides (PO) are versatile multi-functional materials with wide range of applications. In current study, perovskite manganite (PM) SrMnO₃ has been synthesized via ultrasonic method followed by calcination at 600 °C. Morphology of PM having irregular shape and size was assessed by FESEM and hexagonal geometry with a crystallite size of 13.67 nm was determined by XRD studies. As-synthesized PM was further tested as photocatalyst for its dye degradation potential against malachite green (MG) and methylene blue (MB). In the presence of synthesized PM, degradation of both the dyes MG and MB was achieved in 12 min and 4.5 min with the percentage degradation of 80.26 % and 89.35 % respectively. The factors including pH and temperature affecting degradation of both the dyes were also studied. The structural and electronic attributes of SrMnO3 were calculated using DFT, according to which Sr and Mn have shown metallic character at Fermi level (Ef). The total and partial density of states (TDOS and PDOS respectively) explained the contribution of “d” and “p” orbitals of “Mn” and “O” respectively, and band gap was also calculated. The results of the current study advocate the synthesis of PM and related compounds followed by their successful applications as catalyst for dye degradation as well as many other fields involving the use of nanomaterials.