Synthesis and Application of Nanocomposite Reinforced with Decorated Multi Walled Carbon Nanotube with Luminescence Quantum Dots

Amidst the COVID-19 pandemic, environmental problems such as energy crisis, global warming, and contamination from pathogenic micro-organisms are still prevailed and strongly demanded progress in high-performance energy storing and anti-microbial materials. The nanocomposites are materials that have earned large interest owing to their promising applications for countering global issues related to sustainable energy and a flourishing environment. Here, polypyrrole coated hybrid nanocomposites of multi-walled carbon nanotube and cadmium sulfide quantum dots named MCP were synthesized using facile and low-cost in-situ oxidative polymerization method. Characterization techniques confirmed the synthesis. Electrochemical studies showed that the nanocomposite 1-MCP showed an impressively higher super capacitance behavior in comparison to f-MWCNT, 7-MCP and 5-MCP. The improved performance of the nanocomposites was attributed mainly to the good conductivity of carbon nanotubes and polypyrrole, high surface area, and stability of the carbon nanotubes and the high electrocatalytic activity of the cadmium sulfide quantum dots. Owing to the synergistic effect of MWCNT, CdS, and PPy the synthesized ternary nanocomposite also inhibited the growth and multiplication of tested bacteria such as S. aureus, and E. coli completely within 24 h. On the whole, the assimilated nanocomposite MCP opens promising aspects for the development of upcoming energy storage devices and as an antibacterial agent.

Papaya peel waste carbon dots/reduced graphene oxide nanocomposite:From photocatalytic decomposition of methylene blue to antimicrobial activity

Carbon dots(CDs)have gained unprecedented attention as a novel luminescent zero-dimensional carbon nanomaterial owing to their diverse industrial applications.Herein,we reported the sus-tainable synthesis of fluorescent CDs from papaya peel waste,acting as a natural carbon orig-inator.As-prepared CDs and reduced graphene oxide(RGO)were fabricated in the composites through a facile one-step hydrothermal method.Synthesized RGO/CDs(RC)nanocomposites were characterized using spectroscopic,diffraction,and electron-microscopic techniques.Nanocom-posites with variable RGO to CD mass ratios were tested for photodegradation of textile dye methylene blue(MB).The highest photocatalytic activity(degradation efficiency of 87%in 135 min)was obtained in the nanocomposite containing a 2꞉1 mass ratio(RC2).The RGO sheets in the nanocomposite acted as media for electron acceptors,promoting the fast transfer and sep-aration of photoinduced electrons during CDs excitation,thus preventing the recombination of the electron and holes.Based on the agar well diffusion assay,the nanocomposites exhibited ex-cellent antibacterial activity than other tested materials against Bacillus subtilis(Gram-positive)and Pseudomonas aeruginosa(Gram-negative)bacterium.The largest inhibition zone area(22 mm),i.e.,the highest antimicrobial activity,was obtained in the nanocomposite tested against Gram-positive strains.Taken together,the synergistic effect of RGO and CDs enhanced the pho-tocatalytic and antibacterial performance of synthesized nanocomposite material.