Manganese dioxide nanoparticles green synthesis using lemon and curcumin extracts and evaluation of photocatalytic activity

Abstract

Manganese dioxide nanoparticles (MnO2 NPs) were synthesized from aqueous manganese (II) acetate through the green route. Plant-based products such as lemon pulp and curcumin extracts were used as Mn2+ ion reducing and NPs stabilizing agents, respectively. UV–Visible spectrophotometer (UV–Vis) was used as a technique in measuring the relative yield of MnO2 NPs. The crystalline structure of synthesized MnO2 NPs was characterized using X-ray diffraction (XRD). Using Debye–Scherer equation, the average MnO2 NPs size was calculated as 41 nm. MnO2 NPs were also characterized using a scanning electron microscope (SEM) and FT-IR spectroscopy. MnO2 NPs photocatalytic activity was examined through methylene blue dye degradation under sunlight irradiation. Different variables such as exposure time, catalyst percentage, dye concentration, sunlight and dark conditions, and pH of the reaction medium were studied. MnO2 NPs were found to effectively degrade methylene blue dye about 95.3% in 7 h. Hence green synthesized MnO2 NPs could be used for water technology and industrial effluent treatment systems.