Ziziphus mauritiana-derived nitrogen-doped biogenic carbon dots: Eco-friendly catalysts for dye degradation and antibacterial applications.

In this study, the naturally available Ziziphus Mauritiana was used as a bioresource for the preparation of bifunctional nitrogen doped carbon dots (N-CDs). The doping of nitrogen into the graphitic carbon skeleton and the in-situ formation of N-CDs were systematically identified by the various structural and morphological studies. The green fluorescent N-CDs were used as active catalysts for the removal of Safranin-O dye and achieved 79 % removal efficiency. Furthermore, the prepared N-CDs were used to evaluate antibacterial activity with four different bacterial species, such as Shigella flexneri, Staphylococcus aureus, Streptococcus pyogenes, and Klebsiella pneumoniae. Amongst these, the highest antimicrobial activity was achieved against Klebsiella pneumonia, with a maximum zone of inhibition of 14.6 ± 1.12 at a concentration of 100 g mL-1. Thus, the obtained results demonstrate the cost efficient bifunctional application prospects of N-CDs to achieve significant catalytic and antibacterial activities.

Architectural MCM 41 was anchored to the Schiff base Co(II) complex to enhance methylene blue dye degradation and mimic activity.

A sequence of Schiff base Cobalt (II) Mobile Composite Matter 41 heterojunction (SBCo(II)-MCM 41) was prepared by post-synthetic protocols. Various characterization techniques were used to characterize the above samples and MCM 41: Morphology, functional groups, optical properties, crystalline nature, pore diameter, and binding energy by scanning electron microscope (SEM), High-resolution transition electron microscopy (HR-TEM), Fourier transform infrared spectroscopy (FTIR), Ultra Violet-Visible Spectroscopy (UV), X-ray powder diffraction (XRD), Brunauer-Emmett-Teller (BET) and X-ray Photoelectron Spectroscopy (XPS). After the encapsulation of SBCo(II) on the MCM 41, the intensity in the 100-plane in powder x-ray diffraction (XRD) decreased significantly; moreover, the light absorption behavior in UV analysis was improved. The change in the surface area and the decrease in the pore diameter of the sample were also demonstrated by the BET study. The XPS results confirmed the presence of Si, O, C, N, and Co in the SBCo(II)-MCM 41 complex. The photocatalytic performance of MCM 41 and SBCo(II)-MCM 41 materials tested by the degradation of methylene blue dye (MBD) shows that MCM 41 immobilization with SBCo(II)complex is rapidly degraded under natural sunlight irradiation. The optimized 10 mg SBCo(II)-MCM 41 catalyst concentrations showed effective enhancement with the highest efficiency of 98% achieved within 2 h compared to the other two SBCo(II)-MCM 41 concentrations. Moreover, the catalytic efficiency of SBCo(II)-MCM 41 showed a biomimetic reaction without using an oxidant, which exposed it as an effective catalyst for amine to imine conversion; it was useful in the medical field for enzymes with structural assembly.