Facile fabrication of green nano pure CeO and Mn-decorated CeO with Cassia angustifolia seed extract in water refinement by optimal photodegradation kinetics of malachite green.

To eradicate the aquatic pollution caused by dyes, trendily the global researchers provide dedication to dye degradation using nanostructured photocatalyst. This research work is dedicated to explore an advanced, facile, bio-compact green fabricated nanostructure for water refinement. In this regard, plant-mediated syntheses of pure CeO and Mn-decorated CeO nano-powders have been inspected using seed extract of Cassia angustifolia. Investigations through UV-diffuse reflectance spectroscopy explored the significantly tuned band gap of Mn:CeO. FT-IR spectroscopy shows the existing functional groups of high-potential phenolic compounds, proteins, and amino acids in Cassia angustifolia act as reducing and capping agents involved in the green fabricated nanostructured samples. X-ray diffraction pattern has been exposed to crystalline cubic fluorite morphology in a single phase and it leads to a regulated optimized amount of Mn on CeO nanostructure. The FESEM analysis predicts the morphology of CeO in spherical and Mn:CeO in flower-like structure. The HRTEM analysis has portrayed particle size of CeO is 11 nm and tuned Mn:CeO nanostructure is 9 nm. The HRTEM images revealed the average particle size in the range 10-12 nm in CeO and 8-9 nm in 5 mol% Mn:CeO nanoparticles. It showed a decrease in average particle size with an increase in Mn concentration and the reduction in size may be due to the replacement of Ce(IV) with Mn(II) ions. The elemental composition in nanostructure was predicted using energy-dispersive X-ray analysis. The rapid photocatalytic degradation efficiency of malachite green was effectually performed and compared with the kinetics model of Mn:CeO and pure CeO nanostructures. From the augmented results, tuned Mn:CeO was found to act as the finest green fabricated photocatalyst in the amputation of lethal and carcinogenic dye.