Integrated TiO2/CQDs photocatalytic and enzymatic pretreatment of hemp fibers under mild conditions for sustainable processing

Developing low-impact, energy-efficient pretreatment technologies is crucial for transitioning the bast fiber manufacturing toward cleaner textile production. This study introduces a hybrid pretreatment method that integrates visible-light-activated photocatalysis using TiO 2 /carbon quantum dots (TiO 2 /CQDs) with pectinase-assisted enzymatic hydrolysis to remove non-cellulosic gums from industrial hemp fibers. Operating at 30 °C and neutral pH, the system achieved 73.75 % lignin and 70.6 % pectin removal without compromising cellulose crystallinity or mechanical integrity. Morphological and spectroscopic analyses revealed effective disintegration of the amorphous matrix and exposure of clean fiber bundles. Mechanistic investigations confirmed the generation of reactive oxygen species (•O 2 − and h + ) under visible light, enabling selective delignification, while pectinase hydrolyzed polysaccharide binders, demonstrating synergistic enhancement of pretreatment efficiency compared to individual treatments. Preliminary energy consumption estimates indicate a 40–60 % reduction compared to conventional alkali-based processes. In addition, this alkali-free method could minimize wastewater generation. Hence, the proposed system offers a technically viable and environmentally preferable pathway toward clean and decentralized fiber manufacturing.