A Facile One-Pot Approach to the Fabrication of Nanocellulose-Titanium Dioxide Nanocomposites with Promising Photocatalytic and Antimicrobial Activity

Roberta G Toro; Abeer M Adel; Tilde de Caro; Bruno Brunetti; Mona T Al-Shemy; Daniela Caschera

doi:10.3390/ma15165789

A Facile One-Pot Approach to the Fabrication of Nanocellulose-Titanium Dioxide Nanocomposites with Promising Photocatalytic and Antimicrobial Activity

Materials (Basel). 2022 Aug 22;15(16):5789. doi: 10.3390/ma15165789.

Authors

Roberta G Toro¹, Abeer M Adel², Tilde de Caro¹, Bruno Brunetti³, Mona T Al-Shemy², Daniela Caschera¹

Affiliations

¹ Institute for the Study of Nanostructured Materials, National Research Council, Via Salaria Km 29,300, Monterotondo Stazione, 00015 Rome, Italy.
² National Research Centre, Cellulose and Paper Department, 33El-Bohouth St. (Former El-Tahrir St.), Dokki, Giza P.O. Box 12622, Egypt.
³ Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza" Institute for the Study of Nanostructured Materials, National Research Council c/o, Piazzale Aldo Moro 5, 00185 Rome, Italy.

Abstract

The combination of cellulosic materials and metal oxide semiconductors can provide composites with superior functional properties compared to cellulose. By using nanocellulose derived from agricultural waste, we propose a one-pot and environmentally friendly approach to the synthesis of nanocellulose-TiO₂ (NC-TiO₂) nanocomposites with peculiar photocatalytic activity and antibacterial effects. The as-prepared NC-TiO₂ composites were fully characterized by different techniques, such as X-ray diffraction (XRD), μ-Raman, Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and diffuse reflectance spectroscopy (DRS). The results showed that well crystalline anatase TiO₂ nanoparticles of about 5-6 nm were obtained. The photocatalytic activity in particular was evaluated by using methyl orange (MO) solution as a target pollutant at different pH values. It was found that all the tested NC-TiO₂ nanocomposites showed stable photocatalytic activity, even after consecutive photocatalytic runs. In addition, NCT nanocomposites with higher TiO₂ content showed degradation efficiency of almost 99% towards MO after 180 min of UV illumination. Finally, NC-TiO₂ nanocomposites also showed intriguing antimicrobial properties, demonstrating to be effective against Gram-positive (Staphylococcus aureus, Bacillus subtilis) with 20-25 mm of inhibition zone and Gram-negative bacteria (Escherichia coli, Pseudomonas aeuroginosa) with 21-24 mm of inhibition zone, and fungi (Candida albicans) with 9-10 mm of inhibition zone.

Keywords: antimicrobial effects; hybrid nanocomposite; nanocellulose; nanotechnology; photocatalytic activity; photodegradation kinetic; titanium dioxide.

Grants and funding

The activities have been performed in the framework of the Joint Bilateral Agreement CNR/NRC (Italy/Egypt), Biennial Programme 2018–2019, for the project “Improvement of mechanical and barrier properties of biopolymer nano-composites for packaging applications”.