Furfural mediated synthesis of silver nanoparticles for photocatalytic reduction of hexavalent chromium

Abstract

Industrial effluents contain various toxic substances and the removal or conversion of these substances to non-toxic products is highly crucial. The work emphasized on the green synthesis of silver nanoparticles with furfural, a promising derivative of lignocellulosic biomass (FAgNPs) for exploring its catalytic efficiency in the photocatalytic reduction of hexavalent chromium [Cr(VI)]. A peak at 410 nm was obtained with a molar ratio of 1:1 (silver nitrate to furfural) at pH 9. The effect of initial concentration of Cr(VI), pH, catalyst dosage, time on reduction of Cr(VI) has been investigated. The photocatalytic efficiency of 1 g/L FAgNPs was studied and 9% to 88% Cr(VI) reduction was observed with decreasing Cr(VI) concentration at pH 2. Under UV illumination, electron–hole pairs generated in FAgNPs resulted in the migration of photo generated electrons for the reduction process which is highly pH dependent. The photocatalytic reduction process can be explained by Langmuir–Hinshelwood model and fits into pseudo-first order kinetics. HaCaT cells exposed to Cr(VI) after being treated with FAgNPs for various time period exhibited an increase in cell viability with time which further substantiated its efficiency. Therefore, the study was an attempt to prepare a nanomaterial by a simple, facile method for the photocatalytic reduction of hexavalent chromium with a focus on environmental remediation.