Microbial pathogens and bulk amounts of industrial toxic wastes in water are an alarming situation to humans and a continuous threat to aquatic life. In this study, multifunctional silver and graphene nanocomposites (Ag)1−x(GNPs)x [25% (x = 0.25), 50% (x = 0.50) and 75% (x = 0.75) of GNPs] were synthesized via ex situ approach. Further, the synthesized nanocomposites were explored for their physicochemical characteristics, such as vibrational modes (Raman spectroscopic analysis), optical properties (UV visible spectroscopic analysis), antibacterial and photocatalytic applications. We investigated the antimicrobial activity of silver and graphene nanocomposites (Ag-GNPs), and the results showed that Ag-GNPs nanocomposites exhibit remarkably improved antimicrobial activity (28.78% (E. coli), 31.34% (S. aureus) and 30.31% (P. aeruginosa) growth inhibition, which might be due to increase in surface area of silver nanoparticles (AgNPs)). Furthermore, we investigated the photocatalytic activity of silver (AgNPs) and graphene (GNPs) nanocomposites in varying ratios. Interestingly, the Ag-GNPs nanocomposites show improved photocatalytic activity (78.55% degradation) as compared to AgNPs (54.35%), which can be an effective candidate for removing the toxicity of dyes. Hence, it is emphatically concluded that Ag-GNPs hold very active behavior towards the decolorization of dyes and could be a potential candidate for the treatment of wastewater and possible pathogenic control over microbes. In the future, we also recommend different other in vitro biological and environmental applications of silver and graphene nanocomposites.
The catalysts utilized for oxidative desulfurization have acquired significant attention and ability to improve the quality of the fuel oil by removing sulfur. In this work, the catalysts used for oxidative desulfurization include CoWO4 and Bi2WO6 with graphitic carbon nitride (g-C3N4) as support were synthesized by the one-pot hydrothermal method. Graphitic carbon nitride was obtained by thermal polycondensation of melamine at 550°C for 5 h. These catalysts were homogeneously dispersed on the surface of the support and their structure, morphology, and properties were determined by different characterization techniques (Powder X-Ray Diffractometer, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy and Energy Dispersive X-Ray Spectroscopy, Specific Surface Area (Brunauer, Emmett and Teller (SBET)). The parameters that affect the efficiency of the desulfurization process such as catalyst amount, amount of oxidizing agent, and reaction temperature have been optimized thoroughly. The oxidative desulfurization reaction was studied in terms of kinetics which shows that reaction is pseudo first order. The thermodynamic studies revealed that the reaction is endothermic and spontaneous in nature. The results determined that the catalytic efficiency for the removal of sulfur (as dibenzothiophene) is more than 90% in the presence of support (g-C3N4) to obtain sulfur free fuel.
In the present study, we aimed to synthesize (Ag)1−x(GNPs)x nanocomposites in variable ratios (25% GNPs–Ag, 50% GNPs–Ag, and 75% GNPs–Ag) via an ex situ approach to investigate the incremental effects of GNPs (graphene nanoparticles) on AgNPs (silver nanoparticles). The prepared nanocomposites were successfully characterized using different microscopic and spectroscopic techniques, including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet spectroscopy, and Raman spectroscopic analysis. For the evaluation of morphological aspects, shape, and percentage elemental composition, SEM and EDX analyses were employed. The bioactivities of the synthesized nanocomposites were briefly investigated. The antifungal activity of (Ag)1−x(GNPs)x nanocomposites was reported to be 25% for AgNPs and 66.25% using 50% GNPs–Ag against Alternaria alternata. The synthesized nanocomposites were further evaluated for cytotoxic potential against U87 cancer cell lines with improved results (for pure AgNPs IC50: ~150 µg/mL, for 50% GNPs–Ag IC50: ~12.5 µg/mL). The photocatalytic properties of the nanocomposites were determined against the toxic dye Congo red, and the percentage degradation was recorded as 38.35% for AgNPs and 98.7% for 50% GNPs–Ag. Hence, from the results, it is concluded that silver nanoparticles with carbon derivatives (graphene) have strong anticancer and antifungal properties. Dye degradation strongly confirmed the photocatalytic potential of Ag-graphene nanocomposites in the removal of toxicity present in organic water pollutants.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.