ECO-FRIENDLY SYNTHESIS OF SILVER NANOPARTICLES USED IN THE DEGRADATION OF ORGANIC DYES

ANCAFILU MENDOZA, A.; DURAN, K.; CORA JOFRE, F.; SCOLES, G. E.

Congreso; XL Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2022

The presence of chemical substances such as dyes in aqueous media constitutes a serious environmental problem due to their high toxicity and low biodegradability. In the last decades the synthesis of nanoparticles has experienced a great advance due to the high number of applications in fields such as cosmetics, industry and especially the environment. In the present study, the synthesis of nanoparticles was carried out using chemical substances of natural origin such as extracts of some plants instead of dangerous reductants such as sodium borohydride (NaBH4). The objective was to obtain silver nanoparticles (AgNPs) by the reduction of metal salts with extracts of buttercup (Calendula officinalis), pichana (Baccharis spartioides) and sunflower (Helianthus Petiolaris) and subsequent evaluation of the photocalytic activity in the dye methylene blue (AM). The characterization of the nanoparticles was performed using Transmission Electron Microscopy (TEM) and ultraviolet-visible spectroscopy. Size measurement was performed using Fiji software, visualizing the largest average particle size for buttercup AgNPs (38.8 nm), (18.7nm) for sunflower AgNPs and (24.3nm) for pichana AgNPs. To evaluate the degradation, a uvvis spectrophotometer was used to monitor the absorption band of the methylene blue dye at 664 nm and the % degradation of the dyes was calculated, taking into account that values below 50% are not good degraders of the dyes. From the analysis of the results, it can be inferred that AgNPs from the buttercup species are promising in dye degradation (% degradation 72) compared to pichana (24%) and girasolillo (17%). In addition, it was evidenced that the increase in the volume of AgNPs, in this case those obtained from buttercup extracts, leads to an increase in the rate of reduction or degradation of the dye.