SDS capped Cu nanorods: photosynthesis, stability, and their catalytic activity for trypan blue oxidative degradation

Abstract

Sodium dodecyl sulfate (SDS) capped- Cu nanorods were prepared by using ascorbic acid under light limiting diode (LED) irradiation for the first time. The preliminary indications of CuNPs production were the appearance of yellow (Cu2O) and red-chocolate color (Cu0) in absence and presence of LED exposure at room temperature. The optical, spectroscopic and morphological properties of as-prepared NPs were characterized using UV–visible spectroscopy through the presence of a characteristic surface Plasmon resonance (SPR) band for Cu0 at 584 nm along with high absorbance at 800 nm for Cu2O. X-ray diffraction (XRD) shows that the red-chocolate color consist 90% metallic Cu0 and 9.7% Cu2O with face cubic center unit cell structure of CuNPs. Transmission electron microscope (TEM), energy dispersive X-ray (EDX), and scanning electron microscope (SEM) revealed that the CuNPs were nano-rods with an average length ranging from 300 to 350 nm. LED light assisted degradation of trypan blue (TB) was also investigated in presence of CuNPs and K2S2O8. The existence of sulfate radicals (SO4-•) and hydroxly radicals (HO•) generated during the degradation were identified by using different radical scavengers. Degradation follows first-order kinetics with respect to K2S2O8 concentrations. The oxidative dissolution of CuNPs was also observed along with the TB degradation. Based on the absorbance changes at 590 nm, the degradation and dissolution mechanisms were proposed and discussed.