Photoremediation of toxic dye from aqueous environment using monometallic and bimetallic quantum dots based nanocomposites

Iron nanoparticles (Fe NPs), monometallic Fe@carbon quantum dots (Fe@CQDs) and bimetallic Fe/Ag@carbon quantum dots (Fe/Ag@CQDs) nanocomposites were prepared by simple co-precipitation/reduction method. The nanoparticles (NPs), monometallic nanocomposite (MNCs) and bimetallic nanocomposite (BMNCs) were characterized using various techniques. The adsorptional/photocatalytic activity of NPs, MNCs, and BMNCs were investigated for the removal of fast green (FG) dye from aqueous medium. The degradation of FG dye under combined adsorptional/photocatalytic condition was efficient. The catalytic nature of synthesized NPs, MNCs and BMNCs was also explored for the oxidation of benzyl alcohol and esterification of acetic acid. For oxidation of benzyl alcohol with H₂O₂ in the presence of acetonitrile (ratio of butyl alcohol: H₂O₂ was 2:1) at temperature 80 °C, the Fe NPs gave maximum yield (87%). The esterification of acetic acid with ethyl, isopropyl and butyl alcohol showed that butyl alcohol gave maximum yield of 82%, 80%, and 84% for Fe NPs, Fe@CQDs MNCs and Fe/Ag@CQDs BMNCs, respectively.