Selective superoxide radical generation for glucose photoreforming into arabinose

Biomass photorefinery to produce fuels and valuable chemicals is a promising approach to alleviating the energy crisis and achieving carbon neutrality. However, precisely modulating the photocatalytic conversion of biomass into value-added chemicals is still challenging. Here we demonstrate a feasible strategy to selectively produce arabinose via oriented glucose oxidation to gluconic acid, followed by the decarboxylation process for C1-C2 bond cleavage. To realize this process, gold nanoparticles (Au NPs) modified carbon nitride (AuCN) is rationally designed to regulate the electron transfer behavior of pristine carbon nitride from a two-electron pathway to a single-electron pathway. This allows selective production of superoxide (O2−) from oxygen reduction reaction which triggers glucose oxidation into gluconic acid. In addition, the arabinose production is synergistically promoted by the improved charge separation efficiency and extended visible-light absorption via localized surface plasmon resonance (LSPR) of Au nanoparticles. This work demonstrates an example of a mechanism-guided catalyst design to improve biofuels/chemicals production from biomass photorefinery.