Highly Selective Photocatalytic Oxidation Biomass Valorization Over Nb2O5/g-C3N4 Heterojunction

The selective biomass conversion of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfurane (DFF) through photocatalysis is of immense importance and has attracted much interest recently. However, its selectivity and conversion are still limited at present due to the lack of efficient photocatalysts to controllably activate the alcohol hydroxyl groups. Herein, Nb2O5/g-C3N4 type-II heterojunction photocatalysts to restrain the over-oxidation are developed, which successfully adjust the active oxygen species and enhance the separation and transfer of photoexcited carriers. The system achieves selective oxidation of HMF to DFF with high selectivity (>99%) and conversion (53%) via the inhibition of hydroxyl radicals (center dot OH) production arising from the decomposition of H2O2. Moreover, h(+) is the main active species for photocatalytic selective oxidation of HMF, and center dot O-2(-) is the second for that. Herein, it offers an effective strategy to effectively improve the high-selective conversion of biomass derivatives into high-value-added products.