Iron oxide nanoparticles coated with green tea extract as a novel magnetite reductant and stabilizer sorbent for silver ions: Synthetic application of Fe₃O₄@green tea/Ag nanoparticles as magnetically separable and reusable nanocatalyst for reduction of 4‐nitrophenol

Abstract

Green tea extract having many phenolic hydroxyl and carbonyl functional groups in its molecular framework can be used in the modification of Fe 3 O 4 nanoparticles. Moreover, the feasibility of complexation of polyphenols with silver ions in aqueous solution can improve the surface properties and capacity of the Fe 3 O 4 @green tea extract nanoparticles (Fe 3 O 4 @GTE NPs) for sorption and reduction of silver ions. Therefore, the novel Fe 3 O 4 @GTE NPs nano-sorbent has potential ability as both reducing and stabilizing agent for immobilization of silver nanoparticles to make a novel magnetic silver nanocatalyst (Fe 3 O 4 @GTE/Ag NPs). Inductively coupled plasma analysis, transmission and scanning electron microscopies, energy-dispersive X-ray and Fourier transform infrared spectroscopies, and vibrating sample magnetometry were used to characterize the catalyst. Fe 3 O 4 @GTE/Ag NPs shows high catalytic activity as a recyclable nanocatalyst for the reduction of 4-nitrophenol at room temperature.

Multifunctional hybrid nanoplatform based on Fe3O4@Ag NPs for nitric oxide delivery: development, characterization, therapeutic efficacy, and hemocompatibility

“…The magnetization saturation (Ms) values obtained were 76.8, 56.1, and 56.9 emu g −1 for Fe 3 O 4 NPs, Fe 3 O 4 @Ag NPs, and Fe 3 O 4 @Ag/TCS NPs, respectively. The Ms values obtained for Fe 3 O 4 NPs are similar to the reported for this material in the literature, with values from 62 to 90 emu g −1 , confirming the magnetic properties expected for this nanomaterial [27,35]. For Fe 3 O 4 @Ag NPs and Fe 3 O 4 @Ag/TCS NPs, lower Ms values are observed, in accordance to the addition of diamagnetic layers (Ag, phytochemicals derived from green tea, and TCS) [36].…”

Green synthesis of silver nanoparticles using Thymus kotschyanus extract and evaluation of their antioxidant, antibacterial and cytotoxic effects

“…Striking antibacterial and antioxidant properties of silver nanoparticles have made it one of most attractive metal . Recently biosynthesis of Silver nanoparticles has been studied with various plants part as olive leaf, mulberry leaves, leaf extract of Indian plants, Thymbra spicata s , Stachys lavandulifolia , green tea , Sesamum indicum seed, banana peel, oak fruit bark and Eucalyptus chapmaniana . Thymus Kotschyanus species belongs to the Lamiaceae family and widely used in modern and traditional medicine .…”

Tea polyphenol-assisted green synthesis of Ag-nanodiamond hybrid and its catalytic activity towards 4-nitrophenol reduction

“…To evaluate and compare the catalytic activity of different catalysts, the standardized catalyst activity constant A = k/m was used to evaluate the catalytic performance of the current catalyst, where k is rate constant, m is the catalyst mass of 1 mL reaction solution (Table 2). As Table 2, the current Ag-TPND catalyst is better than most of the Ag-based catalysts reported in the literature (43,(62)(63)(64)(65). To futher evaluate the intrinsic catalytic activity of the catalyst, initial turnover frequency (TOF) values in the first two minutes, that is, the number of 4-NP molecules reacted per mol Ag per hour, were calculated to be 256.2 h −1 .…”

“…Plant polyphenols represent a large family of compounds consisted of epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC), and tannic acid (TA), and so on. Inspired by their natural bonding and antioxidant properties, plant polyphenols have recently received extensive attention and research interest in different fields including surface modification, nano-synthesis, composites, to name a few (31,38,(41)(42)(43)(44)(45)(46)(47)(48). Among many plant polyphenols, green tea polyphenols (TPs) is the most widely studied one because it is the most readily available (49).…”