Au coupled with TiO2-Fe3O4 magneto-photocatalysts for the highly selective synthesis of 2,5‑furandicarboxylic acid from biomass feedstock

As a renewable platform chemical, 2, 5-furandicarboxylic acid (FDCA) provides a sustainable alternative to petroleum-derived terephthalic acid with vital strategic importance. Achieving the efficient conversion of 5-hydroxymethylfurfural (HMF) to FDCA under environmentally friendly conditions is of great practical significance. Herein, an Au/Fe 3 O 4 /TiO 2 photocatalyst was prepared by first synthesising an Fe 3 O 4 /TiO 2 composite via a hydrothermal method, followed by amination and subsequent reduction of Au nanoparticles. Furthermore, multiple characterisations confirmed the successful loading of Fe 3 O 4 and Au nanoparticles, while abundant Fe signals were detected adjacent to the Au nanoparticles. Under simulated solar irradiation, an FDCA yield of 97% was achieved within 15 h, demonstrating the superior catalytic performance of the Au/Fe 3 O 4 /TiO 2 photocatalyst. Moreover, the photocatalytic activity remained at 85% after five consecutive cycles, indicating its excellent cycling stability and reusability. Simultaneously, superior photocatalytic activity and stability were attained owing to the strong synergistic effect among Au nanoparticles, Fe 3 O 4 and TiO 2 . In addition, the photocatalytic oxidation mechanism of HMF to FDCA over Au/Fe 3 O 4 /TiO 2 was elucidated, wherein h + , 1 O 2 and •O 2 - contributed to the production of FDCA. This study provides a promising strategy for the efficient photocatalytic conversion of HMF to FDCA under mild conditions.