Electrospinning Machine| Performance-enhanced oxygen vacancy-rich C-TiO2 nanofiber membranes for dual photocatalytic/bactericidal water treatment

The acceleration of industrialization has led to increasingly severe water pollution, particularly from antibiotics and bacteria, posing significant threats to human health and ecosystems. Photocatalytic technology, as an advanced oxidation process, offers notable advantages such as cost-effectiveness, environmental friendliness, and high efficiency. It not only effectively degrades antibiotics in wastewater but also simultaneously inactivates pathogenic microorganisms, showing broad prospects in wastewater treatment. The performance of photocatalysts directly impacts the efficiency and cost of photocatalytic reactions, determining the effectiveness of antibiotic degradation and bacterial inactivation. Thus, preparing efficient, stable, and economical photocatalysts is crucial.

Recently, a team led by Prof. Wang Xinqiang and Assoc. Prof. Zhang Guanghui from Shandong University, in collaboration with Dr. Jin Xiaotong from Qilu University of Technology, published their latest research, "Performance-enhanced oxygen vacancy-rich C-TiO₂ nanofiber membranes for dual photocatalytic/bactericidal water treatment", in Separation and Purification Technology. Master's student Zhang Tianqi is the first author.

The researchers prepared flexible, self-supporting carbon (C)-doped titanium oxide (TiO₂) nanofiber membranes (CTNFMs) with high specific surface area via electrospinning combined with inert atmosphere heat treatment. These membranes exhibited excellent catalytic and antibacterial effects against tetracycline hydrochloride (TC), E. coli, and S. aureus. The fibers featured small grain size, fine diameter, and high aspect ratio. 

Fig. 1: Morphology comparison of T-NFMs and CT-NFMs.

The fibers exhibited small grain size, fine diameter, and high aspect ratio. C doping enabled the fibers to maintain smaller grains after high-temperature treatment, and CT-NFMs showed better flexibility than T-NFMs.

Fig. 2: Specific surface area and pore size distribution of NFMs.

Both NFMs displayed Type IV N₂ adsorption-desorption isotherms with H3 hysteresis loops, indicating mesoporous structures. The refined grains endowed the fibers with superior specific surface area, providing abundant active sites for catalytic reactions. CT-800 had the largest specific surface area (158.9 m²/g), 45 times that of T-800, and even CT-900 retained a significantly higher surface area than T-900.

Fig. 3: Catalytic performance of NFMs.

In TC degradation tests, CT-NFMs exhibited strong adsorption and fast catalytic rates, with CT-800 showing the highest performance.

Fig. 4: Antibacterial test of CT-800 against S. aureus.

CT-800 also demonstrated outstanding antibacterial activity, reducing E. coli and S. aureus concentrations by 99.76% and 94.78%, respectively, under both dark and light conditions, proving broad-spectrum efficacy.

Paper link::https://doi.org/10.1016/j.seppur.2025.134169