Boosting electron kinetics of anatase TiO2 with carbon nanosheet for efficient photo-reforming of xylose into biomass-derived organic acids

Photocatalytic biorefinery catches an ocean of attention because of its environmental friendliness. It is widely known that photocatalytic performance of TiO2 is poor due to the wide bandgap and sluggish electron kinetics. Herein, biochar nanosheet and anatase TiO2 (denoted as a-TiO2 @MC) were combined to accelerate the charge separation/transfer and narrow the bandgap of TiO2, which is proved by UPS and Mott-Schottky plot analysis. With improved electron kinetics, comes excellent photocatalytic performance, which gave great yield of xylonic acid (52.26%) and lactic acid (49.22%). Furthermore, h+,·OH, and 1O2 exerted positive effects on the synthesis of biomass-derived organic acids, in which the h+ plays the major role in the biorefinery over a-TiO2 @MC, whereas the·O2- is not. 1000-fold scale-up experiment indicated that 69.1% of the photocatalytic performance was achieved when compared with the similar conditions irradiated by visible light. This work provides an efficient photocatalytic biorefinery via a facile and low-cost way.