Nanoparticles of TiO ₂ on Electrospun Nanofibrous Membranes Composed of Kraft Lignin and Polyacrylonitrile for Enhanced Photocatalytic Degradation

Electrospun photocatalytic membranes have attracted significant attention for wastewater treatment due to their high specific surface area and structural tunability. However, the insufficient interfacial stability between catalysts and substrates often leads to nanoparticle detachment and performance deterioration during repeated use. In this work, a sustainable Titanium dioxide (TiO 2 )/Kraft lignin (KL)/polyacrylonitrile (PAN) composite nanofibrous membrane was fabricated via an electrospinning-assisted in situ hydrothermal strategy. KL serving as a green functional template, provides abundant anchoring and nucleation sites, enabling the uniform growth of TiO 2 nanoparticles. The synergistic integration of KL and TiO 2 not only enhances the interfacial stability and mechanical strength of the membrane but also broadens the light absorption range. The optimized TiO 2 /KL/ P 4̅ membrane exhibited a Rhodamine B removal efficiency of 90.5% within 2 h and a reaction rate constant 2.8× higher than of TiO 2 /PAN. In addition, the membrane maintained a removal efficiency above 81.8% after five consecutive cycles, demonstrating excellent reusability and structural stability. This work provides a sustainable strategy for the valorization of lignin toward the design of high-performance and durable photocatalytic materials for environmental remediation.