Sulfated lignocellulose nanofibril based composite aerogel towards adsorption-photocatalytic removal of tetracycline.

ABSTRACT

The design-on-demand of lignocellulose nanofibril-based materials for contaminant disposal is worth exploring. Herein, we mildly extract sulfated lignocellulose nanofibrils from bagasse via a deep eutectic solvent-based approach, and use them as a matrix for TiO2 nanoparticles (TNPs) towards adsorption-photocatalytic synergistic removal of tetracycline (TC). The resultant lignocellulose-based nanocomposite aerogel possessing a high specific surface area (95.3 m2/g), surface charge density (1.78 mmol/g) and well-preserved lignocellulosic structure, strongly adsorbed TC with a maximum adsorption capacity of 70 mg/g via a combination of intermolecular interactions (i.e., hydrogen bonding and π-π stacking) and electrostatic forces. Furthermore, the excellent photocatalytic activity of uniformly distributed TNPs in combination with the outstanding adsorption capacity of nanocomposite aerogel can synergistically remove TC in a dynamic and continuous process, during which ~90 % TC (10 mg/L) was efficiently removed within 40 min. HPLC-MS was performed to reveal the degradation pathways of TC. Meanwhile, our developed nanocomposite aerogel demonstrated favorable structural stability and recyclability, which together supported its durability for environmental remediation.