Biomaterial (Garlic and Chitosan)-Doped WO₃-TiO₂ Hybrid Nanocomposites: Their Solar Light Photocatalytic and Antibacterial Activities

Abstract

In this work, WO 3 -TiO 2 , chitosan-blended WO 3 -TiO 2 , and garlic-loaded WO 3 -TiO 2 nanocomposites were synthesized by the sol−gel and precipitation technique. The synthesized nanocomposites were characterized by XRD, FE-SEM, HR-TEM, EDX, UV-DRS, FT-IR, and TG-DTA analysis. The photocatalytic efficiency of the three synthesized nanocomposites on the degradation of dyes such as rhodamine B (Rh-B), methylene blue (MB), and methyl orange (MO) as organic pollutants was evaluated under solar light irradiation. The results show that garlic-loaded WO 3 -TiO 2 nanocomposites act as an excellent photocatalyst than chitosan-blended WO 3 -TiO 2 and WO 3 -TiO 2 nanocomposites. Further, the antimicrobial activity of the synthesized nanocomposites was examined against Gram-negative bacteria (Escherichia coli) by the well diffusion method. Garlic-loaded WO 3 -doped TiO 2 nanocomposites have demonstrated good antibacterial activity over chitosan-blended WO 3 -TiO 2 nanocomposites and WO 3 -TiO 2 nanocomposites. The possible reason may be the presence of organic sulfur compounds in garlic.

Tungsten Trioxide and Its TiO2 Mixed Composites for the Photocatalytic Degradation of NOx and Bacteria (Escherichia coli) Inactivation

“…Finally, while the synthesized catalysts were active in NO 2 photodegradation, they were inert to the antibacterial activity under visible light irradiation, in line with the scientific literature [36]. As expected, in the WO3@TiO2 composites, the intensity of the diffraction peaks of WO3 declines by decreasing the percentage of WO3; on the contrary, anatase peaks intensity increases or appears with the higher concentration of TiO2 in each composite.…”

A biopolymer functionalized two-dimensional WS2@TiO2 nanocomposite for in vitro biomedical and photocatalytic applications: facile synthesis and characterization

“…Furthermore, CS plays an important role in charge transfer; it may act as a bridge between TiO 2 and WS 2 to enhance electron mobility at the interface. 55,56 Fig. S11 (ESI †) illustrates the photocatalytic mechanism of MB dye by the CS/WS 2 @TiO 2 catalyst and is discussed in the ESI.…”

Recent Progress of Advanced Metal-Oxide Nanocomposites for Effective and Low-Cost Antimicrobial Activates: A Review

“…Their result shows that the inhabitation zone is greater than the individual nanoparticle, i.e., 7.71 mm for S. aureus and 13.40 mm for E. coli bacterial pathogens [76]. Dhanalekshmi et al [77] synthesized novel garlic-loaded WO 3 -TiO 2 chitosan (CS)blended WO 3 -TiO 2 and WO 3 -TiO 2 nanocomposites by a simple sol-gel and precipitation methods. The antimicrobial activities of WO 3 -TiO 2 , CS-blended WO 3 -TiO 2 , and garlicloaded WO 3 -TiO 2 were determined by using a WD method employing Gram-negative bacteria (E. coli) with four different concentrations (250, 500, 750, and 1,000 g).…”

“…Allicin compound decomposes into other sulfurous compounds such as diallyl disulfide and ajoene. Sulfurous compounds interact with the cell wall of bacteria by rupturing their layer and changing their total metabolic activity, thereby inhibiting the bacterial activity of the cell [77]. CdO-CuO-ZnO (CCZ NC) mixed metal-oxide nanocomposite was proposed for antibacterial and photocatalytic activities in 2021 by Kannan et al [74].…”

“…FIGURE 7: Comparable inhibition zone (mm) for WO 3 -TiO 2 , chitosan blended WO 3 -TiO 2 , and garlic-loaded WO 3 -TiO 2 nanocomposites in an E. coli bacterial strain[77].…”