Synthesis and application of functional Prussian blue nanoparticles for toxic dye degradation

Functional Prussian blue nanoparticles (PBN) is invented as photo-Fenton catalyst and conferred inexpensive, eco-friendly and more effective photodegradation approach to treat the dyestuff Rhodamine B using natural solar light. The photo-Fenton catalyst with four different crystallite size of functional PBN as PBN1, PBN2, PBN3 and PBN4 between 53 to 13 nm were fabricated by chemical reduction method using 2-(3,4-Epoxycyclohexyl) ethyltrimethoxysilane (EETMSi) and Cyclohexanone. EETMSi precisely control the morphology and crystallite size of the catalyst. The as-synthesized photo-Fenton catalysts were characterized by XRD, FTIR, EDX, DLS, HR-TEM, UV/Vis spectroscopy, XPS and BET techniques. Functional PBN/H2O2 combination presented a very promising approach for complete RhB degradation in the acidic condition via N-de-ethylation under solar light irradiation. RhB photodegradation efficiency has been evaluated under different condition to understand the influential role of different parameters; catalyst concentration, H2O2 concentration, size of catalyst and pH. The Kinetic rate constant for RhB photodegradation is found in the order of; (PBN4/H2O2) > (PBN3/H2O2) > (PBN2/H2O2) > (PBN1/H2O2) > (H2O2). The kinetics of the degradation process is found to obey Langmuir-Hinshelwood rate law and approved Pseudo-first order kinetics. The investigation also assessed the quicker (1.5 min) and more effective photodegradation approach for 100% removal of RhB justifying most efficient inexpensive photocatalyst compared to other reported methods. Similarly, the concurrently generated reactive oxygen species (ROS) was detected by EPR technique. The catalyst can be recovered even after five times of repetition. Further Analytical methods LC/MS and COD analysis were utilized to identify the degraded end product and extent of mineralization.