Green synthesis of SrO nanoparticles using leaf extract of Albizia julibrissin and its recyclable photocatalytic activity: an eco-friendly approach for treatment of industrial wastewater

The present work unveils the reusable photocatalytic action of strontium oxide (SrO) nanoparticles synthesized using Albizia julibrissin plant extract via the co-precipitation method. The material and its synthesis reveal an eco-friendly approach that provides new insight into synthesizing the photocatalyst. The plant extract controls the parameters such as particle size, morphology, structure and other characteristic features of the synthesized material which are important aspects of a photocatalyst. The microscopy images of the as-synthesized SrO nanoparticles show that the particles exhibit spherical morphology with a rough surface and agglomeration of particles was also observed. The spherical morphology of SrO nanoparticles leads to a higher aspect ratio and assists in higher adsorption of pollutant dye. Using a Tauc plot, an energy bandgap of 2.64 eV is estimated for SrO nanoparticles, which is favorable for absorption of visible light. The synergic effect of structural and morphology parameters leads to an enhanced photo-degradation/pollutant removal efficiency of 87.4% for cationic methylene blue dye under visible light irradiation. In addition, the reusability of the SrO photocatalyst over four cycles is tested, and the results indicate that SrO can be proven to be an effective eco-friendly photocatalyst.