2,5-Diformylfuran production by photocatalytic selective oxidation of 5-hydroxymethylfurfural in water using MoS₂/CdIn₂S₄ flower-like heterojunctions

The selective oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-diformylfuran (DFF) is an important reaction for renewable biomass building blocks. Compared with thermal catalytic processes, photocat-alytic production of DFF from HMF has attracted tremendous attention. Herein, the MoS2/CdIn2S4 (MC) flower-like heterojunctions were prepared and considered as photocatalysts for selective oxidation of HMF into DFF under visible-light irradiation in aqueous solution. Results demonstrated MoS2 in MC heterojunction could promote the separation of photoexcited electron-hole pairs, while the amount of MoS2 dropping was proved influenced on the photocatalytic performance. 80.93% of DFF selectivity was realized when using 12.5% MC as photocatalyst. In addition, the MC catalyst also showed great potential in transformation of other biomass derived benzyl-and furyl-alcohols. The catalytic mechanism suggested that O-2(-) was the decisive active radical for HMF oxidation. Therefore, the MC heterojunction could be applied in photocatalytic conversion of biomass to valuable chemicals under ambient condition. (C) 2022 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.