Tea Polyphenols Functionalized and Reduced Graphene Oxide-ZnO Composites for Selective Pb²⁺ Removal and Enhanced Antibacterial Activity

Abstract

New materials with good purification of water quality (heavy metal ions removal and inhibition of bacteria) have increasingly attracted more research attentions. Considering the advantages of zinc oxide (ZnO) and tea polyphenol functionalized and reduced graphene oxide (TPG), the TPG-ZnO composites were prepared under moderate hydrothermal method and characterized by various methods. Lead ions (Pb2+) and Streptococcus mutans (S. mutans) were used to evaluate the adsorption capacity and antimicrobial activity of the TPG-ZnO, respectively. The influencing factors for heavy metal ions removal (pH, contact time), adsorption kinetics, and isotherms were discussed in this article. Furthermore, their antibacterial properties against S. mutans were investigated by counting of colony-forming units (CFU), scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM). Results showed that the novel TPG-ZnO composites presented higher adsorption efficiency for Pb2+ (98.92%) compared with pure ZnO and enhanced antibacterial activity effects (99.99%) towards S. mutans, compared with pure ZnO and TPG (P < 0.05). The TPG-ZnO composites are therefore promising water purification materials for application in high-efficient removal of heavy metal ions and inhibition of bacterial growth.

Carbon Nanomaterials for the Treatment of Heavy Metal-Contaminated Water and Environmental Remediation

“…Zheng et al designed nanocomposites by fabrication of zinc oxide with tea polyphenol with reduced graphene oxide (TPG-ZnO). Designed material was applied for the removal of heavy metal ions with an added advantage of antibacterial properties [143]. They applied this material for the removal of Pb 2+ ions from aqueous solution with adsorption efficiency of 98.9%, and the adsorbent was found to possess antibacterial properties against Streptococcus mutans with 99% eradication [143].…”

“…Designed material was applied for the removal of heavy metal ions with an added advantage of antibacterial properties [143]. They applied this material for the removal of Pb 2+ ions from aqueous solution with adsorption efficiency of 98.9%, and the adsorbent was found to possess antibacterial properties against Streptococcus mutans with 99% eradication [143]. Mousavi et al designed nanocomposites of graphene oxide with iron oxide magnetite nanoparticles Fe 3 O 4 and applied them for the removal of Pb 2+ ions from water and the material showed 98% removal efficiency with a capacity of 126.6 mg/g [144].…”

Ecofriendly Approach for Treatment of Heavy-Metal-Contaminated Water Using Activated Carbon of Kernel Shell of Oil Palm

“…Different carbonaceous materials have been used for the removal of heavy metals, namely single-wall carbon nanotubes (SWCNTs), functionalized-SWCNTs, multiwall carbon nanotubes (MWCNTs), functionalized-MWCNTs, graphene and graphene oxide, etc. [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49]. A comprehensive review was recently published on the application of carbon nanomaterials in water treatment and environmental remediation [14].…”

A multifunctional ATP-generating system by reduced graphene oxide-based scaffold repairs neuronal injury by improving mitochondrial function and restoring bioelectricity conduction

“…Graphene is a type of classical two-dimensional nanomaterial with good biocompatibility and electrical conductivity [ 39 ]. The excellent biocompatibility of RGO nanomaterials and its better electrical conductivity than graphene and graphene oxide were verified by a variety of studies [ 40 , 41 ]. 1% (W/WPCL) RGO and 1% (W/WPCL) MLT has respectively reported that have less cytotoxicity and could promote cell adhesion and proliferation on PCL scaffolds [ 20 , 29 ].…”