laser and solar light-induced degradation of pollutant dyes using bi-plasmonic ag-au nanoparticles-decorated magnetic tio2 for textile wastewater treatment

Eight eco-friendly, and magnetically-separable heterogeneous photocatalysts including five au nanoparticles (nps) modified magnetic tio2@fe3o4 nps and three ag-au bi-plasmonic nps-decorated tio2@fe3o4 nps with enhanced photocatalytic performance under visible light were synthesized and used for photodegradation of methyl orange (mo) as a model pollutant in textile wastewater samples. the photocatalytic activity was assessed using two radiation sources namely, an intense linear 532-nm laser and a continuous solar-simulated xenon lamp. compared to the tio2 alone, the prepared photocatalysts revealed efficient photocatalytic activity in visible region due to the presence of two localized surface plasmon resonance (lspr)-generated hot electrons from excited au and ag nps and reached to about 98% in 60 min. in addition, the results demonstrated that the photocatalysts have different degradation performance with respect to the type of applied light sources and also to the composition/shell thickness of plasmonic layer. the langmuir-hinshelwood adsorption model was used for evaluation of kinetics, degradation rate and half-life time of the reaction and it was concluded that the mechanism of mo degradation involves charge transfer and plasmon resonance energy transfer (pret) from these plasmonic nps to the tio2. on the other hand, the reusability studies revealed that the photocatalysts can be re-used for several cycles without losing its performance with a convenient magnetic separability. finally, it is shown that the prepared photocatalysts is successfully applied for degradation of organic pollutant in real textile wastewater