Facile synthesis of Au–TiO2/Bacterial cellulose aerogel nanocomposites with enhanced photocatalytic degradation of methylene blue under UV irradiation

Abstract

The Au–TiO2/Bacterial cellulose aerogel nanocomposites (Au–TiO2/BC NCs) with remarkable photocatalytic properties and designed to solve agglomeration and reusability challenges in wastewater treatment have been successfully synthesized. The integration of gold nanoparticles (Au NPs) with TiO2, in conjunction with bacterial cellulose (BC) serving as a three-dimensional nanostructure, resulted in the formation of Au–TiO2/BC NCs through mechanical compositing, a confirmation obtained through various characterization techniques including XRD, SEM, SEM-EDS, TEM, TEM-EDS, BET, XPS, FT-IR, Spectrofluorometer, Raman, and UV–vis spectroscopy. The combination of Au–TiO2 nanoparticles with BC showcased homogeneous coverage over BC nanostructures, attributed to BC's unique properties, particularly its surface hydroxyl groups that prevent TiO2 agglomeration, along with uniform distribution of Au nanoparticles on TiO2 layers. Photocatalytic activity, assessed through methylene blue (MB) degradation under both UV and direct sunlight irradiation, demonstrated significantly improved efficiency with AuNPs, achieving approximately 90% degradation in the Au–TiO2/BC NCs under UV irradiation. The synthesized NCs exhibited stability with a slight performance reduction after cyclic tests, indicating potential for wastewater treatment applications under diverse light conditions. The integration of Au NPs onto TiO2 surfaces amplified light-induced reactions, addressing critical challenges in environmental remediation, particularly in the degradation of persistent environmental pollutants. This study offers valuable insights, positioning Au–TiO2/BC NCs as promising candidates for sustainable environmental remediation, emphasizing reusability, enhanced photocatalytic performance, and a straightforward synthesis process under both UV and direct sunlight irradiation.