Visible light-induced photo-Fenton dehydration of fructose into 5-hydroxymethylfurfural over ZnFe2O4-coated Ag nanowires

ZnFe2O4-coated Ag nanowires (Ag@ZnFe2O4 NWs) were prepared for the photo-Fenton induced dehydration of fructose into 5-hydroxymethylfurfural (5-HMF) in visible light region. Effects of ZnFe2O4 content, volume ratio of dimethyl sulfoxide (DMSO) to deionized water, reaction temperature, fructose dosage, H2O2 content, pH values, inorganic ions, and quenchers on the fructose conversion, 5-HMF yield, and 5-HMF selectivity were performed in detail. Among these obtained composites, BrOnsted acidic Ag@ZnFe2O4 NWs with Ag NWs diameter of around 20 nm and ZnFe2O4 coating of 6.13 wt% exhibit the best photo-Fenton catalytic activity for the conversion of fructose into 5-HMF, and slightly deactivate after five cycle times. The surface plasmon resonance effect of Ag NWs and the synergistic effect between ZnFe2O4 and Ag NWs are favorable for the visible light absorption and the efficient transfer and separation of charge carriers. DMSO as well as OH radical plays the vital role in the photo-Fenton induced dehydration of fructose into 5-HMF.