A novel study on the preferential attachment of chromophore and auxochrome groups in azo dye adsorption on different greenly synthesized magnetite nanoparticles: investigation of the influence of the mediating plant extract's acidity

Abstract

The decrease in plant extract's acidity leads to the increase in Lewis acid site densities of greenly synthesized magnetite surfaces. The increase in Lewis acid site densities leads to the increase in azo dye adsorption yields.

Effect of methyl orange and Evans blue functional groups on photocatalytic activities of different magnetite nanoparticle surfaces

“…The adsorption of MO and EB has been conducted, at first, in dark ambient conditions to eliminate the effect of adsorption, followed by applying photocatalysis on residual solutions. Used protocol in adsorption experiments in dark ambient conditions and characterization techniques are described in our previous work [35].…”

“…In this paper, the photocatalytic reactions of functional groups (chromophores and auxochromes) of EB and MO on magnetite under UV-vis (365 nm) have been studied using four different magnetite NPs samples with the aim of investigating how EB and MO functional group contents affect the photocatalytic activities of magnetite, and hence deducing their effect on the development of photoactivated acid sites on Fe 3 O 4 surfaces. For this purpose, the adsorption of EB and MO on the four magnetite surfaces was conducted, at first, in dark ambient conditions (studied in our previous work [35]), to eliminate the impact of the adsorption. The dye/magnetite residual solutions were then used for photocatalytic reactions of the free functional groups of MO and EB on the four magnetite surfaces.…”

“…Table 3 shows that before the photocatalytic reactions of EB and MO, the adsorption capacities of EB were higher than those of MO on the four magnetite surfaces [35], however, after the photocatalytic reactions of EB/Fe…”