One-Step Method for Preparing Dispersive Tea Polyphenol/Graphene Nanosheets Enhanced with Anticorrosion Performance

Abstract

Water-dispersible and anticorrosion nanocomposites have attracted extensive attention. In this study, tea polyphenol (TP)/graphene (GE) was fabricated with a one-step route. The preparation and modification of graphene nanosheets was carried out by graphene employing tea polyphenols as reduction and functionalization reagents. Our study adopted a nontoxic reductant without an extra functionalization reagent. This method is convenient, inexpensive, and environmentally friendly. The final functionalized graphene nanosheets had a single-layer structure. For evaluating performance, Raman spectroscopy was adapted for evaluating π–π interactions between TP and graphene. Elemental and structural composition was analyzed using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Sample morphology was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results indicated that the TP could effectively augment the dispersive performance of graphene in the solution. The durable anticorrosion capacity of the epoxy matrix noticeably increased after adding the appropriate amount of tea polyphenols–graphene (TPG) (0.3 wt.%). Electrochemical impedance spectroscopy (EIS) studies showed that the impedance of artificial defects was enhanced. The anticorrosion property was attributed to the uniform dispersion of graphene by adding TP.

Natural Polyphenols and the Corrosion Protection of Steel: Recent Advances and Future Perspectives for Green and Promising Strategies

“…Several surface pre-treatments have been tested for the steel substrates before corrosion protection coating deposition: degreasing and grinding [80,113,114], degreasing and blasting [115][116][117], grinding and etching [118], rusting [119], or surface preparation according to SSPC-SP5 and SP1 standards [88,120]. As specified by SSPC-Surface Preparation (SP)-1, a solvent is used to remove soluble substances from steel, such as oil, dirt, and drawing or cutting compounds [121].…”

“…Tannic acid is the most widely used additive [113,119,133,134] together with tannins from different sources, such as tara [80], Pinus radiata [90,120], mangrove bark [135], quebracho [115], black wattle [114], and even tannins recovered from the wastewater of the vegetable tanning process [118]. In addition, acetylated kraft lignin [116] and tea polyphenols [117] have also been considered for these purposes.…”