Green Synthesis via Eucalyptus globulus L. Extract of Ag-TiO2 Catalyst: Antimicrobial Activity Evaluation toward Water Disinfection Process

Abstract

The problem of water pollution by persistent substances and microorganisms requires solutions that materials such as silver-modified titanium dioxide can provide due to their excellent photocatalytic and antimicrobial properties. However, the synthesis methods conventionally used to obtain these materials involve toxic chemical reagents such as sodium borohydride (NaBH4). The search for alternative synthesis methods that use environmentally friendly substances, such as the biosynthesis method, was evaluated. Silver-titanium dioxide (Ag-TiO2) was synthesized by a Eucalyptus globulus L. extract as a reductive agent through sol-gel and microwave-assisted sol-gel processes. Four different solvents were tested to extract secondary metabolites to determine their roles in reducing silver nanoparticles. Titanium dioxide nanoparticles with sizes from 11 to 14 nm were obtained in the anatase phase, and no narrowing of the bandgap was observed (3.1–3.2 eV) for the Ag-TiO2 materials compared with the pure TiO2. Interestingly, the bacterial inhibition values were close to 100%, suggesting an effective antimicrobial mechanism related to the properties of silver. Finally, by the physicochemical characterization of the materials and their antimicrobial properties, it was possible to obtain a suitable biosynthesized Ag-TiO2 material as a green option for water disinfection that may be compared to the conventional methods.

Padina boergesenii mediated synthesis of Se-ZnO bimetallic nanoparticles for effective anticancer activity

“…The peaks at 2974 cm −1 and 2,887 cm −1 are associated with hydrocarbon (C-H) vibrations of alkene ( Mane et al, 2021 ; Hossain et al, 2023 ). The peak at 1,651 cm −1 corresponds to -C=O and C=C stretching vibrations ( Torres-Liminana et al, 2022 ). The absorption bands at 1,382 cm −1 and 1,327 cm −1 are associated with C-N stretching of aromatic amine groups and N-O symmetric stretching of nitro compounds, respectively ( Rastogi and Arunachalam, 2012 ; Nagalingam et al, 2018 ).…”

Synthesis of CoFe2O4 through Wet Ferritization Method Using an Aqueous Extract of Eucalyptus Leaves

“…Literature data mention that the IR spectra recorded for different types of eucalyptus extract revealed the functional groups which could be the responsible candidates for the obtained nanoparticles [28][29][30][31].…”

“…Previous studies revealed the use of eucalyptus extract, which is easy to obtain and sustainable, in the synthesis of metal nanoparticles such as Ag, Zn, Fe [25,27,28] and metal oxide TiO 2 , ZnO, La 2 O 3 [29][30][31]. These nanoparticles could be good candidates for biomedical, ecological, and agricultural applications.…”

Eucalyptus globulus Mediated Green Synthesis of Environmentally Benign Metal Based Nanostructures: A Review

“…Torres-LimiNana et al [ 140 ] studied the comparative behavior of TiO 2, Ag-TiO 2 NPs, and pristine Ag NPs as a water disinfectant synthesized using the green method (EG extract) and conventional method (sodium borohydride NaBH 4 ). The EG extract was prepared using four different solvents (water, methanol, ethanol, and water/methanol), which were later used for NPs synthesis.…”