Surfactant-assisted hydrothermal pretreatment for co- production of reducing sugars and carbon quantum dots from lignocellulosic biomass

A facile and environmentally friendly strategy was proposed for co-production of reducing sugars and carbon quantum dots (CQDs) from lignocellulosic biomass (LCB) by one-pot surfactant-assisted hydrothermal pretreatment. Compared with hydrothermal pretreatment, the addition of surfactants (Tween 40) significantly increased the sugars concentration and effective quantum yield (QY). The highest reducing sugars concentration and QY of CQDs was up to 22.47 g/L and 1.9% respectively. After surfactant-assisted pretreatment, the crystallinity index of LCB residue increased and then decreased with the addition amount of Tween 40. Moreover, the conversion rate of cellulose and hemicellulose reached 95.1% and 95.4% respectively, 122.2% and 41.1% higher than that without Tween 40. It was also found that surfactant-assisted hydrothermal pretreatment had the same improvement effect on increasing the sugar production of other LCB. The results showed that surfactant-assisted hydrothermal pretreatment was a promising and universal method for developing biomass-based products.