Heterogeneous Photocatalytic Conversion of Biomass-Derived Sugars into 5-Hydroxymethylfurfural over AgFe₂O₄/TiO₂–SO₃H Nanocomposite

Photocatalytic transformation of biomass to high-value chemicals is an economical and environmentally friendly way to solve global problems of energy and sustainability. As a means to achieve this, we developed a simple and efficient photocatalytic system for the conversion of sugars to 5-hydroxymethylfurfural (5-HMF), which is a versatile intermediate for the production of biofuels and fine chemicals. Herein, the AgFe2O4/TiO2 nanocomposite was synthesized by a facile methodology and then modified with propyl sulfonic acid groups to obtain an acidic photocatalyst. The prepared photocatalyst was well analyzed by various experimentations to assess its compositional, structural, and morphological properties. The use of this photocatalyst for the photocatalytic dehydration of fructose to 5-HMF conversion provided excellent 5-HMF yield (98%) under white LED light irradiation and at a moderate temperature (75 °C). The recycle experiment exhibited that the photocatalyst can be reused for six times without substantial activity decrease. Moreover, the developed photocatalysis system was also able to convert other abundant biomass resources (glucose, sucrose, maltose, and cellulose) to 5-HMF with satisfactory yields. This research not only provides a green and efficient catalytic protocol for 5-HMF production but also paves the way to design novel AgFe2O4-based composite materials with well-tailored photocatalytic features.