In Situ Formation of Ag Nanoparticles in Mesoporous TiO2 Films Decorated on Bamboo via Self-Sacrificing Reduction to Synthesize Nanocomposites with Efficient Antifungal Activity

Abstract

We developed a novel green approach for the in situ fabrication of Ag NPs in mesoporous TiO2 films via the bamboo self-sacrificing reduction of Ag(NH3)2+ ions, which can inhibit fungal growth on the bamboo surface. Mesoporous anatase TiO2 (MT) films were first synthesized on bamboo via a hydrothermal method. Then, Ag NPs with a 5.3 nm mean diameter were incorporated into the pore channels of optimal MT/bamboo (MTB) samples at room temperature without the addition of reducing agents, such that the Ag NPs were almost entirely embedded into the MT films. Our analysis indicated that the solubilized lignin from bamboo, which is rich in oxygen-containing functional groups, serves as a green reductant for reducing the Ag(NH3)2+ ions to Ag NPs. Antifungal experiments with Trichoderma viride under dark conditions highlighted that the antifungal activity of the Ag/MT/bamboo samples were greater than those of naked bamboo, MTB, and Ag/bamboo, suggesting that these hybrid nanomaterials produce a synergistic antifungal effect that is unrelated to photoactivity. The inhibition of Penicillium citrinum effectively followed a similar trend. This newly developed bamboo protection method may provide a sustainable, eco-friendly, and efficient method for enhancing the antifungal characteristics of traditional bamboo, having the potential to prolong the service life of bamboo materials, particularly under dark conditions.

Visible-Light-Driven Ag-Modified TiO2 Thin Films Anchored on Bamboo Material with Antifungal Memory Activity against Aspergillus niger

“…These results indicate that the AB samples had poor resistance to A. niger. Our previous work similarly showed that nanosized Ag-treated bamboo samples have poor resistance to P. citrinum and T. viride [35]. In addition, we did not observe any Our previous work similarly showed that nanosized Ag-treated bamboo samples have poor resistance to P. citrinum and T. viride [35].…”

“…Our previous work similarly showed that nanosized Ag-treated bamboo samples have poor resistance to P. citrinum and T. viride [35]. In addition, we did not observe any Our previous work similarly showed that nanosized Ag-treated bamboo samples have poor resistance to P. citrinum and T. viride [35]. In addition, we did not observe any mycelial growth on the surfaces of the TB, ATB-5, ATB-10, ATB-30, and ATB-200 samples after incubation for five days.…”

“…In step II, when [Ag(NH 3 ) 2 ] + was introduced, positively charged anions were drawn to a negatively charged TiO 2 surface covered by F − or OH groups owing to an attractive electrostatic force [35]. The silver mirror reaction generally involves the chemical reduction of the Ag compound into elemental Ag in the solution.…”

Resistance to Growth of Molds for Wood Modified with Hydrophobic Hybrid Silica Gel Containing Copper Amine Complexes

“…In addition, organic fungicides are always toxic and harmful to humans and livestock. Recently, a number of studies have developed novel inorganic mildew preventives with lower toxicity, including nano-ZnO [ 14 , 15 , 16 ], TiO 2 [ 17 , 18 , 19 ], CuO [ 20 ], graphene [ 21 ], Ag, or a combination of them [ 22 , 23 , 24 , 25 ]. These nano-sized inorganics form a protective coating layer at wooden products surface.…”

Silver Nano/Microparticles: Modification and Applications 2.0

“…Mori et al evaluated the antibacterial and cytotoxicity properties of silver nanowires and their composites with carbon nanotubes for biomedical applications [ 36 ]. Li et al reported a simple, sustainable, and environmentally friendly method for the in situ fabrication of silver nanoparticles in mesoporous TiO 2 films decorated on bamboo via self-sacrificing reduction to synthesize nanocomposites with an efficient antifungal activity [ 37 ]. The composite films-endowed bamboo exhibited an excellent antifungal activity to T. viride and P. citrinum.…”